Wyoming Framework Water Plan - Living Rivers Home Page

Wyoming Water Development
Commission
October 2007
WYOMING FRAMEWORK
WATER PLAN
VOLUME I

This report was prepared by:
WWC Engineering
Hinckley Consulting
Collins Planning Associates
Greenwood Mapping, Inc.
States West Water Resources Corporation

Wyoming Framework Water Plan
Volume I
October 2007
This report was prepared for:
Wyoming Water Development Commission
6920 Yellowtail Road
Cheyenne, WY 82002
This report was prepared by:
WWC Engineering
Hinckley Consulting
Collins Planning Associates
Greenwood Mapping, Inc.
States West Water Resources Corporation

I, Murray T. Schroeder, a Wyoming registered Professional Engineer, certify that this
Wyoming Framework Water Plan, Volume I report was prepared by me or under my
direct supervision. (The original signature and stamp are available at the Water
Development Office.)
I, Bern Hinckley, a Wyoming registered Professional Geologist, certify that this
Wyoming Framework Water Plan, Volume I report was prepared by me or under my
direct supervision. (The original signature and stamp are available at the Water
Development Office.)

TABLE OF CONTENTS
1.0-INTRODUCTION………………………………………………………………………….1-1
1.1 OVERVIEW…………………………………………………………………………….1-1
1.2 NEED FOR BASIN PLANNING AND FRAMEWORK PLAN……………………....1-2
1.3 BASIN PLANS…………………………………………………………………………1-3
2.0-WEB TOOL………………………………………………………………………...………2-1
2.1 SEARCHING…………………………………………………………………………...2-1
2.2 DATABASE TABLES………………………………………………………………….2-1
2.3 MAPS AND FIGURES…………………………………………………………………2-1
3.0-SETTING…………………………………………………………………………………...3-1
3.1 PHYSICAL SETTING………………………………………………………………….3-1
3.1.1 Land Area and Ownership……………………………………………………...3-1
3.1.2 Physiography…………………………………………………………………...3-3
Topography…………………………………………………………………………....3-3
Drainage System……………………………………………………………………...3-3
3.1.3 Climate…………………………………………………………………………3-4
3.2 SOCIOECONOMIC SETTING………………………………………………………...3-4
3.2.1 Historic Populations Growth…………………………………………………...3-4
3.2.2 Aging Populations……………………………………………………………...3-6
3.2.3 Employment and Labor Force Participants…………………………………….3-7
3.2.4 Key Economic and Water Use Sectors…………………………………………3-8
Agriculture……………………………………………………………………………3-9
Livestock……………………………………………………………………………..3-10
Crops………………………………………………………………………………...3-10
Industrial…………………………………………………………………………….3-10
Municipal and Domestic…………………………………………………………….3-11
Recreation, Travel and Tourism……………………………………………………..3-12
Environmental……………………………………………………………………….3-12
3.3 LEGAL AND INSTITUTIONAL SETTING…………………………………………3-12
3.3.1 Wyoming Water Rights……………………………………………………….3-12
3.3.2 Interstate Compacts, International Treaty, Court Decrees and Contracts and
Agreements……………………………………………………………………3-14
Amended Bear River Compact (1978)………………………………………………3-14
Upper Division………………………………………………………………………3-14
Central Division……………………………………………………………………..3-14
Lower Division………………………………………………………………………3-15
Belle Fourche River Compact (1943)…………………………………………….....3-15
Colorado River Compacts (1922 and 1948)………………………………………...3-15
Upper Niobrara River Compact (1962)……………………………………………..3-16
Snake River Compact (1948)………………………………………………………...3-16
Yellowstone River Compact (1950)………………………………………………….3-16
International Treaty…………………………………………………………………3-17
Court Decrees……………………………………………………………………….3-17
North Platte River…………………………………………………………………...3-17
Laramie River………………………………………………………………………..3-20
Teton and South Leigh Creeks………………………………………………………3-21

Wind/Bighorn River Basin…………………………………………………………..3-21
3.3.3 Contracts and Agreements……….……………………………………………3-22
Green River Basin…………………………………………………………………...3-22
Fontenelle Reservoir Contract………………………………………………………3-22
High Savery Reservoir Contract…………………………………………………….3-23
Platte River Basin……………………………………………………………………3-23
Cooperative Agreement……………………………………………………………...3-23
Platte River Recovery Implementation Program (PRRIP)…….……………………3-23
Glendo Reservoir Contract………………………………………………………….3-24
Snake/Salt River Basin………………………………………………………………3-24
Wind/Bighorn River Basin…………………………………………………………..3-24
3.3.4 Water Environmental Laws….………………………………………………..3-25
Groundwater Quality………………………………………………………………..3-26
Surface Water Quality……………………………………………………………….3-29
3.3.5 Federal Environmental Laws………………………………………………….3-29
Endangered Species Act……………………………………………………………..3-29
National Environmental Laws……………………………………………………….3-30
Clean Water Act……………………………………………………………………..3-30
3.4 REFERENCES………………………………………………………………………...3-30
4.0 RESOURCES…………………………………………………………………………..4-1
4.1 INTRODUCTION………………………………………………………………………4-1
4.2 GENERAL………………………………………………………………………………4-1
4.3 SURFACE WATER RESOURCES…………………………………………………….4-2
4.3.1 Quantity………………………………………………………………………...4-2
4.3.2 Water Quality…………………………………………………………………..4-3
4.4 GROUNDWATER RESOURCES……………………………………………………...4-4
4.4.1 Groundwater Overview………………………………………………………...4-4
4.4.2 Aquifer Classification…………………………………………………………..4-5
Major Aquifers………………………………………………………………………..4-6
Alluvial………………………………………………………………………………..4-6
Sandstone……………………………………………………………………………..4-6
Limestone……………………………………………………………………………..4-6
Minor Aquifers………………………………………………………………………..4-7
Marginal Aquifers…………………………………………………………………….4-7
Major Aquitards………………………………………………………………………4-7
Unclassified...................................................................................................................4-7
Aquifer Location………………………………………………………………………4-8
4.4.3 Historical Aquifer Performance………………………………………………..4-9
4.4.4 Groundwater Quality…………………………………………………………..4-9
4.4.5 Groundwater Associated with Energy Development…………………………4-10
4.5 REFERENCES………………………………………………………………………...4-10
5.0 USE……………………………………………………………………………………..5-1
5.1 INTRODUCITON………………………………………………………………………5-1
5.2 AGRICULTURAL WATER USE……………………………………………………...5-1
5.2.1 Introduction…………………………………………………………………….5-1
5.2.2 Agricultural Water Use Methodology………………………………………….5-1
5.2.3 Irrigated Acreage……………………………………………………………….5-2
5.2.4 Irrigated Crops………………………………………………………………….5-3
5.2.5 Diversions………………………………………………………………………5-5

Surface Water…………………………………………………………………………5-5
Groundwater………………………………………………………………………….5-7
Theoretical Maximum Diversion Requirement.............................................................5-7
5.2.6 Theoretical Irrigation Water Requirement……………………………………..5-8
5.2.7 Water Supply-Limited Consumptive Use of Crops…………………………….5-8
5.2.8 Livestock Consumptive Use…………………………………………………..5-10
5.3 MUNICIPAL AND DOMESTIC WATER USE……………………………………...5-10
5.3.1 Introduction…………………………………………………………………...5-10
5.3.2 Current Water Use…………………………………………………………….5-11
5.4 INDUSTRIAL WATER USE…………………………………………………………5-12
5.4.1 Introduction…………………………………………………………………...5-12
5.4.2 Current Water Use…………………………………………………………….5-13
5.5 RECREATIONAL WATER USE……………………………………………………..5-15
5.5.1 Introduction…………………………………………………………………...5-15
5.5.2 Current Water Uses…………………………………………………………...5-15
Fishing……………………………………………………………………………….5-15
Boating………………………………………………………………………………5-16
Waterfowl Hunting…………………………………………………………………..5-17
Skiing and Winter Sports…………………………………………………………….5-17
Golfing……………………………………………………………………………….5-17
Wyoming State Parks and Historical Sites…………………………………………..5-18
Wind River Indian Reservation (WRIR)……………………………………………..5-18
National Parks and Monuments……………………………………………………..5-18
National Forests……………………………………………………………………..5-19
Summary of Recreational Use……………………………………………………….5-19
5.6 ENVIRONMENTAL WATER USE………………………………………………….5-19
5.6.1 Introduction…………………………………………………………………...5-19
5.6.2 Current Water Use…………………………………………………………….5-20
Instream Flows………………………………………………………………………5-20
Reservoir Minimum Pools…………………………………………………………...5-21
Direct Wildlife Consumption………………………………………………………...5-21
Threatened and Endangered Species………………………………………………..5-21
Wetlands……………………………………………………………………………..5-22
5.7 EVAPORATION………………………………………………………………………5-23
5.8 REFERENCES………………………………………………………………………...5-23
6.0 PROJECTIONS………………………………………………………………………..6-1
6.1 FUTURE ECONOMIC AND DEMOGRAPHIC SCENARIOS……………………….6-1
6.1.1 Overview of Planning Scenarios……………………………………………….6-1
High Scenario…………………………………………………………………………6-1
Mid Scenario………………………………………………………………………….6-1
Low Scenario………………………………………………………………………….6-1
6.2 AGRICULTURAL DEMAND PROJECTIONS……………………………………….6-1
6.2.1 Introduction…………………………………………………………………….6-1
High Scenario…………………………………………………………………………6-2
Mid Scenario………………………………………………………………………….6-2
Low Scenario………………………………………………………………………….6-3
6.2.2 Future Water Needs and Demands……………………………………………..6-3
6.2.3 Tribal Futures Agricultural Projects……………………………………………6-5
Wind/Bighorn River Basin Task 3D Technical Memorandum, “Available Surface Water
Determination”……………………………………………………………………….6-5

6.2.4 Irrigable Lands………………………………………………………………….6-6
6.3 MUNICIPAL AND DOMESTIC DEMAND PROJECTIONS………………………...6-8
6.3.1 Introduction…………………………………………………………………….6-8
6.3.2 Population Projections………………………………………………………….6-8
Current and Projected Population Estimates………………………………………...6-8
WDAI Population Projections………………………………………………………...6-9
USCB Projections…………………………………………………………………….6-9
Historic Growth Projections.......................................................................................6-10
Economic Base Methodology…………………………………..................................6-10
6.3.3 Municipal and Domestic Use Projections…………………………………….6-10
6.4 INDUSTRIAL DEMAND PROJECTIONS…………………………………………..6-11
6.4.1 Future Coal-fired and Natural Gas-fired Electric Power Production…………6-12
High Scenario……………………………………………………………………….6-12
Mid Scenario………………………………………………………………………...6-13
Low Scenario………………………………………………………………………...6-15
6.4.2 Coal, Uranium, and Miscellaneous Mining…………………………………...6-15
Coal………………………………………………………………………………….6-15
Uranium……………………………………………………………………………..6-16
Miscellaneous Mining……………………………………………………………….6-16
6.4.3 Oil Production and Refining…………………………………………………..6-16
6.4.4 Coalbed Methane and Natural Gas Production……………………………….6-17
6.4.5 Coal Conversion Facilities……………………………………………………6-18
6.4.6 Soda Ash Production………………………………………………………….6-18
High Scenario………………………………………………………………………..6-19
Mid Scenario………………………………………………………………………...6-19
Low Scenario………………………………………………………………………...6-20
6.4.7 Miscellaneous Industry……………………………………………………….6-20
6.4.8 Industrial Summary…………………………………………………………...6-21
6.5 RECREATIONAL DEMAND PROJECTIONS………………………………………6-22
6.5.1 Introduction…………………………………………………………………...6-22
6.5.2 Future Recreation Demand……………………………………………………6-22
6.5.3 Adequacy of Existing Resources……………………………………………...6-24
6.6 ENVIRONMENTAL DEMAND PROJECTIONS……………………………………6-26
6.6.1 Instream Flows………………………………………………………………..6-26
6.6.2 Minimum Reservoir Pools…………………………………………………….6-26
6.6.3 Minimum Releases and Reservoir Bypasses………………………………….6-27
6.6.4 Wetlands and Wildlife Habitat………………………………………………..6-27
6.6.5 Direct Wildlife Consumption…………………………………………………6-28
6.7 SUMMARY OF FUTURE WATER DEMAND PROJECTIONS……………………6-28
6.8 REFERENCES………………………………………………………………………...6-30
7.0 AVAILABILITY………………………………………………………………………7-1
7.1 SURFACE WATER…………………………………………………………………….7-1
7.1.1 Introduction…………………………………………………………………….7-1
7.1.2 Methodology……………………………………………………………………7-1
7.1.3 Surface Water Model…………………………………………………………...7-2
Model Overview………………………………………………………………………7-2
Model Structure and Components…………………………………………………….7-3
Stream Gage Data…………………………………………………………………….7-3
Diversion Data………………………………………………………………………..7-3
Reach Gain/Loss……………………………………………………………………...7-4

7.1.4 Supply Estimates……………………………………………………………….7-4
7.1.5 Basin Supply Estimates………………………………………………………...7-6
Bear River Basin……………………………………………………………………...7-6
Green River Basin…………………………………………………………………….7-6
Northeast Wyoming River Basin……………………………………………………...7-6
Platte River Basin…………………………………………………………………….7-6
Powder/Tongue River Basin…………………………………………………………..7-6
Snake/Salt River Basins……………………………………………………………….7-7
Wind/Bighorn River Basins…………………………………………………………...7-7
7.1.6 Future Supply Estimates………………………………………………………..7-9
7.2 GOUNDWATER………………………………………………………………………..7-9
7.2.1 Background……………………………………………………………………..7-9
7.2.2 Diversion Rates……………………………………………………………….7-10
7.2.3 Groundwater in Storage……………………………………………………….7-10
7.2.4 Groundwater Recharge………………………………………………………..7-12
7.2.5 Groundwater Quality………………………………………………………….7-13
7.2.6 Basin Summaries……………………………………………………………...7-14
7.3 WATER CONSERVATION…………………………………………………………..7-15
7.3.1 Introduction…………………………………………………………………...7-15
7.3.2 Agricultural Water Conservation……………………………………………..7-16
7.3.3 Industrial Water Conservation………………………………………………...7-17
7.3.4 Municipal Water Conservation………………………………………………..7-17
7.3.5 Recreational and Environmental Water Conservation………………………..7-17
7.3.6 Conclusion…………………………………………………………………….7-18
7.4 REFERENCES………………………………………………………………………...7-18
8.0 OPPORTUNITIES…………………………………………………………………….8-1
8.1 INTRODUCTION………………………………………………………………………8-1
8.2 SCREENING CRITERIA FROM THE BASIN PLANS………………………………8-1
8.2.1 Long List of Future Water Use Opportunities………………………………….8-1
8.2.2 Short List of Future Water Use Opportunities…………………………………8-2
Water Availability…………………………………………………………………….8-2
Financial Feasibility………………………………………………………………….8-2
Public Acceptance…………………………………………………………………….8-2
Number of Sponsors/Beneficiaries/Participants……………………………………...8-2
Legal/Institutional Concerns………………………………………………………….8-2
Environmental/Recreational Benefits………………………………………………...8-2
8.2.3 Framework Scoring Matrix…………………………………………………….8-2
Monetary Factors……………………………………………………………………..8-3
Non-Monetary Factors………………………………………………………………..8-3
8.2.4 Agricultural Need………………………………………………………………8-3
8.2.5 Potential Groundwater Development…………………………………………..8-4
8.3 BEAR RIVER BASIN………………………………………………………………….8-4
8.3.1 Physically Available Flows…………………………………………………….8-4
8.3.2 Compact Limitations…………………………………………………………...8-4
8.3.3 Agricultural Needs……………………………………………………………...8-5
8.3.4 Long and Short Lists of Future Water Use Opportunities……………………..8-5
8.3.5 Central Division Investigations………………………………………………..8-5
8.3.6 Upper Division Investigations…………………………………………………8-5
8.3.7 Framework Scoring Matrix……………………………………………………8-6
8.3.8 Recommendations……………………………………………………………...8-6

Central Division………………………………………………………………………8-6
Upper Division………………………………………………………………………..8-6
8.3.9 Future Groundwater Development……………………………………………..8-8
8.4 GREEN RIVER BASIN………………………………………………………………...8-8
8.4.1 Physically Available Flows…………………………………………………….8-8
8.4.2 Compact Limitations…………………………………………………………...8-8
8.4.3 Agricultural Needs……………………………………………………………...8-8
8.4.4 Long List of Future Water Use Opportunities………………………………….8-9
8.4.5 Short List of Future Water Use Opportunities…………………………………8-9
8.4.6 Supplemental Studies…………………………………………………………8-12
Green River Ground Water Recharge and Alternative Storage, Level I Project……8-12
Middle Pine Reservoir Rehabilitation Level II Study..................................................8-12
Upper Green River Storage Study…………………………………………………...8-12
Little Snake River Dams Level II Studies……………………………………………8-13
8.4.7 Framework Scoring Matrix…………………………………………………...8-13
8.4.8 Recommendations for Storage Opportunities………………………………...8-15
Piney Creek Drainage and Tributaries……………………………………………...8-15
Sand Hill Off-Channel Reservoir……………………………………………………8-15
Middle Piney Reservoir Rehabilitation.......................................................................8-15
East Fork o the New Fork Drainage (Church Off-Channel Reservoir)……………..8-15
Hams Fork Drainage………………………………………………………………..8-15
Viva Naughton Enlargement………………………………………………………...8-15
Dempsey Basin Reservoir…………...………………………………………………8-15
Cottonwood Creek-Drainage (Mickelson Creek Off-Channel Reservoir)…………..8-16
Horse Creek Drainage (Horse Pasture Draw Off-Channel Reservoir)……………..8-16
Beaver Creek Drainage (Cow Gulch Off-Channel Reservoir)……………………...8-16
8.4.9 Future Groundwater Development……………………………………………8-16
8.5 NORTHEAST WYOMING RIVER BASIN………………………………………….8-17
8.5.1 Physically Available Flows…………………………………………………...8-17
8.5.2 Compact Limitations………………………………………………………….8-17
8.5.3 Agricultural Need……………………………………………………………..8-18
8.5.4 Long List of Future Water Use Opportunities………………………………...8-19
8.5.5 Short List of Future Water Use Opportunities………………………………..8-19
8.5.6 Crook County Reservoir Studies……………………………………………...8-22
Crook County Reservoirs and Water Management Study Level I…………………...8-22
Crook County Reservoir Project-Level I…………………………………………….8-22
Stockade Beaver Creek Reservoir-Level I…………………………………………...8-22
Beaver Creek Dam and Reservoir-Level I…………………………………………..8-22
Beaver Creek Dam and Reservoir Project…………………………………………..8-22
8.5.7 Framework Scoring Matrix…………………………………………………...8-23
8.5.8 Recommendations fro Future Storage Opportunities…………………………8-26
Belle Fourche River Basin…………………………………………………………..8-26
Upper or Lower Inyan Kara Reservoir Sites………………………………………..8-26
Smaller Reservoirs…………………………………………………………………..8-26
Beaver Creek Basin.....................................................................................................8-26
Cheyenne River Basin……………………………………………………………….8-27
8.5.9 Future Groundwater Development……………………………………………8-27
8.5.10 Coal Bed Methane Waters…………………………………………………….8-27
8.6 PLATTE RIVER BASIN……………………………………………………………...8-27
8.6.1 Physically Available Flows…………………………………………………...8-27
8.6.2 Institutional Limitations………………………………………………………8-27

8.6.3 Needs …………………………………………………………………………8-27
8.6.4 Long List of Future Water Use Opportunities………………………………...8-29
8.6.5 Revised Short List of Future Water Use Opportunities……………………….8-29
8.6.6 Structural Future Water Use Opportunities…………………………………...8-30
Coalbed Methane Waters……………………………………………………………8-30
Groundwater Augmentation........................................................................................8-30
Improving Agricultural Irrigation Systems and Control Efficiencies……………….8-30
Modifications of Pathfinder Dam and Reservoir……………………………………8-31
Regionalization of Public Water Supply Systems……………………………………8-31
Reuse Alternatives…………………………………………………………………...8-31
Snow Fences…………………………………………………………………………8-31
Transbasin Diversions……………………………………………………………….8-31
Water Diversions from Wyoming’s Green River Basin (WWDC)…………………...8-32
Wind River Export Study-Level I (ECI, 2002)……………………………………...8-32
Upper Laramie River RE-regulations Opportunities………………………………..8-32
8.6.7 Non-Structural Future Water Use Opportunities……………………………...8-32
Drought Response Planning…………………………………………………………8-32
Enhanced Recreational Use of Water Reservoirs…………………………………...8-33
Glendo Reservoir…………………………………………………………………….8-33
Increasing Runoff From National Forests…………………………………………..8-33
Multipurpose Flood Control Programs……………………………………………..8-33
Water Banking……………………………………………………………………….8-33
Water Conservation………………………………………………………………….8-33
Water Exchanges…………………………………………………………………….8-33
Water Right Transfers……………………………………………………………….8-34
Weather Modification………………………………………………………………..8-34
8.7 POWDER/TONGUE RIVER BASINS………………………………………………..8-34
8.7.1 Physically Available Flow…………………………………………………….8-34
8.7.2 Compact Limitations………………………………………………………….8-34
8.7.3 Agricultural Needs…………………………………………………………….8-35
8.7.4 Long List of Future Water Use Opportunities………………………………..8-36
8.7.5 Short List of Future Water Use Opportunities………………………………..8-36
8.7.6 Recommendations for Storage Opportunities………………………………...8-43
Little Bighorn River Basin…………………………………………………………...8-43
Tongue River Basin ....................................................................................................8-43
Clear Creek Basin…………………………………………………………………...8-43
Crazy Woman Creek Basin………………………………………………………….8-43
Powder River Basin………………………………………………………………….8-44
Little Powder River Basin…………………………………………………………...8-44
8.7.7 Future Groundwater Development……………………………………………8-44
8.7.8 Coal Bed Methane Waters…………………………………………………….8-44
8.8 SNAKE/SALT RIVER BASIN………………………………………………………..8-44
8.8.1 Physically Available Flows…………………………………………………...8-44
8.8.2 Compact Limitations………………………………………………………….8-45
8.8.3 Agricultural Needs…………………………………………………………….8-45
8.8.4 Long List of Future Use Opportunities……………………………………….8-45
8.8.5 Short Lists of Future Water Use Opportunities……………………………….8-45
Agricultural Opportunities…………………………………………………………..8-48
Domestic/Municipal Opportunities………………………………………………….8-48
Environmental Opportunities………………………………………………………..8-48
Recreational Opportunities………………………………………………………….8-48

Industrial Opportunities……………………………………………………………..8-48
8.8.6 Recommendations for Opportunities………………………………………….8-48
Salt River Sub-Basin………………………………………………………………...8-48
Snake River Sub-Basin………………………………………………………………8-49
8.8.7 Future Groundwater Development……………………………………………8-49
8.9 WIND/BIGHORN RIVER BASINS…………………………………………………..8-50
8.9.1 Physically Available Flows……………………………………..……………8-50
8.9.2 Compact Limitations………………………………………………………….8-50
8.9.3 Agricultural Needs……………………………………………………………8-50
8.9.4 Long List of Future Water Use Opportunities………………………...……...8-51
8.9.5 Short List of Future Water Use Opportunities………………………………..8-51
8.9.6 Supplemental Storage Studies………………………………………………...8-55
Upper Wind River Storage Project-Level I Study…………………………………...8-55
Popo Agie River Watershed Study-Level I Study……………………………………8-55
Crowheart Area/Dinwoody Canal System-Level I Study……………………………8-55
Kirby Area Water Supply-Level I Study……………………………………………..8-55
Cottonwood/Grass Creek Watershed Management Plan-Level I Study…………….8-56
Owl Creek Master Plan……………………………………………………………...8-56
Wind River Export Study-Level I…………………………………………………….8-56
8.9.7 Framework Scoring Matrix…………………………………………………...8-56
8.9.8 Recommendations for Storage Opportunities………………………………...8-58
Upper Wind River ......................................................................................................8-58
Little Wind River…………………………………………………………………….8-58
Clarks Fork………………………………………………………………………….8-59
Bighorn River………………………………………………………………………..8-59
Greybull River.............................................................................................................8-59
Shoshone River………………………………………………………………………8-59
Owl Creek……………………………………………………………………………8-59
8.9.9 Future Groundwater Development……………………………………………8-59
8.10 REFERENCES………………………………………………………………………...8-60
9.0 PROJECT FUNDING…………………………………………………………………9-1
9.1 INTRODUCTIONS……………………………………………………………………..9-1
9.2 FUNDING OF WATER DEVELOPMENT PROJECTS………………………………9-1
9.2.1 Federal Programs……………………………………………………………….9-2
U.S. Department of Agriculture Rural Development Programs……………………...9-2
Natural Resources Conservation Service……………………………………………..9-2
9.2.2 State Programs………………………………………………………………….9-2
Wyoming Water Development Commission…………………………………………..9-2
Wyoming Department of Environmental Quality……………………………………..9-3
State Land and Investment Board…………………………………………………….9-3
GLOSSARY…………………………………………………………………………………GA-1
ACRONYM LIST……………………………………………………………………………GA-6

List of Tables
Table 1-1 Basin Plan Summary…………………………………………………………….. 1-3
Table 3-1 Landownership and Area………………………………………........................... 3-2
Table 3-2 Population 1950 to 2000……………………………………………………........ 3-5
Table 3-3 Basin Area Populations…………………………………………………………. .3-6
Table 3-4 Age Cohorts by Percentage…………………………………………................... 3-6
Table 3-5 2004 Population Characteristics………………………………………………… 3-8
Table 3-6 Farm and Farm-Related Employment, 2002……………………………………. 3-9
Table 3-7 Electric Power Generating Facilities…………………………………………... 3-11
Table 3-8 WDEQ Groundwater Quality Standards………………………......................... 3-27
Table 3-9 Drinking Water Standards……………………………………………………... 3-28
Table 4-1 Total Annual Flow……………………………………………….......................... 4-2
Table 4-2 Recommended Guidelines for TDS in Irrigation Water………………………… 4-4
Table 5-1 Irrigated Acreage……………………………………………………................... 5-3
Table 5-2 1973 Versus Current Active Crop Distribution…………………………………. 5-4
Table 5-3 Estimated Average Annual Surface Water Diversions…………......................... 5-7
Table 5-4 Estimated Average Annual Irrigation Water Requirement…………........……... 5-9
Table 5-5 Estimated Average Annual Water Supply-Limited Consumptive Use
(Depletions)……………………………………………………………………… 5-9
Table 5-6 Municipal and Domestic Use…………………………………………….……. 5-11
Table 5-7 Municipal and Domestic Water Depletions……………………........................ 5-12
Table 5-8 Annual Industrial Water Use………………………………………………….. 5-14
Table 5-9 Angler Days……………………………………………………......................... 5-16
Table 5-10 Visitation to National Parks and National Monuments………......................... 5-19
Table 6-1 Presently Irrigated Acreage and Projected Irrigation Development….................. 6-4
Table 6-2 Current and Projected Irrigation Diversions…………………………………….. 6-4
Table 6-3 Current and Projected Consumptive Irrigation Use……………………………... 6-5
Table 6-4 Tribal Futures Projects…………………………………………………………... 6-6
Table 6-5 Summary of Potentially Irrigable Lands Within the Wind/Bighorn Basin ……... 6-7
Table 6-6 Livestock Consumptive Use…………………………………………………...... 6-8
Table 6-7 Actual and Projected Populations……………………………………………. … 6-9
Table 6-8 Projected Municipal and Domestic Water Use………………………………. .. 6-11
Table 6-9 Projected Electrical Generation Water Needs………………………………... . 6-14
Table 6-10 Total Industrial Water Demand Projections………………………………… . 6-22
Table 6-11 Projected Annual Growth Rates: Population and Tourism………………… . 6-23
Table 6-12 Current and Projected Water-Based Recreational Activity Days……………. 6-24
Table 6-13 Current and Projected Water Consumption for Golf and Skiing…………….. 6-24
Table 6-14 Projected Annual Total Consumptive Water Demands……………………… 6-29
Table 6-15 Summary of Current and Projected Future Water Uses……………….…..………6-30
Table 7-1 Average Annual Streamflow and Uses- Normal Condition……………………... 7-5
Table 7-2 Available Flows…………………………………………………………………. 7-8
Table 7-3 Average Annual Streamflow and Uses – Midlevel Development – Dry
Condition……………………………………………………………………... 7-9
Table 7-4 Groundwater Availability Summary…………………………………………... 7-14
Table 7-5 Groundwater Permits Summary……………………………………………….. 7-15
Table 8-1 Agricultural Needs, Bear River Basin…………………………………………... 8-5
Table 8-2 Framework Scoring Matrix, Bear River Basin………………………………….. 8-7
Table 8-3 Framework Section Scoring, Nonmonetary Factors, Bear River Basin………… 8-7
Table 8-4 Agricultural Needs, Green River Basin Tributaries……………………………... 8-9

Table 8-5 Evaluated Short-List: Green River Basin…………………………………........ 8-10
Table 8-6 Framework Scoring Matrix, Green River Basin……………………………….. 8-13
Table 8-7 Framework Selection Scoring, Nonmonetary Factors, Green River Basin……. 8-14
Table 8-8 Apportionment of Available Flow Per Belle Fourche River Compact………… 8-18
Table 8-9 Agricultural Needs, Northeast Wyoming River Basin………………………… 8-18
Table 8-10 Evaluated Short List: Belle Fourche River Basin……………………………. 8-20
Table 8-11 Evaluated Short List: Cheyenne River Basin…………………………………8-21
Table 8-12 Framework Scoring Matrix, Northeast Wyoming River Basin Storage
Opportunities………………………………………………………………… 8-24
Table 8-13 Secondary Selection Scoring, Nonmonetary Factors, Northeast Wyoming
River Basin Storage Opportunities…………………………………………… 8-13
Table 8-14 Future Needs, Platte River Basin…………………………………………….. 8-28
Table 8-15 Remaining Allocation of Available Flow per Yellowstone River Compact… 8-35
Table 8-16 Agricultural Needs, Platte River Basin……………………………………….. 8-35
Table 8-17 Evaluated Short List: Little Bighorn River Basin………………………….. ..8-37
Table 8-18 Evaluated Short List: Tongue River Basin…………………………………... 8-38
Table 8-19 Evaluated Short List: Clear Creek Basin……………………………………. .8-39
Table 8-20 Evaluated Short List: Crazy Woman Creek Basin…………………………... 8-40
Table 8-21 Evaluated Short List: Powder River Basin…………………………………... 8-41
Table 8-22 Evaluated Short List: Little Powder River Basin……………………………. 8-42
Table 8-23 Irrigated Acreage, Snake/Salt River Basin…………………………………… 8-45
Table 8-24 Available Flows, Snake/Salt River Basin…………………………………….. 8-45
Table 8-25 Evaluated Short List: Salt River Basin………………………………………. 8-46
Table 8-26 Evaluated Short List: Snake River Basin……………………………………. 8-47
Table 8-27 Agricultural Needs, Wind/Bighorn River Basin……………………………… 8-51
Table 8-28 Short List of Future Projects, Wind/Bighorn River Basin……………………. 8-52
Table 8-29 Evaluated Short List: Wind/Bighorn River Basin…………………………… 8-53
Table 8-30 Framework Scoring Matrix, Wind/Bighorn River Basin…………………….. 8-57
Table 8-31 Framework Selection Scoring, Nonmonetary Factors, Wind/Bighorn River
Basin..…………………………………………………………………………8-57

List of Figures
Figure 2-1 Snapshot of P-Tool…………………………………………………………….. 2-2
Figure 3-1 Water Resource Regions………………………………………………………3-32
Figure 3-2 River Basin Planning Area Map……………………………………………… 3-33
Figure 3-3 Landownership by River Basin………………………………………………. 3-34
Figure 3-4 Shaded Relief Map…………………………………………………………… 3-35
Figure 3-5 Average Number of Frost-Free Days………………………………………… 3-36
Figure 3-6 Average Seasonal Consumptive Irrigation Requirements for
Grass (In Inches)………………………………………………………………3-37
Figure 3-7 Wyoming River Basin Compacts and Decrees………………………………. 3-38
Figure 4-1 Mean Annual Precipitation, 1071-2000……………………………………… 4-11
Figure 4-2 Mean Annual Potential Evapotranspiration………………………….............. 4-12
Figure 4-3 USGS Stream Flow Gage Locations…………………………………………. 4-13
Figure 4-4 Average Annual Streamflow…………………………………………………. 4-14
Figure 4-5a Monthly Streamflow Variation……………………………………………… 4-15
Figure 4-5b Annual Streamflow Variation………………………………………………... 4-16
Figure 4-6
Figure 4-7
2006 303(d) Waters with Water Quality Impairments………………..............4-17
Potentiometric Surface of the Tensleep Aquifer in the Bighorn Basin,
Wyoming……………………………………………………………………... 4-18
Figure 4-8 Example: Wyoming Groundwater Hydrograph……………………………... 4-19
Figure 4-9 Wyoming Hydrogeology Map………………………………………………... 4-20
Figure 4-10 Active Wells………………………………………………………………….. 4-21
Figure 4-11 Aquifer Sensitivity……………………………………………………............ 4-22
Figure 4-12 Active CBM Wells……………………………………………………............ 4-23
Figure 5-1 Irrigated Lands……………………………………………………………….. 5-24
Figure 5-2 Active Irrigation Wells……………………………………………………….. 5-25
Figure 5-3 Municipalities and Source of Supply………………………………………… 5-26
Figure 5-4 Municipal Wells……………………………………………………………… 5-27
Figure 5-5 Domestic Wells………………………………………………………………. 5-28
Figure 5-6 Industrial and Miscellaneous Wells………………………………………….. 5-29
Figure 5-7 Ski Areas and Golf Courses………………………………………………….. 5-30
Figure 5-8 State Parks and Historic Sites………………………………………………… 5-31
Figure 5-9 National Parks, Forests, and Monuments…………………………………….. 5-32
Figure 5-10 Instream Flow Segments………………………………………………........... 5-33
Figure 5-11 Selected Reservoirs Greater than 1000 ac-ft. …………………………........... 5-34
Figure 6-1 Tribal Futures Projects and Irrigable Lands………………………………….. 6-31
Figure 6-2 Permitted Coalbed Methane Wells as of December 31, 2004………….......... 6-32
Figure 6-3 Coalbed Methane Wells & Production in the Powder River Coal Field.......... 6-33
Figure 6-4 Coalbed Methane Gas & Water Production………………………………….. 6-34
Figure 6-5 Projected Recoverable Coalbed Methane…………………………………….. 6-35
Figure 7-1 Bear River Basin Available Flows…………………………………………… 7-19
Figure 7-2 Green River Basin, Upper Green Available Flows……………………........... 7-20
Figure 7-3 Green River Basin, Little Snake River Available Flows……………………... 7-21
Figure 7-4 Northeast River Basin Available Flows……………………………………… 7-22
Figure 7-5 Powder/Tongue River Basin Available Flows……………………………….. 7-23
Figure 7-6 Snake/Salt River Basin Available Flows…………………………………….. 7-24
Figure 7-7 Wind/Bighorn River Basin Available Flows…………………………………. 7-25
Figure 7-8 Groundwater Control Areas………………………………………………….. 7-26
Figure 8-1 Bear River Basin Potential Site……………………………………………….8-61

Figure 8-2 Green River Basin, Upper Green Potential Reservoir Sites………………….. 8-62
Figure 8-3 Green River Basin, Little Snake River Potential Reservoir Sites……………. 8-63
Figure 8-4 Northeast River Basin Potential Reservoir Sites………………………........... 8-64
Figure 8-5 Powder River/Tongue River Basin Potential Reservoir Sites…………........... 8-65
Figure 8-6 Snake/Salt River Basin Potential Reservoir Sites……………………………. 8-66
Figure 8-7 Wind/Bighorn River Basin Potential Reservoir Sites…………………........... 8-67

1.0 INTRODUCTION
1.1 OVERVIEW
This Wyoming Framework Water Plan presents
a statewide perspective on water resources, compiled
from the results of a seven-basin planning process
performed by the Wyoming Water Development
Commission (WWDC). This Framework Water Plan
presents summary information on:
! The Setting chapter presents basic physical
information about Wyoming, current
economic and social conditions, and an
outline of the institutional constraints on
water use.
! The Resources chapter characterizes Wyoming’s total water supply, including information
on where the resources are located and their quality.
! The Use chapter quantifies how Wyoming is using its water resources in both the depleting
and non-depleting water use sectors.
! The Projections chapter provides estimates of the future water needs of the state, for the
depleting and non-depleting water use sectors.
! The Availability chapter presents estimates of the amounts and locations of unused water
resources that are available to meet needs. Unused water resources are those that are
physically and legally available over and above existing uses.
! Finally, the Opportunities chapter summarizes information regarding opportunities for
meeting the projected water needs of Wyoming. These opportunities may provide a starting
point for existing and future water users seeking to address water supply deficits.
In addition to presenting information on water resources of the state, this document covers two
other important subjects:
! A Web-based Presentation Tool is described in Chapter 2. This tool makes the results of
this Framework Water Plan available online and provides a structure that will promote
efficient future planning updates.
! Project Funding is presented in Chapter 9. This chapter outlines opportunities for project
proponents to obtain state and federal funding assistance.
1-1

1.0 INTRODUCTION
1.2 NEED FOR BASIN PLANNING AND FRAMEWORK PLAN
The Wyoming water planning process is founded on the Prior Appropriation Doctrine and the
understanding that the State of Wyoming should manage its water resources “for the benefit of the
citizens of the state.” The WWDC was created by the 1979 Wyoming Legislature and is charged with
responsibility for “...the planning, selection, financing, construction, acquisition, and operation of projects
and facilities for the conservation, storage, distribution and use of water, necessary in the public interest
to develop and preserve Wyoming's water and related land resources.”
The major planning goals of the Water Development Commission include:
! Basinwide Plans – These plans should be generated for
each of the state’s major drainage basins. The plans’
purpose is, in part, to quantify existing uses and to
project future needs. The plans should also serve to
identify and prioritize water development opportunities.
The plans shall document the State’s plan to utilize its
compact and decree allocations.
! Project Planning – The program should assist Wyoming
municipalities, irrigation districts, and other public entities’ efforts to plan for the future.
This assistance will typically come through the development of reconnaissance and
feasibility-level studies, which serve to identify water supply requirements and prioritize
water system improvements.
! Federal Funding – Presently, there are federal programs which provide funding assistance
for some types of water development projects. However, in order to access these funds,
costly feasibility/environmental studies are often needed. The WWDC shall consider
participating in these studies if a proposed project alleviates a water development,
management, or rehabilitation problem, or allows the continued beneficial use of water. The
amount of the WWDC’s financial participation shall be based on the proponent’s ability to
pay.
! Research – The program should continue its participation in research projects which serve to
clarify economic, environmental, water development, and management issues.
! Coordination – The WWDC should strive to keep informed on proposed state and federal
rules and regulations that may affect water use, development, and management.
The last statewide water planning process was completed in 1973 with the publication of the
Wyoming Framework Water Plan. As with the current planning process, the process in the 1970s was
performed on a basin-by-basin basis to capture the unique water situation and needs in each basin. Since
1973, technological advances have been made in water resource planning, and political and regulatory
conditions in water resource management have changed. Therefore, it was necessary that Wyoming
complete an updated statewide water planning report.
1-2

1.0 INTRODUCTION
1.3 BASIN PLANS
Most information in this Framework Water Plan was collected and presented in the development
of seven individual river basin plans. These basin plans were prepared by the WWDC and its consultants
between 2001 and 2006 as shown in Table 1-1. The executive summary of these individual planning
efforts is included in Volume II of this report.
Table 1-1 Basin Plan Summary
Basin Plan Consultant Date Completed
Green River
States West Water Resources Corporation
Boyle Engineering, Inc.
Purcell Consulting, P.C.
February 2001
Water Rights Services, L.L.C.
Watts and Associates, Inc.
Bear River
Forsgren Associates Inc.
Anderson Consulting Engineers, Inc.
Leonard Rice Engineers, Inc.
September 2001
BBC Research & Consulting
Northeast Wyoming Rivers
HKM Engineering Inc.
Lord Consulting
February 2002
Watts and Associates, Inc.
Powder/Tongue Rivers
HKM Engineering Inc.
Lord Consulting
February 2002
Watts and Associates, Inc.
Snake/Salt Rivers
Sunrise Engineering, Inc.
Boyle Engineering, Inc.
Hinckley Consulting
BBC Consulting, Inc.
June 2003
Fassett Consulting
Nelson Engineering, Inc.
Rendezvous Engineering, Inc.
Wind/Bighorn Rivers
BRS, Inc.
MWH
Lidstone and Associates
Trihydro Corporation
October 2003
Donnell and Allred Inc.
Water Rights Services, L.L.C.
Platte River
Trihydro Corporation
Lidstone and Associates
Harvey Economics
May 2006
Water Rights Services, L.L.C.
1-3

2.0 WEB TOOL
The Wyoming Water Framework Water Plan is available on the World Wide Web. A PDF
version and GIS products can be downloaded at http://waterplan.state.wy.us/frameworkplan.html. An
interactive Presentation Tool is available at http://waterplan.wrds.uwyo.edu/fwp/.
Figure 2-1 shows an example page from the Presentation Tool. The Presentation Tool features:
! Powerful Searching
! Database Driven Tables
! Downloadable Maps and Figures
2.1 Searching
Google searching is available on each page and defaults to search the Water Plan site only. After
your first set of search results are presented, you will then have the option to search the entire web in
addition to just the Water Plan site. Each search will return up to 8 results, with the option to select
"More results" if there are more than 8 matches returned. When you select "More results", you will go
into the main Google search site.
2.2 Database Tables
All of the data presented in tables represents values from the 2007 Framework Water Plan. Many
of these tables will be updated over time. These tables have a hyperlink at the bottom: Click here to
check for more recent data..
This link will open the table in a new window. The values in the table will represent the most
recent data available in the database. Where data exist that are more recent than the 2007 Framework
Water Plan, those data will be identified in red and the date and source of the data will be shown. The
data shown in the tables in this document will always show the 2007 Framework Water Plan values.
Only by clicking the hyperlink will updated values be displayed.
2.3 Maps and Figures
High resolution PDFs are available for all of the maps
and figures. Viewing or printing the PDFs requires the Adobe
Acrobat PDF viewer which is available for free download at
www.adobe.com/products/acrobat/readstep2.html.
Many of the PDF maps use layers, which can be turned
on and off individually. This feature aids the visualization of the
information being presented. The layered PDFs will have a
"Layers" tab near the upper left side of the window. Layers may
be turned on or off by clicking the eye icon left of the layer
name. In the example to the right, the "Roads" layer is turned
off, and is not now displayed on the map.
The layer feature requires Adobe Acrobat version 6 or greater. Acrobat 4, and possibly earlier
versions, will display the PDF, but without the ability to turn individual layers on and off.
2-1

2.0 WEB TOOL
Figure 2-1. Snapshot of P-Tool
2-2

3.0 SETTING
3.1 PHYSICAL SETTING
Wyoming’s geographic location, human
resources, physical characteristics, and natural
resources make up the setting of the Wyoming
Framework Water Plan. Wyoming straddles the
Continental Divide and provides the headwaters of
four major river basins of the West: the Missouri, the
Colorado, the Great Basin, and the Columbia. Figure
3-1 shows Wyoming’s relationship to the West’s
major river basins. The state contains 23 counties and
encompasses 98,210 square miles, making it the ninth
largest of the contiguous United States. Figure 3-2
shows a map of the state including the river basin
planning areas and the Continental Divide. Wyoming’s 493,782 people in 2000 rank the state fiftieth in
population. Its abundant natural resources rank Wyoming high in the production of minerals and energy
resources. Much of Wyoming’s heritage stems from its agricultural and livestock industry.
Transportation, important in the settlement of the state, combined with the scenic beauty of open spaces,
rugged mountains, forests, and national parks, enhances an important and growing tourist industry.
3.1.1 Land Area and Ownership
The land area within the boundaries of Wyoming is 62,854,000 acres, and the surface water area
is 456,000 acres. Of the land acreage, about 48 percent is owned by the federal government, 43 percent is
owned by private interests, 6 percent is owned by state and local government, and about 3 percent is
owned by the Eastern Shoshone and Northern Arapaho Tribes. Table 3-1 summarizes the landownership
on a statewide basis.
3-1

3.0 SETTING
Table 3-1 Landownership and Area
Landowners Acres Square Miles
UNITED STATES GOVERNMENT
National Park Service 2,343,000 4,000
Forest Service 9,233,000 14,000
Fish and Wildlife Service 47,000 70
Bureau of Land Management 17,470,000 27,000
Bureau of Reclamation 955,000 1,000
Total Federal 30,048,000 46,070
WYOMING
Land Commission 3,541,000 6,000
Recreation Commission 8,000 10
Game and Fish Department 165,000 260
Total State 3,714,000 6,270
LOCAL GOVERNMENT
Counties 22,000 30
Cities 48,000 80
School Districts and Colleges 24,000 40
Total Local Government 94,000 150
OTHER
Other Public Lands 1,987,000 3,000
Surface Water 456,000 710
Total Public 35,843,000 55,000
Total Private 27,011,000 42,000
TOTAL AREA 62,854,000 98,210
Source: University of Wyoming, Department of Geography & Recreation
Private
Federal
Surface Water
Other Public
Lands
State
Local
Government
3-2

3.0 SETTING
The 1973 Framework Water Plan reported that agricultural activities were using about 84 percent
of Wyoming’s land area. Currently agricultural activities probably use slightly less than 84 percent of
Wyoming’s land area due to municipal and industrial growth.
The percentage of privately owned land versus publicly owned land diminishes westward across
the state. Figure 3-3 shows the landownership by river basin planning area.
3.1.2 Physiography
Figure 3-4 shows the varied physiography of the state. Beginning near the center of Wyoming’s
southern boundary, the Continental Divide extends through Wyoming in a northwesterly direction,
separating the Missouri River drainage from the Columbia River and the Colorado River drainages. In
southcentral Wyoming, the Continental Divide splits to encircle a closed drainage basin, the Great Divide
Basin.
Topography
The mean elevation of Wyoming is about 6,700 feet, making the state the second highest in the
United States (only Colorado has a higher mean elevation). The topographic elevations vary from a
maximum of 13,804 feet above sea level at Gannett Peak in the Wind River Range to about 3,099 feet
above sea level in northeastern Wyoming where the Belle Fourche River flows into South Dakota.
Wyoming’s mountain ranges are generally oriented in a southeast to northwest trend. The Teton
Range is probably Wyoming’s most spectacular mountain range in that it rises abruptly from the floor of
Jackson Hole to elevations of 9,000 to over 13,500 feet above sea level. This is a rise from 3,000 feet to
over 7,000 vertical feet.
The topographic basins of the state contain a wide variety of geologic features including narrow
terraces, plains, rolling hills, badlands, deserts, and uplifts with foothills and steep mountain slopes near
most of the mountain ranges. Many areas of the state are dotted with sandstone buttes, hogbacks, and
breaks.
Drainage System
Most of the streams that originate in the mountainous areas are perennial streams deriving their
flow from snowmelt, rainfall runoff, and groundwater. The perennial streams provide most of the water
yield in the state; however, there are numerous intermittent streams that originate in the lower elevations
of the river basins.
Most of the water flowing through the state originates within the state’s boundaries, with the
following few exceptions. Colorado’s mountains contribute to Wyoming’s streamflow via the North
Platte, Laramie, and Little Snake Rivers. Montana contributes streamflow in the Clarks Fork River. The
headwaters of the Blacks Fork, Henrys Fork, and Bear River are in Utah.
About 72 percent of the land area of Wyoming drains northward and eastward into the Missouri
River system. Tributaries of the Colorado River drain about 17 percent of Wyoming. The Bear River
meanders along the western border of Wyoming and ends in Great Salt Lake in the Great Basin. The
Snake River starts in Wyoming and is tributary to the Columbia River. The Bear and Snake Rivers drain
about 7 percent of the state’s land area. The remaining 4 percent is in the closed Great Divide Basin.
3-3

3.0 SETTING
3.1.3 Climate
Wyoming’s climate is a product of its latitude, elevation,
and topography. The state is in the latitude of the prevailing
westerly winds with a dominance of maritime Pacific air. This
air is modified by the several mountain ranges between
Wyoming and the West Coast which cause low-level moisture to
be precipitated before reaching the state. Moisture in the higher
mountains ranges from 20 to over 40 inches per year, most of
which falls as snow. The eastern plains areas of the state
normally receive from 9 to 16 inches of precipitation annually,
most of which occurs between April and July. The desertic basins in the western part of the state
normally receive only 6 to 9 inches of precipitation annually.
Wyoming has large seasonal and daily temperature ranges. Temperatures higher than 110° F and
lower than -50° F have been recorded, and daily temperature changes of 40° F and more are not unusual.
An important climate indicator is the growing season. For some crops, the growing season is the
period between the last spring frost (occurrence of 32° F or lower) and the first fall frost. For forage
crops, the growing season is the period when the mean daily temperature is above 40° F. The average 32°
F freeze-free periods for Wyoming are shown on Figure 3-5. In areas with long growing seasons such as
the lower North Platte River area, other parts of eastern Wyoming, and the lower Bighorn River area,
high-value crops such as corn, sugar beets, and potatoes can be grown if irrigation water is available. In
areas with shorter growing seasons, the predominant crops are forage crops, alfalfa, and small grains. In
practically all areas of the state, irrigation is necessary for dependable crop production. The average
seasonal consumptive irrigation requirement (water needs minus effective precipitation) for grass is
shown in Figure 3-6.
3.2 SOCIOECONOMIC SETTING
3.2.1 Historic Population Growth
Almost all demographic data are compiled on the basis of political units such as state, cities, and
counties, and most of the economic data are reported on at the county, state, or national level.
According to the 2000 U.S. census, the population of Wyoming was 493,782 people, an increase
from 332,416 people in 1970. The 493,782 people resided in 193,608 households within Wyoming.
Roughly 45 percent of the state population lived in the Platte River Basin.
Wyoming’s population has been increasing fairly steadily over time. U.S. Census Bureau data
show that Wyoming’s population has been increasing since the 1870 census through the 2000 census with
one exception: during the 1980-1990 Energy Bust when state population actually dropped. Population
has since rebounded and is once again on the rise. Table 3-2 shows the population trend of Wyoming
over the past 50 years. Individual counties have experienced some fairly dramatic changes in population
over the past 50 years: e.g., Campbell County went from 4,839 persons in 1950 to 33,698 in 2000 while
Niobrara County went from 4,701 persons in 1950 to 2,407 in 2000.
3-4

3.0 SETTING
Table 3-2 Population 1950 to 2000
County 1950 1960 1970 1980 1990 2000
Albany 19,055 21,290 26,431 29,062 30,797 32,014
Big Horn 13,176 11,898 10,202 11,896 10,525 11,461
Campbell 4,839 5,861 12,957 24,367 29,370 33,698
Carbon 15,742 14,937 13,354 21,896 16,659 15,639
Converse 5,933 6,366 5,938 14,069 11,128 12,052
Crook 4,738 4,691 4,535 5,308 5,294 5,887
Fremont 19,580 26,168 28,352 38,992 33,662 35,804
Goshen 12,634 11,941 10,885 12,040 12,373 12,538
Hot Springs 5,250 6,365 4,952 5,710 4,809 4,882
Johnson 4,707 5,475 5,587 6,700 6,145 7,075
Laramie 47,662 60,149 56,360 68,649 73,142 81,607
Lincoln 9,023 9,018 8,640 12,177 12,625 14,573
Natrona 31,437 49,623 51,264 71,856 61,226 66,533
Niobrara 4,701 3,750 2,924 2,924 2,499 2,407
Park 15,182 16,874 17,752 21,639 23,178 25,786
Platte 7,925 7,195 6,486 11,975 8,145 8,807
Sheridan 20,185 18,989 17,852 25,048 23,562 26,560
Sublette 2,481 3,778 3,755 4,548 4,843 5,920
Sweetwater 22,017 17,920 18,391 41,723 38,823 37,613
Teton 2,593 3,062 4,823 9,355 11,172 18,251
Unita 7,331 7,484 7,100 13,021 18,705 19,742
Washakie 7,252 8,883 7,569 9,496 8,388 8,289
Weston 6,733 7,929 6,307 7,106 6,518 6,644
Yellowstone
Park 353 420 See Note 1
WYOMING 290,529 330,066 332,416 469,557 453,588 493,782
1 Yellowstone Park is included in Teton and Park Counties
Source: Equality State Almanac 2006 State of Wyoming
The 2000 census data were broken out into the river basin planning areas by the Wyoming
Department of Administration and Information (WDAI) Economic Research Division. Table 3-3 presents
the population estimates for each of the river basin planning areas for 2000 and 2005. The 2005
population estimates are based on U.S. Census Bureau estimates for the state of Wyoming and for each of
the counties. Rapid changes in population are again evident; these changes are often associated with or
tied to changes in the energy and minerals sectors.
3-5

3.0 SETTING
Table 3-3 Basin Area Populations
River Basin 2000 Population 2005 Population
Bear 14,550 14,530
Green 54,760 56,229
Northeast Wyoming 45,600 49,034
Platte 227,330 232,976
Powder/Tongue 38,420 40,069
Snake/Salt 27,480 29,601
Wind/Bighorn 86,050 86,854
WYOMING TOTAL 1 494,190 509,293
Source: Wyoming Department of Administration and Information, Economic
Research Division
1
Individual basin numbers do not total to 493,782 the 2000 census population due
to differences experienced in disaggregation and assignment of census block data
to the river basin areas.
3.2.2 Aging Population
In 2000, there was a variation in age distributions for the counties in Wyoming. Albany,
Campbell, Sweetwater, Teton, and Uinta Counties had a more youthful population. Goshen, Hot Springs,
Johnson, and Niobrara Counties had an older population, with a greater percentage of residents over the
age of 55. Table 3-4 provides a comparison of age cohorts by percentage for the U.S., Wyoming, and the
counties.
Table 3-4 Age Groups by Percentage
Age Group
Location 0 -19 20 - 34 35 - 54 55 - 64 65 & Older
U.S. 29 21 29 9 12
Wyoming 30 19 31 9 12
Albany 26 35 24 7 8
Big Horn 28 16 26 13 17
Campbell 30 21 34 9 6
Carbon 27 17 33 10 12
Converse 31 16 33 9 11
Crook 25 15 31 13 16
Fremont 31 16 30 10 13
Goshen 28 16 28 11 17
Hot Springs 22 13 29 15 21
Johnson 23 17 29 14 18
Laramie 29 21 30 9 11
Lincoln 29 18 30 11 12
Natrona 30 19 31 9 13
Niobrara 25 13 31 12 19
Park 24 17 30 13 16
Platte 28 14 31 12 17
Sheridan 24 17 30 13 16
Sublette 25 18 33 13 11
Sweetwater 29 20 32 11 9
Teton 20 25 35 12 8
Uinta 32 19 32 10 7
Washakie 27 14 30 13 17
Weston 23 17 31 13 16
Note: Some county percentages may not total to 100 percent due to rounding.
3-6

3.0 SETTING
During the 1990s, the population of Wyoming’s 24 to 44 age group declined about 12 percent
while the 45 to 64 group increased by 39 percent (Foulke et al., 2000). This increasing proportion of
older residents is likely due to three factors: the aging of the large baby boom generation as seen across
the U.S., the in-migration of retirees seeking Wyoming’s low cost of living, and the out-migration of
young people looking for employment opportunities.
3.2.3 Employment and Labor Force Participation
Population, labor force, employment, unemployment, and average wages are summarized in
Table 3-5. This information is for 2004, the most recent data. The state’s unemployment rate was 3.9
percent. The average wage was $31,210. In 1970, it was estimated that 11.7 percent of the population
was below the poverty level; in 2000, 11.4 percent of the population was below the poverty level.
The labor force participation rate is the percentage of residents in a given region over the age of
16 who are employed or actively seeking work. In 2000, the labor participation rate for Wyoming was 70
percent (Equality State Almanac, 2006).
As of 2000, there were over 328,000 full-time or part-time jobs in Wyoming. From about 1970 to
2000, statewide employment grew at an average rate of 2.5 percent annually. The Energy Bust is
reflected in a drop in employment during the early 1980s.
The proportion of Wyoming employment by economic sector compared to the nation provides
insight into which sectors are most important to the regional economic base and which economic sectors
lag behind national averages. The government sector makes up 20 percent of the employment in
Wyoming compared to 14 percent nationally. The federal government controls a large portion of the land
in the state as discussed in Section 3.1.1. State government, F.E. Warren Air Force Base, the University
of Wyoming, and local government further contribute to large employment needs in the government
sector (Equality State Almanac, 2006).
Mining in Wyoming accounts for about 9 percent of all jobs compared to 0.5 percent nationally.
The mining industry is a significant employer in all river basins with the exception of the Snake/Salt
River Basin (Equality State Almanac, 2006).
Production agriculture also plays a larger role in Wyoming than in the nation as a whole,
contributing about 4.6 percent of statewide employment compared to 3.2 percent nationally. However,
Wyoming’s manufacturing sector is smaller than the national average, accounting for only about 4
percent of total state employment compared to 12 percent nationally (Equality State Almanac, 2006).
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3.0 SETTING
Table 3-5 2004 Population Characteristics
County Population Labor Force Employment Unemployment
Unemployment
Rate
Average
Annual
Wages
Albany 31,473 20,298 19,661 637 3.1 $26,224
Big Horn 11,416 5,480 5,225 255 4.7 $28,756
Campbell 36,721 22,455 21,755 700 3.1 $40,857
Carbon 15,271 7,818 7,462 356 4.6 $27,106
Converse 12,515 6,680 6,412 268 4.0 $31,188
Crook 6,006 3,303 3,177 126 3.8 $26,596
Fremont 36,310 18,204 17,263 941 5.2 $26,454
Goshen 12,286 6,005 5,745 260 4.3 $23,017
Hot Springs 4,598 2,416 2,322 94 3.9 $22,368
Johnson 7,657 3,798 3,669 129 3.4 $24,054
Laramie 85,296 42,699 40,764 1,935 4.5 $31,007
Lincoln 15,626 8,213 7,893 320 3.9 $31,099
Natrona 69,010 39,872 38,387 1,485 3.7 $32,284
Niobrara 2,272 1,164 1,120 44 3.8 $21,749
Park 26,516 14,897 14,290 607 4.1 $26,124
Platte 8,666 4,207 3,993 214 5.1 $28,777
Sheridan 27,163 15,441 14,844 597 3.9 $28,087
Sublette 6,654 4,603 4,499 104 2.3 $31,891
Sweetwater 37,758 21,846 21,087 759 3.5 $38,922
Teton 18,964 13,972 13,516 456 3.3 $31,431
Unita 19,772 10,906 10,464 442 4.1 $29,174
Washakie 7,939 4,346 4,166 180 4.1 $28,301
Weston 6,640 3,227 3,098 129 4.0 $25,446
WYOMING 506,529 281,850 270,812 11,038 3.9 $31,210
Source: Equality State Almanac 2006 State of Wyoming
3.2.4 Key Economic and Water Use Sectors
Agriculture’s impact on the state’s land and water use is significant. Approximately 14 percent of
the total employment in Wyoming is farm and farm-related employment. Table 3-6 shows the farm and
farm-related employment. The energy and mineral sectors have historically added volatility to the
economy, but they have also provided high-paying jobs and often require a large amount of water. While
municipal water consumption is a small percentage of overall water used in the state, cities and towns
have unique requirements that demand reliability. Travel, tourism, and recreation contribute to
Wyoming’s economy, and water plays an important, but somewhat different, role in this sector.
Environmental water use is notable and indirectly affects the economy. Finally, there is an ongoing effort
to attract new business and manufacturing interests to the state, which in the long run may increase the
economic base and create new demand for water supplies. The future of each of the water demand
sectors is integral to economic, demographic, and water demand projections for Wyoming.
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3.0 SETTING
Table 3-6 Farm and Farm-Related Employment, 2002
Farm
Total 1 Metro Nonmetro
industries Employment % of total Employment % of total Employment % of total
Farming:
Farm
production 12,397 3.66 1,381 1.35 11,016 4.64
Farm
proprietors 8,870 2.62 870 0.85 8,000 3.37
Farm Wage &
Salary Workers 3,527 1.04 511 0.50 3,016 1.27
Closely related:
Agricultural
services 1,611 0.48 348 0.34 1,263 0.53
Agricultural
inputs
industries 763 0.22 88 0.09 675 0.28
Agricultural
processing and
marketing 1,191 0.35 49 0.05 1,142 0.48
Peripherally related:
Agricultural
wholesale &
retail trade 31,807 9.38 9,372 9.19 22,435 9.46
Indirect
agribusiness 506 0.15 3 0.00 503 0.21
Total farm &
farm-related
employment 48,275 14.24 11,241 11.03 37,034 15.61
All other
employment 290,846 85.76 90,705 88.97 200,141 84.39
Total
employment 339,121 100.00 101,946 100.00 237,175 100.00
1 Metro and nonmetro detail may not add to total because of some employment not classified by location.
Metro and nonmetro estimates are based on the June 2003 metropolitan area definitions.
Data are based on the 1997 North American Industry Classification System (NAICS).
Source: Most industry estimates were developed from an enhanced file of the County Business Patterns, U.S. Bureau of the Census. Farm
proprietors and farm wage and salary workers are from the Bureau of Economic Analysis, U.S. Department of Commerce.
Agriculture
Wyoming’s agriculture is dominated by livestock production: $798,800,000 in cash receipts came
from livestock and related products in 2000 compared to cash receipts from crops of $160,600,000
(Equality State Almanac, 2006). Much of agriculture’s water use is tied to production of forage and feed
base for the livestock industry. Agriculture consumptively uses more water than any other economic
sector. The river basin studies show total irrigated lands of about 2,070,406 acres while the 2002 Census
of Agriculture, Farm and Ranch Irrigation Survey shows 1,541,688 acres. The 1997 Census of
Agriculture reported 1,749,908 acres irrigated. The difference in census data may be due to the drought
conditions, categories reported, non-responders, and idle lands not being reported.
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3.0 SETTING
Livestock
As of 2004, there were about 1,400,000 cattle and calves on Wyoming ranches. This is a decline
from 2000 when there were about 1,580,000 head. This decline is primarily due to the severe drought
that the state has been experiencing since 2000. Sheep numbers have been impacted similarly. Breeding
sheep numbers declined from about 460,000 head in 2000 to about 340,000 head in 2004.
Ranchers in Wyoming depend on forage to supplement the hay they feed their animals.
Therefore, during drought, they cannot afford to raise as many cattle and sheep. Although hay and alfalfa
are grown across the state, many areas of the state are net importers of hay. Much of this hay comes from
the more intensely farmed areas of the state.
Most of the grazing land in the eastern portion of the state is privately held minimizing reliance
on public land for grazing. However, in the western portion of the state, public grazing land is very
important. Therefore, federal grazing policy can significantly impact the livestock industry and the
agriculture sector.
Crops
Cropping patterns and livestock production are closely related. Alfalfa and other hay account for
over 75 percent of harvested cropland in Wyoming, and much of this hay is used to feed livestock. Other
irrigated crops include corn, dry beans, sugar beets, barley, winter wheat, oats, and spring wheat. Most
irrigation is by flood, but use of center pivot sprinklers is increasing in some areas. Surface water is the
most common irrigation water source, though groundwater is increasingly prevalent.
Industrial
The chart below shows the employment and annual payroll in the industrial sector and related
sectors in Wyoming. These sectors account for 28 percent of the total employment in the state but
account for 41 percent of the payroll making industry a very important economic sector.
Industry can be broken out into mining, utilities, construction, manufacturing, and transportation
and warehousing. Crude oil and natural gas are produced in most counties throughout Wyoming;
however, the production and employment vary. The top oil-producing county is Campbell followed by
Park. The top natural gas- producing county is Sublette followed by Campbell.
Coal mining is concentrated in five counties: Campbell, Carbon, Converse, Lincoln, and
Sweetwater; in 2004, total coal production was 395,726,000 tons (Equality State Almanac, 2006). Other
minerals produced in Wyoming include trona, bentonite, uranium, sand and gravel, stone, and other
miscellaneous minerals.
Wyoming has numerous electrical generating facilities that make up the utilities subsector.
Water-using electrical generating facilities can be broken out into two groups, hydropower facilities and
coal-fired plants. Table 3-7 provides the number of electric power generating facilities by river basin for
Wyoming.
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3.0 SETTING
2003 Industrial Employment and Annual Payroll
Transportation and
Warehousing
6,835 employees
earning
$230,877,000
Mining
16,824 employees
earning
$917,049,000
Manufacturing
10,368 employees
earning
$416,483,000
Construction
14,445 employees
earning
$502,115,000
Notes: Mining includes oil and gas.
The data was sorted by number of employees per sector.
Source: Equality State Almanac, 2006
Utililties
2,313 employees
earning
$142,785,000
Table 3-7 Electric Power Generating Facilities
River Basin Hydropower Coal-fired Subtotal
Green 1 2 3
Northeast Wyoming 4 4
Platte 6 2 8
Snake/Salt 1 1
Wind/Bighorn 6 6
TOTAL 14 8 22
Municipal and Domestic
Municipal and domestic water use is a relatively small but important part of overall water use.
Wyoming has 99 incorporated municipalities of which 19 are “first class cities.” A first class city is
defined by Wyoming State Statute 15-3-101 as a city that has a population of at least 4,000 and has made
a public proclamation. According to the 1973 Wyoming Framework Water Plan, Wyoming’s population
in 1970 was 332,416, with about 60.5 percent (approximately 201,111) of the population living in cities
and towns and the remaining 39.5 percent (approximately 131,305) living on ranches, on farms, and in
nonfarm areas outside urban area boundaries. Between 1970 and 2000, the population increased by 49
percent (approximately 162,884 people) to 493,782. Census data for 2000 indicate that nearly 35 percent
of the population resides in rural areas and the remaining 65 percent resides in urban areas (Equality State
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3.0 SETTING
Almanac, 2006). This indicates that the urbanization trend noted in the 1973 Wyoming Framework
Water Plan is continuing.
The vast increase in population means increased water needs and use in both rural and urban
sectors. Jacobs and Brosz (2000) report that 80-85 percent of water consumption is for irrigated
agriculture, yet there is an increasing water demand for municipal and industrial uses.
Recreation, Travel, and Tourism
Wyoming’s Northwest area, Wind/Bighorn River Basin, and Snake/Salt River Basin are
nationally known recreation areas. The Wyoming State Parks and Recreation Areas are regionally
significant recreation destinations. Water is rarely consumed in recreational use, the maintenance of golf
courses being one exception. Water is an important aspect in recreation and tourism. Wyoming provides
opportunities for boating, fishing, hunting, camping, golfing, and skiing. Much of this activity takes place
on or near the rivers, streams, lakes, and reservoirs of Wyoming.
Each river basin has major reservoirs that were constructed for flood control, irrigation, power
generation, and/or municipal water supply and do not have recreation reserve pools. As a result,
recreational use at the reservoirs peaks in July and then declines as water levels are drawn down to satisfy
their permitted uses.
Golfing is a growing portion of the recreation sector: e.g., the Platte River Basin has 19 golf
courses, and the Snake/Salt River Basin has 5 golf courses. As population increases, demand for more
courses will follow.
Environmental
For the purposes of water demand forecasting, environmental water use includes only water used
in efforts to enhance environmental conditions, such as improving or maintaining fish and wildlife
habitats. Much of the environmentally beneficial water use within the state is a by-product of other uses,
such as reservoirs, and not from water rights specifically directed at environmental protection.
Wyoming’s instream flow law is one exception and is designed to protect and enhance fisheries.
Enhancement or creation of wetlands is an environmental use that may see more development in
the future. State and federal funding sources exist to assist landowners in developing or enhancing
wetlands.
3.3 LEGAL AND INSTITUTIONAL SETTING
The constraints or bounds that water users must operate within are defined by a mixture of state
law, federal law, interstate agreements, and court decrees. Figure 3-7 depicts Wyoming river basin
compacts and decrees.
3.3.1 Wyoming Water Rights
The Wyoming Water Development Commission (WWDC) has
stated that Wyoming water law shall be respected in all aspects of the
water planning process. Wyoming water law is the foundation upon
which all water use, development, and protection are based. The water
rights system in Wyoming is administered by the State Engineer's
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3.0 SETTING
Office and State Board of Control, both constitutionally based administrative and quasi-judicial entities of
state government.
Wyoming's water laws have evolved from the early establishment of legal principles that were
later embodied in the state's constitution and a series of statutory laws written and adopted early in
Wyoming's history that have stood the test of time. One early water dispute that involved two territorial
pioneers, William McCrea and Charles Moyer, is instructive regarding the history of water law in
Wyoming. Moyer, whose name is associated with a now-famous spring in the coal-mining region north
of Gillette, developed that spring for irrigation in 1890. Previously, McCrea developed an irrigation
project along the Little Powder River downstream of, and partially supplied by, Moyer's spring. With
Moyer's development, McCrea's ditch was short of water, and the resulting argument eventually reached
the Wyoming Supreme Court. In one of its first rulings on water matters, the Court affirmed the "first in
time, first in right" doctrine by siding with McCrea. Through this 1896 ruling, the Court recognized the
concepts of the prior appropriation doctrine that Territorial Engineer Elwood Mead had been advocating
in the days leading to statehood and the constitutional conventions.
Mead, who became the first State Engineer, understood that water in an arid region must be
administered in a predictable and equitable fashion, and the methods he fostered were to allow the earlier
developer of water to establish the senior right for its continued use. The Wyoming State Constitution
adopted this priority system of appropriation and established the position of State Engineer. Through the
efforts of Mead, the Constitution also embodied the basis of appropriating water on the concept of
"beneficial use" to avoid the potential for exaggerated amounts of water being tied up by early settlers and
developers of water diversion systems. Mead was also at the forefront of affirming a strong, active,
independent state role in all aspects of appropriating and administrating the waters of the state. He also
developed the process for resolving water disputes. Rather than use a water court system as in the
neighboring state of Colorado, Wyoming established the State Board of Control within its Constitution.
In addition to its independent authority to review matters initially decided by the State Engineer, the
Board of Control is the adjudicator of all water rights and the decision-maker of all requests for changes
to water rights. The Constitution declares all water in the state to be the property of the State, subject to
appropriation for beneficial use through the administrative permitting of water rights. Water rights are
considered property rights that attach to the land or place of use. However, the law provides that the
owner of these rights may change the location of use, or the type of use, by seeking approval from the
Board of Control. The final decisions of the Board of Control are subject to judicial review. The Board
of Control is made up of the State Engineer and the four Water Division Superintendents.
Within this constitutional framework, the detailed statutory authority, procedures, and
administration were further defined by legislation and periodic Court decisions. The State Engineer's role
is defined in Title 9, Chapter 1, Article 9, along with the general authority to establish fees for certain
services and some other minor activities of the agency.
The majority of Wyoming's water laws are now codified primarily in Title 41 of Wyoming
Statutes, entitled "Water." Under this title, there are 14 chapters that include the authority and activities
of the Water Development Commission and the laws associated with irrigation, drainage, watershed
improvement, water and sewer districts, interstate compacts, and the use of watercraft. Chapters 3 and 4
contain the important laws relating to the appropriation, administration, and adjudication of water rights
in Wyoming. These statutes relate to all waters of the state, whether they are from surface streams,
springs, natural lakes, or underground waters.
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3.0 SETTING
The key elements of Wyoming's water laws were established in the Constitution and the early
statutory laws before and near the turn of the century. From time to time, the legislature has modified the
laws to address emerging new issues of the water users in the state. The laws addressing reservoirs were
passed in the early 1900s; laws specific to groundwater sources were introduced in the 1940s and 1950s,
with the last significant change adopted in 1969. Laws addressing instream flow water rights were
codified in 1986. The basic framework of water right permitting actions and administration has remained
the same, all the while allowing for flexibility in answering the needs of water users.
This set of laws is a part of the principles upon which the Framework Water Plan is based.
3.3.2 Interstate Compacts, International Treaty, Court Decrees, and Contracts and
Agreements
NOTE: Additional information on water rights, compacts, court decrees, international treaty, and
interstate agreements is available online at http://seo.state.wy.us.
Amended Bear River Compact (1978)
This compact provides that in the administration of the Bear River among the States of Idaho,
Utah, and Wyoming, the river shall be divided into three divisions. When a water emergency exists, water
administration is handled as discussed below.
Upper Division
This division is the portion of the Bear River from its source in the Uinta Mountains to and
including Pixley Dam. A water emergency shall be deemed to exist when the total divertible flow is less
than 1,250 cubic feet per second (cfs). Divertible flow is allocated for diversion as follows:
Upper Utah Section Diversions . . . . . . . . . . . . . . . . . . . . . . 0.6%
Upper Wyoming Section Diversions . . . . . . . . . . . . . . . . . 49.3%
Lower Utah Section Diversions . . . . . . . . . . . . . . . . . . . . . 40.5%
Lower Wyoming Section Diversions . . . . . . . . . . . . . . . . . . 9.6%
Central Division
This division is the portion of the Bear River from Pixley Dam to and including Stewart Dam. A
water emergency shall be deemed to exist when the total divertible flow is less than 870 cfs or the flow of
Bear River at Border gaging station is less than 350 cfs, whichever occurs first. When such a condition
exists, all divertible flow in this division shall be allocated such that the portion of the river between
Pixley Dam and the point where the river crosses the Wyoming-Idaho line near Border shall be limited
for the benefit of the State of Idaho, 43 percent of the divertible flow. The remaining 57 percent of the
divertible flow shall be available for use in Idaho in the Central Division, but if any portion of such
allocation is not used therein, it shall be available for use in Idaho in the Lower Division.
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3.0 SETTING
Lower Division
This division is the portion of the Bear River between Stewart Dam and the Great Salt Lake,
including Bear Lake and its tributary drainage. The original compact grants to Wyoming and Utah the
right for each to store, above Stewart Dam, an additional 17,750 acre-feet of Bear River water in any
water year and to Idaho the right to store 1,000 acre-feet of water in Idaho or Wyoming on Thomas Fork
for use in Idaho. In addition, the Amended Compact (1978) allocates further storage entitlements to Utah
and Wyoming for 70,000 acre-feet of Bear River water, in any water year, above Stewart Dam to be
divided equally and to Idaho an additional 4,500 acre-feet of Bear River water in any water year to be
stored in Idaho or Wyoming for use in Idaho. Water rights granted on water appropriated under this last
entitlement, including groundwater tributary to the Bear River, which is applied to beneficial use on or
after January 1, 1976, shall not result in an annual increase in depletion of the flow of the Bear River and
its tributaries above Stewart Dam of more than 28,000 acre-feet in excess of the depletion as of January 1,
1976. Thirteen thousand acre-feet of the additional depletion above Stewart Dam are allocated to each of
Utah and Wyoming, and 2,000 acre-feet are allocated to Idaho. Idaho, Utah, and Wyoming are also
granted the right to store and use water above Stewart Dam that otherwise would be bypassed or released
from Bear Lake at times when all other direct flow and storage rights are satisfied. Water availability and
depletions are calculated and administered by procedures approved by the Bear River Commission.
Belle Fourche River Compact (1943)
The compact for the division of the waters of the Belle Fourche River between Wyoming and
South Dakota was negotiated and ratified by the two states and the federal government in 1943. This
compact recognizes all existing rights in Wyoming, as of the date of the compact, and permits the
construction of stock water reservoirs not exceeding 20 acre-feet in capacity. As of the date of the
compact, the unappropriated waters of the Belle Fourche River are allocated as follows: 10% to Wyoming
and 90% to South Dakota. Another provision states that, as of the date of the compact, no reservoir built
exclusively to use the water allocated to Wyoming can exceed a capacity of 1,000 acre-feet.
Colorado River Compacts (1922 and 1948).
A compact between the Upper Colorado River Basin states (Wyoming, Colorado, New Mexico,
and Utah) and the Lower Colorado River Basin states (Arizona, Nevada, and California) was negotiated
in 1922. This compact allocated 7,500,000 acre-feet of consumptive use annually to the Upper Basin. It
also provided that a minimum flow of 75,000,000 acre-feet in any consecutive 10-year period should be
maintained at Lee Ferry, which is the point on the river dividing the Upper Basin from the Lower Basin.
In addition, provision was made for future treaties with Mexico. As a result of this clause, the 1944
Colorado, Tijuana, and Rio Grande Treaty indirectly influences the regulation of the Colorado River. In
1948, a compact among the Upper Basin states was negotiated. It was ratified by all the states and the
federal government in 1949. Arizona has a small area in the Upper Basin and therefore was included in
the Upper Basin negotiations. This Upper Colorado River Basin Compact apportions the use allocated to
the Upper Basin by the 1922 compact as follows: 50,000 acre-feet per annum to Arizona and of the
remaining quantity 51.75 percent to Colorado, 11.25 percent to New Mexico, 23 percent to Utah, and 14
percent to Wyoming. The 1948 compact divided the waters of Henry's Fork between Wyoming and Utah
on a straight priority basis for existing development. Waters of the Little Snake River used under rights
existing prior to this compact and diverted below the river’s confluence with Savery Creek are
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3.0 SETTING
administered on a straight priority basis (irrespective of the state line). Water uses developed after the
Compact’s signing are administered to equally share the available water supply.
Upper Niobrara River Compact (1962)
The compact dividing the waters of the Niobrara River between the States of Nebraska and
Wyoming was negotiated by the two states in 1962 and approved by Congress in 1969. Stock water
reservoirs in Wyoming not exceeding 20 acre-feet in capacity are not restricted except by Wyoming law,
and no restrictions were placed on diversion or storage of water in Wyoming. The exception to this
occurs on the main stem east of Range 62 West and on Van Tassel Creek south of Section 27, Township
32 North, Range 60 West. In this area, direct diversions are regulated on an interstate priority basis with
lands in Nebraska west of Range 55 West. Storage reservoirs with priority dates prior to August 1, 1957,
may store water only during the period of October 1 to June 1, unless water is available after meeting
direct flow appropriations in Wyoming and Nebraska west of Range 55 West. Storage reservoirs with
priority dates after August 1, 1957, may store a maximum of 500 acre-feet in any water year from
October 1 to May 1, unless water is available after meeting direct flow appropriations in Wyoming and
Nebraska west of Range 55 West. Groundwater development was recognized to be a significant factor,
and the compact provides for investigation of this resource and possible apportionment at a later date.
Snake River Compact (1949)
The compact dividing the waters of the Snake River and Salt River between the states of Idaho
and Wyoming was negotiated by the two states in 1949 and ratified by them and the federal government
in 1950. The compact recognizes, without restrictions, all existing rights in Wyoming as of the date of the
compact. It permits Wyoming unlimited use for domestic and stock uses provided that stock water
reservoirs shall not exceed 20 acre-feet in capacity. It permits Wyoming to divert (or store) for new
developments, for supplemental or original supply, 4 percent of the Wyoming-Idaho state line flow of the
Snake River.
Yellowstone River Compact (1950)
The Yellowstone River Compact dividing the waters of the tributaries (Clarks Fork, Big Horn,
Tongue, and Powder) of the Yellowstone among the states of Wyoming, Montana, and North Dakota was
negotiated in 1950 and ratified by the three states and the federal government in 1951. Existing rights as
of January 1, 1950, maintain their status in accordance with the laws governing the acquisition and use of
water under the doctrine of prior appropriation. In addition, existing and future domestic and stock water
uses including stock water reservoirs up to a capacity of 20 acre-feet are exempted from provisions of the
Compact. The unappropriated or unused total divertible flow of each tributary, after needs for
supplemental supply for existing rights are met, is allocated to Wyoming and Montana as follows:
Clarks Fork of the Yellowstone River:
Wyoming . . . . . . . . . . . . . . 60%
Montana . . . . . . . . . . . . . . . 40%
Big Horn River (exclusive of Little Big Horn River):
Wyoming . . . . . . . . . . . . . . 80%
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3.0 SETTING
Montana . . . . . . . . . . . . . . . 20%
Tongue River:
Wyoming . . . . . . . . . . . . . . 40%
Montana . . . . . . . . . . . . . . . 60%
Powder River (including the Little Powder River):
Wyoming . . . . . . . . . . . . . . 42%
Montana . . . . . . . . . . . . . . . 58%
International Treaty
The Mexican Water Treaty between the United States and Mexico dated 1944 dividing the waters
of the Colorado River, which flows from the United States into Mexico, also affects Wyoming. This
treaty guaranteed to Mexico the delivery of 1,500,000 acre-feet of water per annum. Under the terms of
the 1922 Colorado River Compact, the burden of supplying this water to Mexico during periods of short
water supplies is equally borne by the Upper Basin, of which Wyoming is a part, and the Lower Basin.
The Colorado River Basin Project Act (PL 90-537, Sec. 202) provides that the satisfaction of the
requirements of the Mexican Water Treaty from the Colorado River constitutes a national obligation
which shall be met by any augmentation project developed under the provisions of the Act.
Court Decrees
North Platte River
During the mid-1930s, the state of Nebraska filed an action against the States of Colorado and
Wyoming in the Supreme Court of the United States over the flows of the North Platte River. In 1945, the
Court handed down a decree equitably apportioning the waters of the North Platte among the states. The
decree included the following provisions:
(a) Exclusive of the Kendrick Project and Seminoe Reservoir, the State of Wyoming is enjoined
from diverting water from the North Platte River above Guernsey Reservoir and from the North Platte
River and its tributaries above Pathfinder Dam for the irrigation of more than a total 168,000 acres of land
during irrigation season.
(b) Exclusive of the Kendrick Project and Seminoe Reservoir, the State of Wyoming is enjoined
from storing more than 18,000 acre-feet of water from the North Platte River and its tributaries above
Pathfinder Reservoir for irrigation purposes during any one year.
(c) The storage rights of Pathfinder, Guernsey, Seminoe, and Alcova Reservoirs are junior to
1,165 cfs for the irrigation of land in Western Nebraska, and the State of Wyoming is enjoined from
storing or permitting the storage of water in these reservoirs other than in accordance with the rule of
priority.
(d) The natural flow of the North Platte River in the section of the river between the Whalen
Diversion Dam, downstream of the Tri-State Dam, or approximately the Wyoming-Nebraska state line,
between May 1 and September 30 of each year is apportioned 25 percent to Wyoming and 75 percent to
Nebraska.
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3.0 SETTING
It also limits Colorado to the irrigation of 135,000 acres; the storage of 17,000-acre-feet of water
in any one year; and the diversion of an average 6,000 acre-feet out of the North Platte River Basin
annually.
By stipulation agreed upon by the three States and approved by the Supreme Court of the United
States, the decree was amended in 1953 as follows:
Colorado was permitted to increase its irrigated acreage to 145,000 acres, and the States of
Wyoming and Nebraska were permitted to store 40,000 acre-feet during any water year in Glendo
Reservoir, with such storage, including holdover, never to exceed 100,000 acre-feet. The 40,000 acre-feet
of storage during the year is divided 25,000 acre-feet to Nebraska and 15,000 acre-feet to Wyoming.
Nebraska filed a lawsuit in the Supreme Court of the United States on October 6, 1986, alleging
that Wyoming had violated certain aspects of the 1945 Decree. The U.S. Supreme Court approved the
Final Settlement Stipulation and entered the Modified Decree on November 13, 2001. The Final
Settlement Stipulation and the Modified Decree include the following provisions:
(a) For the North Platte River and its tributaries, including water from hydrologically connected
groundwater wells, upstream of Pathfinder Dam and between Pathfinder Dam and Guernsey Reservoir,
Wyoming is enjoined from consuming more than the largest amount of water consumed for irrigation
from such sources in any 10 consecutive year periods between 1952 and 1999, inclusive. Pursuant to the
methodology approved by the parties, the largest amount of water during the 10-year period noted above
is 1,280,000 acre-feet upstream of Pathfinder and 890,000 acre-feet between Pathfinder and Guernsey.
(b) Exclusive of the Kendrick Project, for the North Platte River and its tributaries upstream of
Guernsey Reservoir including water from hydrologically connected groundwater wells, Wyoming is
enjoined from intentionally irrigating more than a total of 226,000 acres of land during any one irrigation
season. Ten years following the settlement date, this provision will be replaced with two injunctions: one
intentionally irrigated limitation for the area above Pathfinder and one for the area between Guernsey and
Pathfinder. The total of the two shall not exceed 226,000 acres.
(c) Exclusive of Wheatland Irrigation District, for the Laramie River and its tributaries including
hydrologically connected groundwater wells downstream of Wheatland Irrigation District’s Tunnel No. 2,
Wyoming is enjoined from intentionally irrigating more than a total of 39,000 acres of land during any
one irrigation season.
(d) In accordance with an April 20, 1993 U.S. Supreme Court opinion, Inland Lakes has the
priority of December 6, 1904, and the United States has the right to accrue up to 46,000 acre-feet of water
during the nonirrigation season months of October, November, and April for storage in the four Inland
Lakes located in Nebraska.
(e) As in the 1945 Decree, natural flow of the North Platte River in the section of the river
between Whalen Diversion Dam and Tri-State Dam, between May 1 and September 30 of each year, is
apportioned 25 percent to Wyoming and 75 percent to Nebraska.
(f) Within the area bounded by Whalen Diversion Dam on the west, 300 feet south of the Fort
Laramie Canal on the south, one mile north of the Interstate Canal on the north, and the Wyoming-
Nebraska state line on the east, diversions between May 1 and September 30 for irrigation purposes from
groundwater wells with water right priorities after October 8, 1945, shall be replaced, or the pumping
shall be regulated to prevent such diversions.
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(g) Within the area bounded by Whalen Diversion Dam on the west, the Fort Laramie Canal on
the south, the Interstate Canal on the north, and the Wyoming-Nebraska state line on the east, surface
water diversions for irrigation purposes from the tributaries to the North Platte River shall be
administered and accounted as diversions of natural flow in accordance with the equitable apportionment
of natural flow, 25 percent to Wyoming and 75 percent to Nebraska in the section of the river between
Guernsey and Tri-State Dam. For the depletions that occur when natural flow is insufficient to meet the
demands of both Wyoming and Nebraska irrigators who divert from the North Platte River at or above
Tri-State Dam, Wyoming must replace the depletion amount, or those irrigation rights not in priority to
divert shall be regulated to prevent such diversions.
(h) By stipulation of all three States and the United States in September 1997, Wyoming shall
install measuring devices at no fewer than eight of the largest irrigation reservoirs storing water from the
North Platte River and its tributaries upstream of Pathfinder Reservoir, to accurately measure the annually
accrued irrigation storage in each reservoir. The storage limitation injunction from the 1945 Decree is
unchanged in the 2001 Modified Decree: Wyoming is enjoined from storing or permitting the storage of
more than 18,000 acre-feet of water for irrigation purposes upstream of Pathfinder Reservoir exclusive of
Seminoe Reservoir during any one year.
(i) By stipulation of Nebraska, Wyoming, and the United States in December 1998, referred to as
the 1998 Allocation Stipulation, the parties jointly agreed to a method of allocating storage water during
periods of shortage. The U.S. Bureau of Reclamation (USBR) shall follow procedures and guidelines
when allocating storage water from Pathfinder and Guernsey Reservoirs and the Inland Lakes. During the
first week in February, March, and April, the USBR shall advise the other parties when the current year is
likely to be an “allocation year” if storage and forecasted water supplies are less than the approximate
irrigation demand for the year of 1,100,000 acre-feet. With respect to water rights administration
upstream of Pathfinder Reservoir before May 1, if the USBR advises that the current year is a likely
allocation year, the Reclamation shall be deemed to have placed a priority call for Pathfinder Reservoir,
excluding the Pathfinder Modification Project. With respect to water rights administration along the
mainstem of the North Platte River and the tributaries between Pathfinder Dam and Guernsey Reservoir
before May 1, if the USBR advises that the current year is a likely allocation year, then the USBR shall be
deemed to have placed a priority call for Inland Lakes (April only), Guernsey Reservoir, and Glendo
Reservoir storage rights. In both situations described above, the Wyoming State Engineer shall determine
whether the calls are valid and warrant regulation upstream of the calling right. Any resulting
administration will cease as of May 1, the first day of the irrigation season. Between May 1 and
September 30 during an allocation year, Wyoming will limit the cumulative diversions for irrigation
purposes from the mainstem of the North Platte River between Pathfinder Dam and Guernsey Reservoir
to 6,600 acre-feet per two-week period.
(j) By an amended stipulation of all three States and the United States in March 2001, the
Pathfinder Modification Stipulation includes the following provisions:
(i) The capacity of Pathfinder Reservoir may be increased by approximately 54,000 acre-feet to
recapture original storage space lost to sediment.
(ii) The recaptured space would store water under the existing 1904 storage right for Pathfinder
Reservoir except that it could not place regulatory calls on existing upstream water rights other than the
rights pertaining to Seminoe Reservoir.
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(iii) Approximately 34,000 acre-feet of the 54,000 acre-feet of recaptured space would be
accounted for in an environmental account and operated for the benefit of endangered species and their
habitat in central Nebraska.
(iv) Wyoming has the exclusive right to contract with the USBR for the use of the remaining
20,000 acre-feet of the recaptured capacity. The primary use of the 9,600 acre-feet of annual estimated
firm yield from this “Wyoming Account” is to supplement Wyoming municipalities’ water right needs.
The account’s other uses in prioritized order are: to serve as Wyoming’s source of replacement water
required by the Modified Decree, to replace Wyoming’s excess depletions from existing water-related
activities under the Platte River Recovery Implementation Program (PRRIP), or to be leased to a program
for endangered species recovery.
(k) The North Platte Decree Committee (NPDC) was created to assist in monitoring,
administering, and implementing the Modified Decree and the Final Settlement Stipulation. The NPDC
shall act in accordance with the NPDC Charter and may modify by unanimous agreement the
administrative procedures attached as Exhibits 3 through 12 to the Charter.
(l) The river carriage and reservoir loss calculations established in the 1945 Decree have been
replaced with the procedures defined in Exhibit 9 to the NPDC Charter.
(m) Upon occurrence of ‘negative natural flow at Orin’, as defined in Exhibit 7 of the NPDC
Charter, the Wyoming State Engineer will administer water rights or take other action as necessary to
eliminate the negative natural flow at Orin.
(n) Within five years of the Court-approved settlement date, pursuant to Wyoming law, Wyoming
will adjudicate the following:
(i) All unadjudicated groundwater permits for irrigation wells hydrologically connected to the
North Platte River or its tributaries above Guernsey Reservoir and wells hydrologically connected to the
Laramie River or its tributaries downstream of Wheatland Tunnel #2, exclusive of the Wheatland
Irrigation District.
(ii) All existing unadjudicated groundwater permits for irrigation wells within the area bounded
by Whalen Diversion Dam on the west, 300 feet south of the Ft. Laramie Canal on the south, one mile
north of the Interstate Canal on the north, and the Wyoming-Nebraska state line on the east.
(iii) All unadjudicated surface water permits for irrigation purposes that divert from tributaries
and drains that lie within the area bounded by Whalen Diversion Dam on the west, the Fort Laramie
Canal on the south, the Interstate Canal on the north, and the Wyoming-Nebraska state line on the east.
Laramie River
In 1911, Wyoming started proceedings in the Supreme Court of the United States against
Colorado to limit Colorado diversions from the Laramie River. In 1922, the Supreme Court handed down
its decree, which allowed Colorado to annually divert 4,250 acre-feet for the meadow lands and 33,500
acre-feet by transmountain diversion plus "the relatively small amount of water appropriated..." from the
headwaters of Deadman Creek, through the Wilson Supply Ditch. In 1936, the Supreme Court stated that
the record showed that the "relatively small amount of water" referred to actually amounted to 2,000 acrefeet
of water per year. Therefore, the total annual diversion allowed Colorado was 39,750 acre-feet. In
1939, Wyoming secured an order from the Supreme Court restraining Colorado from diverting more than
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the 39,750 acre-feet annually that the State had been allotted. The Supreme Court stated that this amount
should be administered according to Colorado laws. By stipulation between Colorado and Wyoming in
1957, the Supreme Court vacated all former decrees and decreed that only 19,875 acre-feet of water per
year could be diverted from the Laramie River Basin and that 29,500 acre-feet per year could be diverted
by the meadow land users for the irrigation of certain lands described by map in the decree.
Teton and South Leigh Creeks
Conflict between the water users on Teton and South Leigh Creeks in Wyoming and Idaho was
settled by a decree of the United States District Court entered February 4, 1941, known as the “Roxana
Decree”. This decree contains a stipulation that the Wyoming users may make unlimited diversions from
Teton Creek and its tributaries until the flow diminishes to 170 cfs. After that, the Wyoming water users
are limited to a diversion of 1 cfs for each 50 acres of land. When the flow further reduces to 90 cfs, the
flow of Teton Creek and its tributaries is divided equally between the Wyoming and Idaho water users.
The Wyoming appropriators are permitted unlimited diversions from South Leigh Creek until the natural
flow of the creek diminishes to a total of 16 cubic feet per second, after which time the Wyoming users
are permitted to divert one-half of the streamflow and the Idaho users are permitted to divert the balance.
Wind/Bighorn River Basin
The two million acre Wind River Indian Reservation, located in
Fremont and Hot Springs Counties, is in the Wind/Bighorn River Basin
(WBHB) watershed. The Wind River and many of its tributaries originate
on or run through the Reservation, making it an important factor in the
WBHB’s water management. In January 1977, the State of Wyoming
enacted Wyoming Statute, 1-37-106 authorizing the State to commence
general stream adjudications. On January 24, 1977, the State filed a
complaint in Washakie County District Court seeking adjudication of the
Bighorn River system and all other sources. In 1979, the Court and the
parties agreed to divide the case into three main phases, Phase I addressing the Indian Reserved Water
rights, Phase II covering all non-Indian federal water rights for the national forests and parks and other
federally owned land, and Phase III covering all state rights evidenced by permits and certificates. During
the adjudication and legal process, many important decisions were issued from the Wyoming Supreme
Court and the United States Supreme Court. At the time of this writing, there exist Big Horn I through
Big Horn VII court decisions. These major decisions cover awards for the Eastern Shoshone and Northern
Arapahoe Tribes and Walton Awards to landowners whose land was derived from allottees lands
ownership along with other significant decisions. There is also a multitude of district court decisions
determining the adjudication of state water rights. Legal proceedings between the State of Wyoming and
the Tribes awarded the right to use nearly 500,000 acre-feet of surface water annually on over 107,000
acres from the Wind River system to the Eastern Shoshone and Northern Arapaho Tribes, although some
tribal members hold water rights individually. The tribal water rights date to July 3, 1868, the date of the
treaty between the United States and the Shoshone Tribe, and are the some of oldest water rights in the
WBHB. Within this award, approximately 209,000 acre-feet for 53,760 acres for irrigation use is
reserved for future agricultural developments on the Reservation. The Tribes sought to use the award as
instream flow for environmental/recreational purposes but failed in court to be granted such changes as
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the award was for use in developing irrigation projects. At the present time, the Tribes have not
beneficially used this water, and downstream users, whose rights are junior to those of the Tribes, are
accustomed to having this water available. Working out a management regime that will satisfy all parties
is a formidable task.
The Reservation includes within its boundaries private lands not owned by the Tribes. The
Reservation operates within a governmental context of tribal, federal, state, and local authority and
activity. Water rights on the Reservation are managed under state law and the Wind River Water Code,
jointly adopted in 1991 by the Tribes (Collins, August, 2000). A Water Resources Control Board is the
Tribes’ “primary enforcement and management agency responsible for controlling water resources on the
Reservation” (Wind River Water Code, 1991). The Big Horn River General Stream Adjudication and the
tribal water rights have a distinct impact on future water planning in the WBHB.
In addition to the tribal rights, under Phase II of the 1979 District Court case, the water rights
were quantified for the United States on national park lands, in forests, and on lands of the Bureau of land
Management and USBR. Several thousand rights were confirmed for use as public water reserves,
instream flow, wells, reservoirs, stock reservoirs and stock driveways, firefighting uses, and discrete
water uses along with other diminimus uses on federal land.
Under Phase III of the case, state water rights adjudication through the District Court has resulted
in reaching final disposition of over 4,000 surface water rights and over 15,000 groundwater rights.
Water rights within the entire Water Division 3 have been affected by a series of court decisions through
the general stream adjudication process, both on and off the reservation. The water rights within the Wind
River Indian Reservation consist of state water rights, tribal water rights, and Walton Awards. Added to
this complexity is the checkerboard ownership pattern resulting in an integrated level of multiple water
rights on the same ditch system which cross-jurisdictional boundaries. Water planning efforts should
always take a comprehensive view of all water rights as they integrate with each other regardless of how
they were derived or awarded by the courts within this complex water system.
3.3.3 Contracts and Agreements
Wyoming has also entered into several agreements that limit or modify water use at specific
locations. A few of the most noteworthy are listed below by river basin.
Green River Basin
Fontenelle Reservoir Contract
Wyoming acquired the right to perpetually market 60,000 acre-feet of Fontenelle Reservoir
storage from the USBR on two separate occasions. A 1958 Act of Congress authorized storage to meet
anticipated future need for municipal and industrial purposes to be included in any reservoir project to be
surveyed, planned, and constructed by the USBR – conditioned upon the willingness of state or local
interests to pay for the cost of providing storage for the anticipated future demands. In 1959, the
Wyoming legislature appropriated the funds and authorized the existing Natural Resource Board to enter
into contract with the USBR for storage in an amount not to exceed 60,000 acre-feet. In 1974, Wyoming
entered into a second agreement with the USBR that authorized Wyoming to market an additional 60,000
acre-feet of Fontenelle Reservoir storage water for municipal and industrial purposes. Therefore,
Wyoming has a right to market 120,000 acre-feet of the 345,397 acre-feet total capacity of Fontenelle
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Reservoir once the proposed sale has been reviewed pursuant to the National Environmental Policy Act
(NEPA) and approved by the WWDC.
Four water sale contracts have been executed, but only one currently calls for the annual release
of Fontenelle water. The three remaining contracts require remittance of a “readiness to serve fee,” which
reserves an amount of water specified in the contract which may be released as requested by the
contractor. If all four contracts called for their associated releases, the amount of water released would
total 46,550 acre-feet. Therefore, depending on water availability, Wyoming has the right to market an
additional 73,450 acre-feet of Fontenelle Reservoir water.
High Savery Reservoir Contract
Construction of the High Savery Reservoir was authorized by the Wyoming legislature to provide
water for recreation, agriculture, municipal and domestic water supplies, environmental enhancement, and
mitigation of the Cheyenne Stage I and Stage II transbasin diversion water supply projects. The
permitted capacity of the reservoir is 22,433 acre-feet. A 5,724 acre-feet minimum pool requirement was
stipulated in the Clean Water Act, Section 404 permit, issued by the U.S. Army Corps of Engineers
(USCOE). The USCOE 404 Permit also mandated maintenance of a 12 cfs nonirrigation season flow in
Savery Creek below the dam. If actual inflows are less than 12 cfs, the flows are required to match the
actual reservoir inflows. Further, the State is to maintain a flow of 10 cfs from July 15 through
September 15 below the dam regardless of reservoir inflows. The State has contracted with the Little
Snake River Conservancy District (District) for the sale of water residing above the elevation of the
minimum pool. The District is responsible for remarketing water pursuant to the beneficial purposes
described by the enabling legislation. The primary purpose of the reservoir, however, is to provide firm,
reliable late-season irrigation water, eight out of 10 years, to lands within the Little Snake River Basin.
Platte River Basin
Cooperative Agreement
In 1997, the States of Colorado, Wyoming, and Nebraska and the U.S. Department of the Interior
(DOI) signed the Cooperative Agreement for Platte River Research and Other Efforts Relating to
Endangered Species Habitat Along the Central Platte River, Nebraska (Agreement). The Agreement
addressed recovery of four species: the whooping crane, piping plover, least tern, and pallid sturgeon.
The final environmental impact statement (EIS) and the biological opinion were distributed in May and
June 2006. The Record of Decision was signed by the DOI Secretary Kempthorne on September 27,
2006.
Platte River Recovery Implementation Program (PRRIP)
The federal/state basinwide PRRIP addresses recovery of the endangered species in the Central
Platte River in Nebraska. The PRRIP agreement was signed by the Governors of Colorado, Nebraska,
and Wyoming and the Secretary of Interior in late 2006. The PRRIP will remain in effect for the first
increment, 13 years, unless terminated earlier by one of the signatory parties. The PRRIP which began on
January 1, 2007 is estimated to cost $317 million, with the federal share being $157 million (2005
dollars). Wyoming’s 2006 legislature approved $6 million in funding for the PRRIP and $8.5 million for
the Pathfinder Modification Project, to recover 54,000 acre-feet of space in Pathfinder Reservoir. The
Pathfinder Modification Project provides a municipal water supply, a water supply to help meet
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obligations of Wyoming under the Modified North Platte Decree, and enhancement of regulatory
certainty under the federal Endangered Species Act (ESA).
In the absence of the PRRIP, each water project or activity in the Platte River Basin having a
federal nexus will be required to address and comply with federal ESA regulations individually, a process
that could be costly and inefficient and would severely impact the states and their water users.
Glendo Reservoir Contract
The total storage capacity of the USBR’s Glendo Reservoir is 428,405 acre-feet, which includes
the flood surcharge pool, a space to accommodate restoring the USBR’s winter releases from Pathfinder
Reservoir, temporary storage of the Inland Lake ownership, the impoundment of water for the purpose of
creating head for production of hydropower and a maximum, not-to-exceed, 100,000 acre-feet
conservation pool. In 1996, the parties to the Nebraska v Wyoming lawsuit agreed to a stipulation that
amended the “1953 Order to Provide for Use of Glendo Storage Water” (1953 Order), which was
incorporated as an exhibit to the “Proposed Joint Settlement” that was approved by the U.S. Supreme
Court in 2001. This amendment sustained the regime of the river by adhering to the original allocation of
the conservation pool. Wyoming and Nebraska contractors are limited to releases of 40,000 acre-feet on
an annual basis: 15,000 acre-feet to Wyoming and 25,000 acre-feet to Nebraska. Any storage not used
may be carried over as long as the total conservation pool does not exceed 100,000 acre-feet. Of the
15,000 acre-feet allocated to Wyoming, the USBR has long-term contracts for 4,400 acre-feet. Therefore,
Wyoming may contract for an additional 10,600 acre-feet of water, whenever available, to maximize the
beneficial use of Wyoming’s allocation of the conservation pool.
The 1996 stipulation expanded the use of Glendo storage water in Wyoming by allowing use for
any beneficial purpose whatsoever, rather than strictly limiting the use for irrigation purposes as
mandated by the 1953 Order. Further, as stipulated in 1996, Glendo storage water can be exchanged by
replacing 2 acre-feet for every acre-foot of natural flow withdrawn to support beneficial uses upstream of
the reservoir. The State of Wyoming has written to the USBR seeking to enter into a long-term contract
to purchase and remarket the remaining 10,600 acre-feet of Wyoming’s 15,000 acre-feet allocation to
maximize beneficial use. In the short term, the State of Wyoming proposes to include Wyoming’s
currently uncommitted 10,600 acre-feet of the state’s Glendo allocation to meet the replacement
obligations as described in the Modified North Platte Decree.
Snake/Salt River Basin
The Palisades Reservoir Contract provides Wyoming with 33,000 acre-feet or 2.75 percent of the
1,200,000 acre-feet of active storage space in Palisades Reservoir. Wyoming is entitled to the water
accruing to this space in priority for a variety of purposes, including the Snake River Compact
replacement storage space obligations, subcontracting the use of storage water to others, and maintaining
instream flows and lake levels within Wyoming through exchange. Wyoming is treated, for the most
part, like any other storage spaceholders in Palisades Reservoir under contract with the USBR, with the
same general rights and obligations for the use, accounting, and administration of the storage space.
Wind/Bighorn River Basin
In a 1985 agreement with the United States of America, covering the Buffalo Bill Dam
Modifications which raised the dam 25 feet and increased storage capacity, Wyoming acquired
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approximately 190,000 acre-feet of space from the 644,540 acre-feet total upsized capacity of Buffalo Bill
Reservoir. Wyoming and the USBR provide winter releases, beginning in October and ending with the
onset of the irrigation season, that range from a minimum of 100 cfs to a maximum of 350 cfs. During
normal and wet cycles the majority of the winter releases come from the Wyoming account. A maximum
winter release of 50 cfs accrues to the original reservoir before undertaking the Buffalo Bill Modifications
project. The actual release is dependent upon reservoir inflows and the amount of carry-over storage
remaining in Wyoming’s 190,000 acre-feet storage account. During periods of drought, the winter 100
cfs releases equally debit the Wyoming account and the USBR’s original storage space, which was
available before the Buffalo Bill Modifications project.
After winter releases are considered, Wyoming’s Buffalo Bill Reservoir account yields 20,000
acre-feet on a firm annual basis. Further, during normal and wet cycles, up to an additional 10,000 acrefeet
of water, whenever available, may be marketed for irrigation, municipal, or industrial purposes.
Before a water sale contract can be executed, the required NEPA review must be completed, and the
potential sale must first be approved by the WWDC and the Governor. As of the date of printing this
report, the State has not marketed any of its Buffalo Bill storage water.
3.3.4 Water Environmental Laws
The Environmental Quality Act was passed by the Wyoming Legislature in 1973. The purpose of
the law was to address the concern that pollution “will imperil public health and welfare, create public
and private nuisances, be harmful to wildlife, fish and aquatic life, and impair domestic, agricultural,
industrial, recreational and other beneficial uses.” The act authorized the state “to prevent, reduce and
eliminate pollution; to preserve, and enhance the water and reclaim the land of Wyoming; to plan
development, use, reclamation, preservation and enhancement of the air, land, and water resources of the
state; to preserve and exercise the primary responsibilities and rights of the state of Wyoming; to secure
cooperation between agencies of the state, agencies of other states, interstate agencies, and the federal
government in carrying out these objectives” (Wyoming Department of Environmental Quality Act,
1973).
The State of Wyoming has designated the Water Quality Division (WQD) of the Wyoming
Department of Environmental Quality (WDEQ) to oversee water quality and enforce the Environmental
Quality Act. This is being done through a number of programs that have been set up to control various
forms of potential pollution. Pollution can come from point and nonpoint sources and can affect surface
water and groundwater.
The WQD developed water quality standards which are documented in Chapter 1, Wyoming
Water Quality Rules and Regulations, and are available on the WQD website at
http://soswy.state.wy.us/rules/search.htm. The surface water quality standards are divided based on four
surface water classifications:
! Class 1, Outstanding Waters: Class 1 waters are surface waters in which no further water
quality degradation by point source discharges other than from dams will be allowed.
Nonpoint sources of pollution shall be controlled through implementation of appropriate best
management practices. Water quality and physical and biological integrity which existed on
the water at the time of designation will be maintained and protected. The designation of
Class 1 waters is reflective of water quality. This includes the following characteristics:
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aesthetically pleasing, scenic, recreational, ecological, agricultural, botanical, zoological,
municipal, industrial, historical, geological, cultural, archaeological, fish and wildlife habitat,
the presence of significant quantities of developable water, and other values of present and
future benefit to the people.
! Class 2, Fisheries and Drinking Water: Class 2 waters are waters, other than those
designated as Class 1, that are known to support fish or drinking water supplies or where
those uses are attainable. Class 2 waters may be perennial, intermittent or ephemeral and are
protected for the uses indicated in each subcategory.
! Class 3, Aquatic Life Other than Fish: Class 3 waters are waters, other than those
designated as Class 1, that are intermittent, ephemeral, or isolated and because of natural
habitat conditions, do not support have the potential to support fish populations or spawning;
Class 3 includes certain perennial waters which lack the natural water quality to support fish
(e.g., geothermal areas). Class 3 waters support invertebrates, amphibians, or other flora and
fauna which inhabit waters of the state at some stage of their life cycles. Uses designated on
Class 3 waters include aquatic life other than fish, recreation, wildlife, industry, agriculture,
and scenic value. Generally, waters suitable for this classification have wetland
characteristics, and such characteristics are a primary indicator used in identifying Class 3
waters.
! Class 4, Agriculture, Industry, Recreation and Wildlife: Class 4 waters are waters, other
than those designated as Class 1, where it has been determined that aquatic life uses are not
attainable. Uses designated on Class 4 waters include primary contact recreation, wildlife,
industry, agriculture, and scenic value.
Groundwater Quality
The State of Wyoming has identified the following standards for different classes of groundwater
(WDEQ, 2004):
! Class I groundwater is defined as groundwater suitable for domestic use.
! Class II groundwater is defined as groundwater suitable for agricultural use where soil
conditions and other factors are adequate.
! Class III groundwater is defined as groundwater suitable for stock use.
! Class Special (A) groundwater is defined as groundwater suitable for fish and aquatic life.
! Class IV groundwater is defined as groundwater suitable for industry.
! Class V groundwater is defined as groundwater found closely associated with commercial
deposits of hydrocarbons, or groundwater which is considered a geothermal resource.
! Class VI groundwater is defined as groundwater that may be unusable or unsuitable for use.
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Table 3-8 includes additional information regarding the standards for Classes I, II, and III.
Table 3-8 WDEQ Groundwater Quality Standards
Constituent
Class I
(domestic)
Class II
(agricultural)
mg/L
Class III
(livestock)
Chloride 250 100 2,000
Iron 0.3 5
Sulfate 250 200 3,000
TDS 500 2,000 5,000
SAR 1 8
1
Sodium Adsorption Ratio (SAR) has been found to be important with respect to use of
coalbed methane waters for irrigation.
The U.S. Environmental Protection Agency (USEPA) regulates public drinking water supplies in
Wyoming since the State has not assumed primacy for this Clean Water Act program. This program
provides comprehensive regulation of both surface and groundwater supplies, including enforceable
standards for organic and inorganic constituents, complex filtration and disinfection requirements for
surface water or groundwater determined to be under the influence of surface water, and monitoring and
reporting requirements to ensure compliance. Although these rules and regulations continue to evolve,
groundwater is widely considered to be a more desirable source of drinking water if it is available, due to
substantially less expensive compliance requirements. Table 3-9 provides a partial listing of the inorganic
constituents for which the USEPA has promulgated Maximum Contaminant Levels (MCL). “Primary”
standards are based on human health effects and are required to be met. “Secondary” standards are based
on the aesthetics of drinking water and are advisory.
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Table 3-9 Drinking Water Standards
MAJOR IONS (mg/L)
USEPA Maximum
Contaminent Level
Constituent (unit) Primary Secondary
Chloride 250
Fluoride 4 2
Nitrogen, Nitrate+Nitrite as N 10
Nitrogen, Nitrite as N 1
Sulfate 250
NON-METALS (mg/L)
Cyanide 0.2
PHYSICAL PROPERTIES
Color (color units) 15
Corrosivity (unitless)
non-corrosive
Odor (threshold odor number) 3
pH (standard units) 6.5 - 8.5
Total Dissolved Solids (mg/L) 500
Surfactants (methylene blue active substances) 0.5
METALS - TOTAL (mg/L)
Aluminum 0.05 - 0.2
Antimony 0.006
Arsenic 0.01
Barium 2
Beryllium 0.004
Cadmium 0.005
Chromium 0.1
Copper 1.3 1
Iron 0.3 0.3
Lead 0.015
Manganese 0.05
Mercury 0.002
Nickel 0.1
Selenium 0.05
Silver 0.1
Thallium 0.002
Uranium 0.03
Zinc 5
RADIONUCLIDES - TOTAL (pico Curies per liter)
Gross Alpha 15
Gross Beta 50
Radium 226 + Radium 228 5
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Chapter 8 of the Wyoming Water Quality Rules and Regulations addresses groundwater quality
standards and protection. These rules are enforced by the WDEQ (WDEQ, 2004). Chapter 8 describes
various classifications that have been created for groundwater and outlines the rules for discharges to
these waters. Additional information regarding groundwater quality can be found in the groundwater
characterization portion of Chapter 4 of this Framework Water Plan.
Surface Water Quality
The Clean Water Act requires that a 305(b) report be created which covers statewide water
quality, along with a 303(d) list, of impaired streams in the state. Impaired streams require the
establishment of total maximum daily loads (TMDLs) for problem pollutants. A TMDL is the amount of
a specific pollutant that a water body can receive and assimilate in a given time period and still meet
water quality standards.
The classification of a stream indicates what use is being or can be supported by that stream. In
general, the water quality in Wyoming is good based upon the number of water bodies supporting their
designated uses. Wyoming’s 305(b) State Water Quality Assessment Report produced by WDEQ
includes 303(d) listings.
3.3.5 Federal Environmental Laws
Numerous federal legislative efforts have authorized the remediation and protection of water
quality and the environment. These include the Clean Water Act, Pollution Prevention Act, Safe
Drinking Water Act, Clean Air Act, NEPA, Solid Waste Disposal Act, Toxic Substance Control Act, and
Federal Insecticide, Fungicide and Rodenticide Act. Most of the federal programs involved with water
quality allow individual states to obtain primacy to administer the federal programs. The USEPA can
step in if a state is not conducting the program to their satisfaction, even if the state has primacy.
The following is a list of water development and management actions that can initiate or trigger
federal environmental laws. A discussion of applicable federal legislation is presented following the list.
! Issuance and renewal of special use and right-of-way permits on federal lands.
! Contracting for storage water from federal reservoirs.
! Discharge of dredged and/or fill material into waters of the United States, including rivers, streams,
and wetlands.
! Procurement and renewal of licenses from the Federal Energy Regulatory Commission (FERC) to
produce hydropower.
! Use of federal loan or grant funds to construct a new water project or rehabilitate an existing water
project.
Key applicable federal legislation includes the following acts:
Endangered Species Act
The Endangered Species Act of 1973 (ESA) requires the Secretary of Interior, through the U.S.
Fish and Wildlife Service (USFWS), to determine whether wildlife and plant species are endangered or
threatened based on the best available scientific information. The ESA constrains all federal agencies
from taking any action that may jeopardize the continued existence of an endangered or threatened
3-29

3.0 SETTING
species. If a federal agency is considering an action that may jeopardize an endangered species, Section 7
of the ESA requires that the agency must consult with the USFWS.
National Environmental Policy Act
The National Environmental Policy Act of 1969 (NEPA) requires that federal agencies consider
all reasonable foreseeable environmental consequences of their proposed actions. A review of an action
under NEPA can be in the form of a simple finding of no significant impact (FONSI), environmental
assessment (EA), or an EIS and record of decision. Further, NEPA requires federal decision-makers to
“study, develop, and describe appropriate alternatives to recommended courses of action in any proposal
which involves unresolved conflicts concerning alternative uses of available resources” (42 USC 4321 et
seq., Sec. 102(2)E). NEPA provides federal agencies the opportunity to determine which alternative,
including no action, they feel best serves the applicant’s purpose and need. The alternative selected by
the federal agency may differ from the one preferred by the applicant.
Clean Water Act
Section 404 of the Clean Water Act of 1972 prohibits discharging dredged or fill materials into
waters of the United States without a permit from the USCOE. The waters of the United States include
rivers and streams and, as of 1993, wetlands. USCOE policy requires applicants for 404 permits to avoid
impacts to waters of the U.S. to the extent practicable, then minimize the remaining impacts, and finally
take measures to mitigate unavoidable impacts. In addition to the alternative review required by NEPA,
Section 404(b)(1) guidelines require an alternative review to define the least environmentally damaging
practicable alternative.
Section 401 of the Clean Water act provides that the State of Wyoming certify any federally
licensed or permitted facility which may result in a discharge into the waters of the state. The 401
certification provides a mechanism for Wyoming to amend, or perhaps veto, an action that the federal
agency might otherwise permit. While the 401 certifications are required for several federal actions, most
401 certifications relate to Section 404 Dredge and Fill Permits required from the USCOE.
3.4 REFERENCES
Collins, Gary. Office of the Tribal Water Engineer. 2000. Wind River Reservation Tour.
August.
(1969-1997).
Economic Analysis Division. 2006. Equality State Almanac.
Foulke, Coupal and Taylor. 2000. Trends in Wyoming Agriculture: Agriculture Employment
Jacobs, James J., and Donald J. Brosz. 2000. Wyoming’s Water Resources. University of
Wyoming, Agricultural Experiment Station. August.
Water Resources Data System. 2004. Wyoming Climate Atlas, Average Number of Frost Free
Days. http://www.wrds.uwyo.edu/wrds/wsc/climateatlas/title_page.html.
Wyoming Department of Environmental Quality. 1973. Environmental Quality Act.
3-30

3.0 SETTING
Wyoming Department of Environmental Quality, Water Quality Division. 2004. Wyoming Water
Quality Rules and Regulations, Chapter 8.
John Hopkins University, Applied Physics Laboratory. 1995. Shaded Relief Map of Wyoming.
http://fermi.jhuapl.edu/states/maps1/wy.gif.
3-31

WYOMING - Headwaters of the West!
Streams flow from Wyoming in all
directions to the major river systems
of the United States.
Major Drainage System
Missouri River Basin
Upper Colorado River Basin
Pacific Northwest River Basins
Great Basin
Percent of Wyoming
72
21
5
2
PACIFIC
NORTHWEST
RIVER BASINS
WYOMING
MISSOURI
RIVER BASIN
GREAT BASIN
UPPER
COLORADO
RIVER BASIN
LOWER
COLORADO
RIVER BASIN
3-32
"
Figure 3-1
Water Resource Regions

FRANNIE
RANCHESTER
DEAVER COWLEY
DAYTON
LOVELL
SHERIDAN
BYRON
POWELL
SHERIDAN
HULETT
PARK
BIG HORN
CLEARMONT
CROOK
CODY
GREYBULL
BURLINGTON
BASIN
MANDERSON
Powder/Tongue
PINE HAVEN
BUFFALO
GILLETTE
MOORCROFT
CAMPBELL
SUNDANCE
MEETEETSE
UPTON
TETON
Snake/Salt
JACKSON
Wind/Bighorn
TEN SLEEP
WORLAND
JOHNSON
WESTON
WASHAKIE
KIRBY
WRIGHT
KAYCEE
HOT SPRINGS
THERMOPOLIS
DUBOIS
Northeast
NEWCASTLE
FREMONT
MIDWEST
ALPINE
PAVILLION
SHOSHONI
RIVERTON
NIOBRARA
CONVERSE
THAYNE
NATRONA
HUDSON
ROLLING HILLS
PINEDALE
LANDER
GLENROCK
MILLS CASPER
MANVILLE
LUSK
AFTON
SUBLETTE
DOUGLAS
LOST SPRINGS
VAN TASSELL
BIG PINEY
GLENDO
LINCOLN
HARTVILLE
LA BARGE
GUERNSEY
BAIROIL
FORT LARAMIE
COKEVILLE
Green
Great Divide
Basin Platte
HANNA
MEDICINE BOW
WHEATLAND
PLATTE
LINGLE
GOSHEN
TORRINGTON
YODER
Bear
KEMMERER
OPAL
SUPERIOR
GRANGER
ROCK SPRINGS
SWEETWATER
GREEN RIVER
RAWLINS SINCLAIR
CHUGWATER
ROCK RIVER
ELK MOUNTAIN
ALBANY
LA GRANGE
WAMSUTTER
CARBON
SARATOGA
ALBIN
LYMAN
LARAMIE
EVANSTON
MOUNTAIN VIEW
UINTA
LARAMIE
BURNS PINE BLUFFS
ENCAMPMENT
CHEYENNE
BAGGS
DIXON
LEGEND
River Basin Planning Area Continental Divide
Note: The Great Divide Basin is a closed basin within the Green River Basin.
"
Figure 3-2
River Basin Planning Area Map
3-33

FRANNIE
DEAVER COWLEY
LOVELL
BYRON
POWELL
PARK
RANCHESTER
DAYTON
SHERIDAN SHERIDAN
BIG HORN
CLEARMONT
CAMPBELL
HULETT
CROOK
CODY
GREYBULL
BURLINGTON
BASIN
BUFFALO
Powder/Tongue
SUNDANCE
PINE HAVEN
Wind/Bighorn
GILLETTE
MOORCROFT
MANDERSON
UPTON
TETON
TEN SLEEP
WORLAND
JOHNSON
WESTON
WASHAKIE
HOT SPRINGS
KIRBY
WRIGHT
Northeast
NEWCASTLE
Snake/Salt
JACKSON
KAYCEE
THERMOPOLIS
DUBOIS
MIDWEST
FREMONT
ALPINE
PAVILLION
SHOSHONI
RIVERTON
NIOBRARA
CONVERSE
THAYNE
NATRONA
ROLLING HILLS
HUDSON
PINEDALE
GLENROCK
LANDER
MILLS CASPER
MANVILLE
SUBLETTE
LUSK
AFTON
DOUGLAS
LOST SPRINGS
VAN TASSELL
BIG PINEY
GLENDO
LINCOLN
LA BARGE
Green
HARTVILLE
GUERNSEY
BAIROIL
FORT LARAMIE
COKEVILLE
Bear
MEDICINE BOW
HANNA
KEMMERER
OPAL
RAWLINS
SUPERIOR
SINCLAIR
ROCK RIVER
Platte
PLATTE
WHEATLAND
CHUGWATER
LINGLE
GOSHEN TORRINGTON
YODER
CARBON ELK MOUNTAIN
LA GRANGE
WAMSUTTER
ALBANY
GRANGER
ROCK SPRINGS
GREEN RIVER
SWEETWATER
SARATOGA
ALBIN
LYMAN
UINTA LARAMIE
LARAMIE
EVANSTON
MOUNTAIN VIEW
BURNS PINE BLUFFS
ENCAMPMENT
CHEYENNE
BAGGS
DIXON
Private
LEGEND
State
Federal
"
Figure 3-3
Land Ownership by River Basin
3-34

3-35

3-36

PARK
Wind/Bighorn
Snake/Salt
CODY
FRANNIE
RANCHESTER
DEAVER COWLEY
DAYTON
SHERIDAN
20
22
MEETEETSE
LOVELL
BYRON
POWELL
BIG HORN
GREYBULL
BURLINGTON
BASIN
MANDERSON
SHERIDAN
TEN SLEEP
JOHNSON
WORLAND
TETON
CLEARMONT
Powder/Tongue
HULETT
CROOK
15
25
SUNDANCE
PINE HAVEN
BUFFALO
GILLETTE
MOORCROFT
CAMPBELL
UPTON
15
20
WASHAKIE
KIRBY
WRIGHT
KAYCEE
HOT SPRINGS
THERMOPOLIS
Northeast
NEWCASTLE
WESTON
15
JACKSON
DUBOIS
FREMONT
MIDWEST
ALPINE
PAVILLION
SHOSHONI
THAYNE
PINEDALE
AFTON
SUBLETTE
NIOBRARA
RIVERTON
CONVERSE
NATRONA
ROLLING HILLS
HUDSON
GLENROCK
LANDER
MILLS CASPER
MANVILLE
LUSK
DOUGLAS
LOST SPRINGS
14
VAN TASSELL
20
BIG PINEY
GLENDO
LINCOLN
Bear
COKEVILLE
Green
KEMMERER
OPAL
SUPERIOR
GRANGER
ROCK SPRINGS
SWEETWATER
GREEN RIVER
LYMAN
EVANSTON
MOUNTAIN VIEW
UINTA
LA BARGE
BAIROIL
RAWLINS SINCLAIR
WAMSUTTER
CARBON
SARATOGA
ENCAMPMENT
MEDICINE BOW
HANNA
ROCK RIVER
ELK MOUNTAIN
Platte
HARTVILLE
GUERNSEY
PLATTE
WHEATLAND
CHUGWATER
ALBANY
LARAMIE
LARAMIE
CHEYENNE
FORT LARAMIE
LINGLE
TORRINGTON
GOSHEN
YODER
20
17
LA GRANGE
ALBIN
BURNS PINE BLUFFS
18
16
17
20
18
LEGEND
Contour from 1973 Framework Water Plan
The values at individual Weather Bureau Stations are shown. The isolines are intended to show approximate
values for the areas represented by W.B. stations. Mountainous areas are not represented on this map.
BAGGS
DIXON
"
Figure 3-6
Average Seasonal Consumptive
Irrigation Requirements for Grass (In Inches)
3-37

3-38

4.0 RESOURCES
4.1 INTRODUCTION
This chapter presents the physical characteristics (quantity and quality) of Wyoming’s surface
water and groundwater. Regarding water quantity, the intent of the chapter is to characterize Wyoming’s
total hydrologically available water supply irrespective of existing uses, institutional constraints, and
visions for how water resources might be put to future beneficial use. In other words, this chapter
provides estimates for the volume of water Wyoming must draw upon to sustain itself and future
generations.
The results described herein pertain to physical availability, which is to be distinguished from
legal or permitted availability. Physical availability is important in assessing the viability of any future
project, and lack of physical availability of water is an obvious fatal flaw for any water development.
4.2 GENERAL
Wyoming is a headwaters state, and
precipitation is the source of most water in the
state. Figure 4-1 presents mean precipitation
rates. Approximately 68 million acre-feet per
year 1 of precipitation joins 1.5 million acrefeet
of surface inflows to create the total water
resource. The basic hydrologic cycle is
depicted in the margin graphic for a typical
Wyoming river basin. Most of the
precipitation will evaporate from the surface
or be taken up and transpired by local
vegetation. Figure 4-2 presents mean rates of
potential evapotranspiration. Precipitation
and snowmelt in excess of immediate
demands will either run off (feeding rivers,
streams, and lakes) or infiltrate to become
groundwater. Approximately 15 million acrefeet
per year of water become either surface or
Hydrologic Cycle
groundwater and thus available for use. This
estimate is made up of the water that flows into the state plus the precipitation that runs off as streamflow
or infiltrates as groundwater. Groundwater recharge will eventually return to the surface. Surface water
will eventually evaporate to the atmosphere, completing the cycle. These two elements of the total water
resource, surface water and groundwater, are the subject of the present report.
1 13.07 inches per year mean annual statewide precipitation rate (Wyoming Climate Atlas, 2004).
4-1

4.0 RESOURCES
4.3 SURFACE WATER RESOURCES
4.3.1 Quantity
The objective of this chapter is to present basin and statewide estimates
of total physically available water supply resources. A coarse estimate of those
volumes can be made by simply adding the quantity of surface water leaving the
state to estimates of surface water depletions. The estimates of water leaving the
state come directly from gaging station records shown on Figure 4-3. The
estimates for surface water depletions come from data in Chapter 5. Table 4-1
and Figure 4-4 present the estimated annual natural flows for the river basins.
Table 4-1 shows the streamflow that occurs in each of the river basins. The table
also shows the per-acre yield for each of the river basin planning areas. The
northwest corner of the state has the largest yield per acre while the northeast
corner of the state has the lowest yield per acre. Table 4-1 also shows the
changes that occur due to hydrologic conditions, wet, normal, and dry.
Approximately 17 million acre-feet run into Wyoming or are produced within the
state under normal conditions.
Table 4-1 Total Annual Flow 1,2,3
GREAT BASIN
River Basin
Area
Yield
Ratio Based on
Normal
Conditions Wet Normal Dry
acres 4 ac-ft/ac ac-ft ac-ft ac-ft
Bear River 960,000 0.55 888,000 526,000 234,000
COLORADO RIVER
Green River 13,440,000 0.19 3,746,000 2,617,000 1,543,000
MISSOURI RIVER
Northeast Wyoming 5 7,680,000 0.03 407,000 240,500 138,000
Powder/Tongue River 7,232,000 0.14 1,418,000 982,600 694,000
Platte River 6 15,424,000 0.08 2,249,000 1,307,000 1,105,000
Wind/Bighorn River 12,928,000 0.36 5,856,000 4,629,000 3,514,000
Yellowstone River 7 1,792,000 1.76 3,623,000 3,150,000 2,374,000
COLUMBIA RIVER
Snake/Salt River 8 3,264,000 1.08 5,047,000 3,540,000 2,179,000
Total 62,720,000 0.27 23,234,000 16,992,100 11,781,000
1 Estimates are based on outflow plus depletions from the current river basin plans.
2 Depletion estimates are from the current river basin plans.
3 Depleted flows are based on outflow estimates from the current river basin plans.
4
Basin areas do not total to the actual state area due to rounding and exclusion of small drainages in Yellowstone Park.
5
Excludes the flows for the Little Missouri and Niobrara Rivers.
6 The Platte River system is fully appropriated in that a water supply based on a water right with a current day priority cannot be expected to provide a reliable
supply due to water rights administration. Estimates exclude the flows and depletions from the Horse Creek and South Platte Drainages.
7 Drainage area is within Yellowstone National Park and includes estimates for the Madison, Gibbon, Firehole, and Gallatin Rivers.
8
Excludes the flows for the Henrys Fork and Teton Rivers.
4-2

4.0 RESOURCES
A major portion of the annual streamflows is made up of snowmelt runoff occurring during the
months of April, May, June, and July. Variations in snowfall and other forms of precipitation from year
to year affect average annual streamflows. Steamflow also varies considerably during the year. Figures 4-
5a and 4-5b show the seasonal and annual variation in flow of 14 streamflow gages, two in each basin.
These figures identify where water is available throughout the state. Three of the gages were selected to
show specific points related to streamflow.
Green River at the Warren Bridge gage was selected as it represents a stream with minimal
diversion and storage above the gage. The flow estimates are averages based on a 30-year period from
1970 to 2000. The average monthly flow of the Green River at Warren Bridge is 30,900 acre-feet.
Average monthly flows range from less than 10,000 acre-feet during the winter to over 100,000 acre-feet
in June. Figure 4-5b also shows the annual variation in flows at the Warren Bridge gage. Annual flows
vary from about 200,000 acre-feet to over 500,000 acre-feet.
Another gage that shows similar conditions is the North Platte River above Seminoe Reservoir.
Figure 4-5a shows the average monthly flow of 74,400 acre-feet. Monthly flows vary from under 25,000
acre-feet to over 250,000 acre-feet. Annual flow variation is from under 400,000 acre-feet per year to
almost 1,600,000 acre-feet per year. These figures show the natural flow variation that is typical of
Wyoming streams that are not controlled by large storage reservoirs or major diversions.
The impacts of reservoir storage and subsequent water delivery can be seen in the flows of the
North Platte River below Guernsey Reservoir. The average monthly flow is 106,800 acre-feet. Monthly
average flows vary throughout the year from near zero in the winter months to over 300,000 acre-feet in
July, the peak irrigation water delivery month. Annual average flow of the North Platte River below
Guernsey Reservoir is 1,281,000 acre-feet per year. Average annual flow varies from about 750,000
acre-feet to nearly 2,300,000 acre-feet per year. While flows here vary, the year-to-year variation is
controlled due to the large amount of upstream storage.
4.3.2 Water Quality
Water quality refers to physical, chemical, radiological, biological and bacteriological properties.
The concentration levels of various constituents dictates the uses and potential uses of a water body. In
some cases, institutional constraints on water quality (Chapter 3) control the potential use of water.
However, water quality also represents a basic, physical constraint on use. Table 4-2 summarizes the
basic suitability of water for various uses. Quality of a water body can be impacted by natural
environmental processes or by man-made actions. The success of a water development project is
dependent upon the ability of the resource to meet the water quality needs of the proposed use(s), as well
as the ability of the water development project to establish and maintain water quality. Where water use
is sufficiently valuable, of course, desirable quality can be established and maintained by treatment.
4-3

4.0 RESOURCES
Table 4-2 Recommended Guidelines for TDS in Irrigation Water
Total Dissolved Solids
(TDS) in mg/L
Guideline / Effects

4.0 RESOURCES
Tensleep Sandstone aquifer of the Bighorn Basin 2 . Groundwater flow is from the basin margins toward
the center and, ultimately, to the north, like the surface drainage.
Figure 4-8 presents typical annual cycles of groundwater levels, in this example from a 110-foot
deep well in an area of active irrigation. It reflects: 1) a pronounced drop in water level each spring, as
irrigation pumping starts; 2) an initially rapid, then slower, recovery of water levels through the fall and
winter as the aquifer is recharged from surrounding areas and the surface; and 3) overall multiyear
fluctuations in the recovered water levels in response to varying irrigation management and climatic
patterns.
In areas away from the influence of irrigation withdrawals, groundwater levels commonly rise in
response to spring precipitation and snowmelt, and fall to annual lows in midwinter due to the absence of
recharge. In aquifers remote from surface influence, there may be little or no annual fluctuation, but
groundwater levels may rise and fall in response to long-term climate cycles. Individual well
hydrographs vary widely, as a function of local hydrogeologic and groundwater development conditions.
4.4.2 Aquifer Classification
Classification of a body of geologic material as an “aquifer” depends on how much water is
needed for a specific user or purpose. A hydrogeologic formation capable of adequately supplying the
modest water needs of a single rural residence may be entirely inadequate to meet the needs of a large
agricultural operation.
Figure 4-9 presents a hydrogeologic map of Wyoming. Approximately 210 individual geologic
formations have been combined into six general groups based on the classifications and descriptions in
the seven Basin Plans 3 . The figure also presents a narrative summary, including reference to the
individual formations 4 within each group.
These classifications are highly generalized, because geologic materials are rarely entirely
consistent over large areas. For example, the Madison Limestone (in the “Major Aquifer - Limestone”
group) is famous for producing flowing wells of phenomenal productivity at certain Wyoming locations,
but in the absence of fractures and solution features will produce very little. Conversely, the Cody Shale
(in the “Major Aquitard” group) is universally understood to be a regional confining unit, but it can
produce modest quantities of water from local sandstone beds. Regional changes in formation
characteristics cause some formations to be classified differently in different basins.
Thickness, yield, and groundwater quality data in Figure 4-9 are bracketed by data from the listed
basins, so may span a wider range than in any one basin. Considerable additional detail on the
characteristics and variations within each aquifer is generally available in the individual basin reports.
The thickness ranges listed are for the formations themselves and do not reflect depths of
occurrence. While most water wells in Wyoming are less than 200 feet deep, wells as deep as 6,000 feet
have encountered useful supplies of good-quality groundwater.
2 Figure 4-7 is from the Wind/Bighorn Basin Plan.
3 The individual plans did not use consistent terminology or formation grouping. The designations used here are compiled/interpreted from the plans’
mapping, tabular, and narrative information.
4 To provide a consistent, statewide formation taxonomy, Figure 4-9 uses formation symbols from the standard, USGS “Geologic Map of Wyoming”
(1985), which is available either in printed form from the Wyoming Geological Survey (www.wsgs.uwyo.edu/) or electronically from
http://www.wygisc.uwyo.edu/24k/bedgeol.html.
4-5

4.0 RESOURCES
Major Aquifers
Alluvial
The most consistently productive aquifers in Wyoming are the alluvial sands and gravels
associated with many of Wyoming’s streams and rivers. The most productive area is along the Snake
River west of Jackson, where the aquifer does not contain much silt or clay and is over 2,000 feet thick.
Elsewhere in the state, the alluvial aquifer rarely exceeds 100 feet in thickness, but, under favorable
conditions, can produce well yields on the order of 500-1,000 gallons per minute (gpm).
Alluvial deposits are unproductive where silt and clay are abundant. In some areas, although the
alluvium is coarse-grained, it is relatively thin and sits above the groundwater table.
Where the alluvial aquifer is associated with an active stream, either interception of groundwater
headed for the stream or induced infiltration from the stream may provide most of the available
groundwater; stream depletion rates may approach pumping rates over relatively short time periods.
Where closely associated with surface streams, alluvial aquifer quality tends to be good due to the low
salinity of water in the stream and the filtering effect of the aquifer.
Sandstone
These aquifers are consolidated rock formations, sandstones and conglomerates, that are
commonly productive for groundwater. However, most of the deposits and formations in this group
include zones of poor production, due, for example, to local clay content or lack of fractures.
In the basin interiors, the sandstone aquifers tend to be widespread and horizontal or gently
dipping. In some cases, individual sandstone beds are thick and widespread such as the Cloverly
(Dakota) Sandstone. More commonly, however, groundwater production from these aquifers is a
function of discontinuous sandstone layers and lenses, requiring penetration of a substantial number of
individual beds to accumulate the desired amount of water. Examples include the Ogalalla (southeast),
Wasatch (northeast), and Wind River (central) Formations. Particularly in the Powder River Basin, coal
beds within these aquifers can provide substantial, widespread groundwater productivity.
Adjacent to Wyoming’s mountain ranges, the older sandstone aquifers commonly dip into the
basin and may provide useful water supplies for miles basinward of the outcrop areas shown in Figure 4-
9. Examples include the Mesaverde, Cloverly, and Nugget Formations. The most productive formations
of this group are the thick, Tertiary-age sandstones of westernmost Wyoming, where local faulting and
fracturing are the key to productivity.
Groundwater quality tends to decrease with depth. High fluoride levels have been encountered in
the Lance and Fox Hills Formations.
Limestone
These aquifers are consolidated rock formations: limestones and dolomites. They are the primary
aquifers of the older, Paleozoic-age geologic section. Examples include the Madison Limestone, the
Casper Formation, and the Bighorn Dolomite. The most productive well in Wyoming is a flowing well in
the Madison Formation north of Worland, producing over 10,000 gpm of drinking-quality water.
Productivity at this location is a function of fracturing and solution features at the crest of the Paintrock
Anticline.
These are the most widespread Wyoming aquifers, present in all seven basins, but are generally
too deeply buried to be useful away from the mountain fronts. The productivity of these aquifers is
4-6

4.0 RESOURCES
almost entirely dependent upon fractures and solution features, created by deformation and groundwater
circulation, respectively, both of which processes are most well developed along the basin margins. More
than with any other major aquifers, local conditions are the key to successful groundwater development.
Minor Aquifers
These formations are typically thinner, less extensive, and/or less productive than the “major”
aquifer groups, but commonly provide useful groundwater supplies for local use. Productivity is largely a
function of the thickness and texture of sandstone units, although fracture enhancement of permeability
can make the difference between unacceptable and acceptable production rates. Modest yields (500 gpm) productivity around LaGrange and Pine Bluffs.
Major Aquitards
These formations are typically poorly productive of groundwater, and the groundwater is
commonly of poor quality. These formations are mostly thick marine shales, commonly described with
terms like “regional confining layer”. Because of their clay content, these rocks are less brittle than
sandstone or granite so are generally less subject to fracture enhancement of permeability. Examples
include the Pierre and Cody Shales.
These are some of thickest and most widespread formations in Wyoming. Isolated zones produce
small quantities of water at some locations-for example, the Muddy Sandstone member of the
Thermopolis Formation. However, groundwater from these formations is generally scarce and of poor
quality.
The crystalline rocks (granite, gniess, metamorphics, etc.) which underlie all of Wyoming are
included in this group because in the absence of fractures they are virtually impermeable. These rocks
form the lower limit to groundwater circulation in most cases. Nonetheless, these rocks may develop
useful fracture permeability due to stress changes near the surface or along faults. Where groundwater
can be produced, it tends to be of good quality.
Unclassified
These are geologic materials of limited occurrence for which insufficient data are available to
4-7

4.0 RESOURCES
suggest an aquifer grouping.
Aquifer Location
Figure 4-9 shows
where the indicated aquifer
group is present at the
surface. This is where the
aquifer is shallowest and
has the best quality, due to
the proximity to recharge.
As shown schematically to
the right, formations that
outcrop around the basin
margins commonly dip
beneath younger formations
present in the basin centers.
Thus, groundwater is
Cross-Section of Aquifer Types
commonly available from
productive basin-margin aquifers for some miles basinward of the outcrops depicted on Figure 4-9, albeit
at increasing depth.
Where a productive aquifer is overlain by less permeable strata, artesian conditions are set up
which may produce flowing wells where the less permeable strata are punctured. Wyoming examples
include prolific flowing wells on the flanks of the Black Hills and Bighorn Mountains. While the basinbounding
aquifers are generally present beneath the entire basin, their great depth, the absence of the
basin-bounding fractures that enhance productivity, and the commonly deteriorated water quality make
them poor development targets in the central basins.
For all but the alluvial aquifers, geologic structure (folds and faults) is as important as rock type
in providing useful supplies of groundwater. The map to the right shows the major geologic faults in
Wyoming, which provide a generalized picture of where fracturing may be an important component of
groundwater productivity. In the Thrust Belt of western Wyoming and bordering the major mountain
ranges, large-scale faulting is a controlling factor in nearly any bedrock aquifer. Across most of eastern
Wyoming and in the basin interiors, in contrast, large-scale fracturing is much less important, and the
grain size and cementing of aquifer materials play the key role.
Finally, in the carbonate aquifers (limestone and
dolomite), the rocks themselves are slightly soluble, and
groundwater circulation can increase the size and extent of
fractures through dissolution. This is dramatically expressed in
the creation of cave systems, but can vastly enhance
groundwater production capacity at much finer scales. Faults,
folds, and solution enhancement of permeability are most
commonly associated with the basin margins, where
deformation of the formations has accompanied mountain
building.
Faults
4-8

4.0 RESOURCES
In summary, optimum conditions for the development of groundwater reflect the conjunction of
favorable formations, favorable permeability conditions within those formations – primarily coarsegrained
zones and/or fractures, and recharge conditions that provide suitable groundwater quality.
4.4.3 Historical Aquifer Performance
Economically developable groundwater has been found across much of the Wyoming landscape.
Figure 4-10 displays all water wells for which the permitted yield is greater than zero, excluding coalbed
methane (CBM) wells (discussed below). Thinly populated areas of the map reflect either a lack of
demand such as in the Red Desert or a lack of even small quantities of water from some of the “major
aquitards” such as northwest of Casper. In some areas of Wyoming, useful groundwater is simply not
present.
Highlighted on Figure 4-10 are all wells with permit yields of 500 gpm or greater. The
distribution is a function of aquifer performance. Most conspicuous is the coincidence with the alluvial
aquifer, reflecting both the commonly favorable conditions of permeability, depth, and quality, and the
concentration of agricultural and municipal demands in Wyoming’s stream valleys.
4.4.4 Groundwater Quality
Included on Figure 4-9 are general ranges of total dissolved solids (TDS) reported for the various
formations. As with yield, the broad ranges of aquifer TDS result from widely varying conditions across
basins. TDS is a generalized parameter of water quality, reflecting the total presence of dissolved
minerals. For example, a TDS concentration of 500 mg/l is considered the limit of aesthetically
acceptable human drinking water; 2,000 mg/l is a common maximum for irrigation water; and 5,000 mg/l
is considered the limit for livestock use. Maximum groundwater TDS values of 200,000 mg/l have been
reported from deep, oil field water wells.
The alluvial aquifers primarily receive recharge from an overlying stream (or irrigation
applications) and/or the surrounding geologic materials. Where the former dominates, groundwater
quality is generally good. The aquifer sands and gravels tend to filter sediment and bacteria from the
surface source to produce water that is clean and of low salinity. Where there is substantial inflow to the
alluvial aquifer from bedrock, alluvial groundwater quality will reflect that of the surrounding formations.
This water will commonly be higher in salinity than the surface water and may render the alluvial aquifer
of limited value for many applications.
Bedrock aquifers receive recharge through the infiltration of rainfall, snowmelt, and streamflow
although discharge from groundwater to streams is more common than the other way around.
Groundwater developed close to the areas of recharge may be of relatively high quality, regardless of the
host formation. As water moves deeper, it generally becomes more mineralized. Near outcrops,
groundwater is most commonly of a calcium bicarbonate type. Deeper, toward the basin centers, sodium
commonly increases relative to calcium, and sulphate and chloride dominate over bicarbonate.
In general, groundwater quality tends to be better in the more productive aquifers because of the
more active groundwater circulation and less soluble minerals. While even the “major” aquifers of Figure
4-9 may yield poor quality (particularly in deeper, central basin locations), they are more likely to provide
acceptable quality than the “marginal” aquifers or aquitards. The latter group has notoriously poor
quality, due to the coincident deposition of fine-grained materials (shale) and soluble minerals. An
exception is the crystalline rocks (last entry of Figure 4-9) in which quality is generally good due to the
4-9

4.0 RESOURCES
very low solubilities of the constituent minerals.
Where aquifers receive recharge from the surface, they are potentially subject to contamination.
In 1998, the University of Wyoming completed a statewide study of groundwater contamination potential
that assessed seven factors, including depth to groundwater and recharge rates, to produce 1:100,000 scale
county-by-county maps. Figure 4-11 presents a statewide version of this mapping of “Aquifer
Sensitivity”. Rankings are relatively-high, medium, and low and carry no specific units. The most
sensitive lands are those where a contaminant at the surface such as a spill, overapplication of agricultural
chemicals, or septic systems can most easily enter the aquifer. The alluvial aquifers are most sensitive.
Least sensitive are bedrock aquifers where substantial thicknesses of low-permeability material lie above
them.
The Snake/Salt Basin Plan extended the vulnerability concept to rural septic systems, a common
source of nitrate input to groundwater. The density of rural domestic wells was mapped, looking to a
general, rule-of-thumb of 2 acres/lot (20 lots per quarter-quarter section) as the threshold beyond which
septic system contamination may be of concern.
4.4.5 Groundwater Associated with Energy Development
For many decades, groundwater has been produced along with oil and gas from Wyoming’s
relatively “wet” oilfields. For example, in the Wind/Bighorn Basin, annual production of 331 ac-ft of coproduced
groundwater was estimated (WOGCC, 2000). This water has been discharged to the surface as
a by-product of mineral production; used for oil field water flood; or, due to increasing environmental
concerns, reinjected.
Starting in the 1990s, the production of groundwater in association with mineral production has
vastly increased through the development of CBM wells. Unlike the groundwater produced incidentally
with oil and conventional gas production, groundwater production is the driving force in CBM.
Groundwater production on the order of 5-15 gpm per well is used to lower groundwater pressure to bring
dissolved and adsorbed methane into the well. The produced water is typically discharged to the surface,
although water quality concerns are generating increasing consideration of reinjection. Figure 4-12
presents State Engineer’s Office permitted CBM wells as of December, 2006. Obviously, the Powder
River Basin has been the focus of activity to date. Development is far from complete in that basin and
has recently been extending to other basins. Because CBM accompanies coal seams and coal seams are
present in all Wyoming basins, there is potential for CBM development throughout the state. Permitting
activity beyond the Powder River Basin is just beginning and is expected to grow considerably in the near
future.
Wyoming has limited potential for groundwater geothermal energy development. Various sites
with low-grade geothermal resources have developed commercial applications through spa-type uses.
The Snake/Salt Basin Plan discusses the potential for development of the higher-grade geothermal
potential of far western Wyoming.
4.5 REFERENCES
Colorado Geological Society. 2003. Ground Water Atlas of Colorado.
Curtis, Jan, and Grimes, Kate. 2004. Wyoming Climate Atlas.
Love and Christiansen. 1985. Geologic Map of Wyoming.
Wyoming Oil and Gas Conservation Commission. 2000. 2000 Wyoming Oil and Gas Statistics.
4-10

4-11

4-12

#
# # #
#
# #
AFTON
#
#
#
ALPINE
THAYNE
#
##
#
# #
#
#
COKEVILLE
#
##
#
# # #
#
#
# #
# #
JACKSON
# # ##
# #
### #
Snake/Salt
LINCOLN
TETON
#
#
#
# # #
#
# # #
PINEDALE
# # ### #
# SUBLETTE # #
#
# # # #
#
#
FRANNIE
##
# #
# #
###
DEAVER COWLEY
#
LOVELL
#
#
#
#
# BYRON
# # POWELL
PARK
#
# # # ##
#
# # ### BIG HORN
CODY
GREYBULL
##
#
# # BURLINGTON
# #
BASIN
# #
Wind/Bighorn
MANDERSON
# #
# ##
##
# # MEETEETSE
# # # ## # WORLAND
##
#
HOT SPRINGS #
# # WASHAKIE
#
DUBOIS #
#
#
# # #
# #
# # # #
#
MARBLETON
BIG PINEY
#
# #
#
#
#
#
#
LA BARGE
# #
# #
#
# # #
#
#
#
#
#
#
#
# ##
# ##### ##
RIVERTON
# # # # # #
HUDSON
##
# # # # #
PAVILLION # #
#
### # # FREMONT
#
# #
#
## ### # ## # # # #
# #
#
#
#
#
#
#
#
###
#
# ## #
# #
#
#
#
#
#
#
#
#
#
# #
SHERIDAN
SHERIDAN Powder/Tongue
##
CLEARMONT
# #
#
# # #
# #
# #
##
#
# BUFFALO
# #
#
#
#
# #
#
#
## ##
##
##
# # #
# # ##
KEMMERER ##
OPAL
#
RAWLINS SINCLAIR
Green
Bear
CARBON
WAMSUTTER
# GRANGER
#
# #
#
#
# #
#
#
# # # ##
ROCK SPRINGS
SWEETWATER
#
# # ## GREEN RIVER
#
SARATOGA
### #
# # # #
LYMAN
UINTA
EVANSTON
MOUNTAIN # VIEW
## #
# # # # #
ENCAMPMENT
#
#
#
##
#
# # #
# #
# #
BAGGS
# # DIXON
# # # #
# # # #
# ###
# #
# #
LEGEND #
# # #
#
# USGS Streamflow Gage
All active and inactive USGS gages are shown.
LANDER
KIRBY
THERMOPOLIS
SHOSHONI
BAIROIL
TEN SLEEP
RANCHESTER
DAYTON
#
#
NATRONA
#
#
JOHNSON
KAYCEE
# #
# #
#
# # MILLS
#
HANNA
##
#
#
#
# #
#
MIDWEST
CASPER
#
#
##
# #
# ELK MOUNTAIN
"
#
#
#
#
##
#
MEDICINE BOW
#
#
##
#
# #
#
#
#
CAMPBELL
#
#
# # CONVERSE
# # # ## #
# # #
DOUGLAS
ROLLING HILLS
GLENROCK
ROCK RIVER
#
## ##
# #
#
# ## # ## PINE HAVEN
#
MOORCROFT
#
# ### UPTON
# # GUERNSEY
#
# # ## # FORT
#
LARAMIE
LINGLE
PLATTE
#
#
GOSHEN
# # #
TORRINGTON
WHEATLAND
#
# #
# ## # #
YODER
Platte
#
CHUGWATER
#
#
LA
#
GRANGE
# ###
# #
ALBIN
#
#
LARAMIE
LARAMIE # #
ALBANY
#
GILLETTE
#
# ## #
Northeast
# # #
#
# # #
#
# #
#
LOST SPRINGS
#
GLENDO
# # # # #
## # #
HULETT
# # # #
CROOK
WESTON
### #
CHEYENNE
SUNDANCE
#
#
NEWCASTLE
#
# ##
#
# # # # NIOBRARA
MANVILLE
HARTVILLE
LUSK
BURNS
#
VAN TASSELL
PINE BLUFFS
Figure 4-3
USGS Streamflow Gage Locations
#
###
4-13

Tongue River
Clarks Fork
Belle Fourche River
Clear Creek
Shos hone River
Yellowstone River
Powder River
Snake/Salt
TETON
PARK
Wind/Bighorn
FRANNIE
LOVELL
BYRON
POWELL
BIG HORN
CODY
GREYBULL
BURLINGTON
BASIN
MANDERSON
MEETEETSE
WORLAND
HOT SPRINGS
COWLEY
KIRBY
THERMOPOLIS
SHERIDAN
SHERIDAN
BUFFALO
TEN SLEEP
JOHNSON
WASHAKIE
CLEARMONT
Powder/Tongue
CAMPBELL
GILLETTE
Northeast
PINE HAVEN
CROOK
SUNDANCE
MOORCROFT
UPTON
WESTON
NEWCASTLE
Wind River
Snak e River
ALPINE
JACKSON
Platte River
THAYNE
PINEDALE
SUBLETTE
AFTON
DUBOIS
PAVILLION
SHOSHONI
FREMONT RIVERTON
NATRONA
HUDSON
LANDER
MIDWEST
NIOBRARA
ROLLING HILLS CONVERSE
GLENROCK
CASPER
MANVILLE
LUSK
DOUGLAS
LOST SPRINGS
VAN TASSELL
MARBLETON
BIG PINEY
GLENDO
Sweetwater River
Platte
Medicine Bow River
Green
Green River
Bear
LINCOLN
LA BARGE
COKEVILLE
GRANGER
ROCK SPRINGS
SWEETWATER
GREEN RIVER
LYMAN
UINTA
MOUNTAIN VIEW
BAIROIL
HANNA
RAWLINS SINCLAIR
ROCK RIVER
CARBON ELK MOUNTAIN
WAMSUTTER
SARATOGA
ENCAMPMENT
PLATTE
WHEATLAND
CHUGWATER
ALBANY
LARAMIE
LARAMIE
CHEYENNE
LINGLE
GOSHEN TORRINGTON
YODER
LA GRANGE
ALBIN
Little Snake River
Bear River
EVANSTON
KEMMERER
OPAL
HARTVILLE
GUERNSEY
FORT LARAMIE
BURNS PINE BLUFFS
LEGEND
0.01 4 million ac-ft
"
Figure 4-4
Average Annual Streamflow
4-14

Wind River Below Boysen Reservoir
Bighorn River at Kane
Tongue River Near Dayton
Powder River at Arvada
350,000
350,000
350,000
350,000
300,000
300,000
300,000
300,000
Streamflow (ac-ft)
250,000
200,000
150,000
100,000
50,000
Average Monthly Flow
=89,900 ac-ft
Streamflow (ac-ft)
250,000
200,000
150,000
100,000
50,000
Average Monthly Flow
=135,900 ac-ft
Streamflow (ac-ft)
250,000
200,000
150,000
100,000
50,000
Average Monthly Flow
=10,600 ac-ft
Streamflow (ac-ft)
250,000
200,000
150,000
100,000
50,000
Average Monthly Flow
=17,400 ac-ft
0
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
0
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
0
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
0
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Month
Month
Month
Month
Snake River Near Moran
Belle Fourche River at Wyoming-South Dakota State Line
350,000
350,000
Streamflow (ac-ft)
300,000
250,000
200,000
150,000
100,000
50,000
0
Average Monthly Flow
=91,400 ac-ft
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Month
Salt River Above Reservoir Near Etna
TETON
#
PARK
FRANNIE
DEAVER COWLEY
LOVELL
BYRON
POWELL
Wind/Bighorn
#
BIG HORN
CODY
GREYBULL
BURLINGTON
MEETEETSE
BASIN
MANDERSON
WORLAND
TEN SLEEP
#
RANCHESTER
DAYTON
SHERIDAN
SHERIDAN
CLEARMONT
WASHAKIE
JOHNSON
HOT SPRINGS
KIRBY
KAYCEE
#
Powder/Tongue
CAMPBELL
GILLETTE
WRIGHT
#
PINE HAVEN
MOORCROFT
HULETT
CROOK
SUNDANCE
Northeast
#
UPTON
WESTON
NEWCASTLE
Streamflow (ac-ft)
300,000
250,000
200,000
150,000
100,000
50,000
0
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Month
Belle Fourche River Below Moorcroft
Average Monthly Flow
=6,100 ac-ft
Streamflow (ac-ft)
350,000
300,000
250,000
200,000
150,000
100,000
50,000
Average Monthly Flow
=50,400 ac-ft
#
ALPINE
THAYNE
Snake/Salt
JACKSON
#
PINEDALE
AFTON
SUBLETTE
DUBOIS
THERMOPOLIS
#
PAVILLION
SHOSHONI
RIVERTON
FREMONT
HUDSON
LANDER
NATRONA
MIDWEST
MILLS CASPER
ROLLING HILLS
GLENROCK
CONVERSE
DOUGLAS
NIOBRARA
MANVILLE
LOST SPRINGS
LUSK
VAN TASSELL
3 X Streamflow (ac-ft)
350,000
300,000
250,000
200,000
150,000
100,000
50,000
Average Monthly Flow
=1,500 ac-ft
Streamflow (ac-ft)
0
350,000
300,000
250,000
200,000
150,000
100,000
50,000
0
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Month
Bear River Below Smiths Fork
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Month
Average Monthly Flow
=29,400 ac-ft
#
COKEVILLE
BIG PINEY
LINCOLN
LA BARGE
Bear
#
KEMMERER
OPAL
#
GRANGER
LYMAN
UINTA
EVANSTON
MOUNTAIN VIEW
GREEN RIVER
Green
SWEETWATER
ROCK SPRINGS
WAMSUTTER
BAIROIL
BAGGS DIXON
#
MEDICINE BOW
HANNA
Platte
RAWLINS SINCLAIR
ROCK RIVER
CARBON ELK MOUNTAIN
ALBANY
SARATOGA
LARAMIE
ENCAMPMENT
GLENDO
#
HARTVILLE
GUERNSEY
FORT LARAMIE
LINGLE
PLATTE
TORRINGTON
WHEATLAND
GOSHEN
YODER
CHUGWATER
LA GRANGE
"
ALBIN
LARAMIE
BURNS PINE BLUFFS
CHEYENNE
Streamflow (ac-ft)
0
350,000
300,000
250,000
200,000
150,000
100,000
50,000
0
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Month
North Platte River Below Guernsey
Average Monthly Flow
=106,800 ac-ft
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Month
Bear River Near Utah-Wyoming State Line
Green River Below Fontenelle Reservoir
Green River at Warren Bridge
North Platte River Above Seminoe
Streamflow (ac-ft)
350,000
300,000
250,000
200,000
150,000
100,000
50,000
0
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Month
Average Monthly Flow
=12,200 ac-ft
Streamflow (ac-ft)
350,000
300,000
250,000
200,000
150,000
100,000
50,000
0
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Month
Average Monthly Flow
=101,600 ac-ft
Streamflow (ac-ft)
350,000
300,000
250,000
200,000
150,000
100,000
50,000
0
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Month
Average Monthly Flow
=30,900 ac-ft
Streamflow (ac-ft)
350,000
300,000
250,000
200,000
150,000
100,000
50,000
0
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Month
Average Monthly Flow
=74,400 ac-ft
LEGEND
# USGS Streamflow Gage
Figure 4-5a
Monthly Streamflow Variation
4-15

Wind River Below Boysen Reservoir
Bighorn River at Kane
Tongue River Near Dayton
Powder River at Arvada
2,500
2,500
2,500
2,500
2,000
2,000
Average Annual Flow
=1,634,300 ac-ft
2,000
2,000
Streamflow (1,000 ac-ft)
1,500
1,000
500
Snake River Near Moran
0
1970
1972
1974
1976
1978
1980
1982
1984
1986
Year
Average Annual Flow
=1,082,000 ac-ft
1988
1990
1992
1994
1996
1998
2000
Streamflow (1,000 ac-ft)
1,500
1,000
500
0
1970
1972
1974
1976
1978
1980
1982
1984
1986
Year
1988
1990
1992
1994
1996
1998
2000
Streamflow (1,000 ac-ft)
1,500
1,000
500
0
1970
1972
1974
1976
1978
1980
1982
1984
1986
Year
Average Annual Flow
=127,100 ac-ft
1988
1990
1992
1994
1996
1998
2000
Streamflow (1,000 ac-ft)
1,500
1,000
500
0
1970
1972
1974
1976
1978
1980
1982
1984
Average Annual Flow
=208,900 ac-ft
1986
Year
1988
1990
1992
1994
1996
1998
2000
Belle Fourche River at Wyoming-South Dakota State Line
2,500
2,500
Streamflow (1,000 ac-ft)
2,000
1,500
1,000
500
0
2,500
2,000
1970
1972
1974
1976
1978
1980
1982
1984
1986
Year
Average Annual Flow
=1,094,900 ac-ft
Salt River Above Reservoir Near Etna
1988
1990
1992
1994
1996
1998
2000
TETON
#
Snake/Salt
JACKSON
PARK
DUBOIS
FRANNIE
DEAVER COWLEY
LOVELL
BYRON
POWELL
Wind/Bighorn
#
BIG HORN
CODY
GREYBULL
BURLINGTON
MEETEETSE
#
BASIN
MANDERSON
WORLAND
TEN SLEEP
#
RANCHESTER
DAYTON
SHERIDAN
SHERIDAN
CLEARMONT
WASHAKIE
JOHNSON
HOT SPRINGS
KIRBY
KAYCEE
THERMOPOLIS
#
Powder/Tongue
MIDWEST
CAMPBELL
GILLETTE
WRIGHT
#
PINE HAVEN
MOORCROFT
HULETT
CROOK
SUNDANCE
Northeast
#
UPTON
WESTON
NEWCASTLE
Streamflow (1,000 ac-ft)
2,000
1,500
1,000
500
0
2,500
2,000
1970
1972
1974
1976
1978
1980
1982
1984
Average Annual Flow
=72,800 ac-ft
1986
Year
Belle Fourche River Below Moorcroft
1988
1990
1992
1994
1996
1998
2000
Streamflow (1,000 ac-ft)
Streamflow (1,000 ac-ft)
1,500
1,000
500
0
2,500
2,000
1,500
1,000
500
0
1970
1972
1970
1972
1974
1974
1976
1978
1980
1982
1984
1986
Year
Bear River Below Smiths Fork
1976
1978
1980
1982
1984
Year
Average Annual Flow
=604,800 ac-ft
1988
1990
1992
1994
1996
1998
2000
Average Annual Flow
=350,700 ac-ft
1986
1988
1990
1992
1994
1996
2000
Bear River Near Utah-Wyoming State Line
#
THAYNE
#
ALPINE
Bear
#
#
AFTON
SUBLETTE
BIG PINEY
LINCOLN
COKEVILLE
KEMMERER
OPAL
LA BARGE
#
PAVILLION
RIVERTON
FREMONT
HUDSON
PINEDALE
LANDER
Green
GRANGER
SWEETWATER
ROCK SPRINGS
GREEN RIVER
LYMAN
UINTA
EVANSTON
MOUNTAIN VIEW
Green River Below Fontenelle Reservoir
SHOSHONI
WAMSUTTER
CONVERSE
NATRONA
ROLLING HILLS
GLENROCK
MILLS CASPER
DOUGLAS
BAIROIL
#
MEDICINE BOW
HANNA
Platte
RAWLINS SINCLAIR
ROCK RIVER
CARBON ELK MOUNTAIN
ALBANY
SARATOGA
LARAMIE
ENCAMPMENT
BAGGS DIXON
Green River at Warren Bridge
NIOBRARA
MANVILLE
LOST SPRINGS
LUSK
VAN TASSELL
GLENDO
#
HARTVILLE
GUERNSEY
FORT LARAMIE
LINGLE
PLATTE
TORRINGTON
WHEATLAND
GOSHEN
YODER
CHUGWATER
LA GRANGE
"
ALBIN
LARAMIE
BURNS PINE BLUFFS
CHEYENNE
North Platte River Above Seminoe
Streamflow (1,000 ac-ft)
Streamflow (1,000 ac-ft)
1,500
1,000
500
0
2,500
2,000
1,500
1,000
500
0
1976
1970
1978
1972
1980
1974
1982
1986
1991
1993
Year
1995
Average Annual Flow
=19,800 ac-ft
1997
North Platte River Below Guernsey
1976
1978
1980
1982
1984
Year
1986
1988
1999
1990
2001
1992
1994
2003
Average Annual Flow
=1,281,100 ac-ft
1996
2005
Streamflow (1,000 ac-ft)
2,500
2,000
1,500
1,000
500
0
1970
1972
1974
1976
1978
1980
1982
1984
1986
Year
Average Annual Flow
=146,400 ac-ft
1988
1990
1992
1994
1996
1998
2000
Streamflow (1,000 ac-ft)
2,500
2,000
1,500
1,000
500
0
1970
1972
1974
1976
1978
1980
1982
1984
1986
Year
Average Annual Flow
=1,218,600 ac-ft
1988
1990
1992
1994
1996
1998
2000
Streamflow (1,000 ac-ft)
2,500
2,000
1,500
1,000
500
0
1970
1972
1974
1976
1978
1980
1982
1984
Year
Average Annual Flow
=370,300 ac-ft
1986
1988
1990
1992
1996
1998
2000
Streamflow (1,000 ac-ft)
2,500
2,000
1,500
1,000
500
0
1970
1972
1974
1976
1978
1980
1982
1984
1986
Year
Average Annual Flow
=893,400 ac-ft
1988
1990
1992
1994
1996
1998
2000
LEGEND
# USGS Streamflow Gage
Figure 4-5b
Annual Streamflow Variation
4-16

Bear
6
ALPINE
THAYNE
AFTON
COKEVILLE
EVANSTON
TETON
Snake/Salt
JACKSON
LINCOLN
25
KEMMERER
OPAL
24
26 26
LYMAN
UINTA
MOUNTAIN VIEW
BIG PINEY
LA BARGE
SUBLETTE
GRANGER
PINEDALE
PARK
Wind/Bighorn
DUBOIS
GREEN RIVER
22 22 23
CODY
HOT SPRINGS
Green
SUPERIOR
SWEETWATER
ROCK SPRINGS
POWELL
PAVILLION
18 16
17 19
21
7
FRANNIE
8
BURLINGTON
20
10 10
RIVERTON
FREMONT
HUDSON
Source: Wyoming's 2006 305(b) State Water Quality Assessment Report
Fecal Coliform
BIG HORN
15
12
9
MANDERSON
KIRBY
THERMOPOLIS
SHOSHONI
13
11
WAMSUTTER
29
LEGEND
53 54 68
66
59
67 55
61 52 55 63
SHERIDAN
57 58
62 51
58
CLEARMONT
14
47 48
64 56 60
46
65
40
45
WASHAKIE
BAGGS
TEN SLEEP
BAIROIL
DIXON
RAWLINS
28
27
SINCLAIR
Selenium Sediment/Siltation Chloride
BUFFALO
Powder/Tongue
JOHNSON
42
32
37
30
35 34
36 31
41
43 44
NATRONA
CARBON
SARATOGA
KAYCEE
ENCAMPMENT
HANNA
CASPER
ELK MOUNTAIN
33
MEDICINE BOW
ROLLING HILLS
GLENROCK
ROCK RIVER
CAMPBELL
49
5 4 4
CONVERSE
Platte
ALBANY
WRIGHT
LARAMIE
DOUGLAS
Other (Phosphate, pH, Habitat,
Metals, Oil, Ammonia, and Temp)
3
2
1
CROOK
WESTON
Northeast
GLENDO
PLATTE
39
38
PINE HAVEN
LOST SPRINGS
WHEATLAND
CHUGWATER
CHEYENNE
UPTON
LARAMIE
50
HULETT
SUNDANCE
NIOBRARA
MANVILLE
LUSK
HARTVILLE
GUERNSEY
FORT LARAMIE
NEWCASTLE
LINGLE
TORRINGTON
GOSHEN
YODER
BURNS
VAN TASSELL
LA GRANGE
"
ALBIN
PINE BLUFFS
Map
Number Name Location
1 BELLE FOURCHE RIVER Exceedences measured between Arch Ck and Hulett.
2 BELLE FOURCHE RIVER From Keyhole Reservoir upstream an undetermined distance above Rush Ck.
3 DONKEY CREEK From confluence with Belle Fourche R upstream to an undetermined distance above Antelope Butte Ck.
4 GILLETTE FISHING LAKE Gillette Fishing Lake.
4 GILLETTE FISHING LAKE Gillette Fishing Lake.
5 STONEPILE CREEK From confluence with Donkey Creek upstream an undetermined distance.
6 BEAR RIVER From Woodruff Narrows Reservoir up to Sulphur Creek.
7 MIDDLE FORK POPO AGIE RIVER Undetermined distances upstream and downstream of City of Lander.
8 OCEAN LAKE Ocean Lake.
9 BIGHORN RIVER From Greybull R upstream to Nowood R.
10 COTTONWOOD CREEK From Bighorn River up to Hamilton Dome Oil Field.
10 COTTONWOOD CREEK From Bighorn River up to Hamilton Dome Oil Field.
11 NOWOOD RIVER From confluence with Bighorn R upstream an undetermined distance.
12 GREYBULL RIVER From confluence with Bighorn R upstream to the Sheets Flat bridge.
13 BIGHORN RIVER From Greybull R downstream undetermined distance above Big Horn Lake.
14 GRANITE CREEK From confluence with Shell Ck upstream approximately 4 miles to an undetermined point near Antelope Butte Ski Area.
15 SHELL CREEK From confluence with Bighorn R upstream an undetermined distance.
16 BIG WASH From confluence with Sage Ck upstream to Sidon Canal.
17 BITTER CREEK From Shoshone R up an undetermined distance above Powell.
18 POLECAT CREEK From confluence with Sage Ck upstream an undetermined distance.
19 SAGE CREEK From confluence with Shoshone R upstream an undetermined distance above Big Wash.
20 SHOSHONE RIVER From confluence with Bighorn Lake upstream an undetermined distance.
21 WHISTLE CREEK From confluence with Shoshone R upstream an undetermined distance.
22 BITTER CREEK From Green R up to Killpecker Ck.
22 BITTER CREEK From Green R up to Killpecker Ck.
23 KILLPECKER CREEK Near Rock Springs, tributary to Bitter Ck.
24 BLACKS FK GREEN RIVER From confluence w/ Hams Fk upstream to an undetermined distance above Smiths Fork.
25 HAMS FORK GREEN RIVER Exceedences measured at Diamondville.
26 SMITHS FORK GREEN RIVER From confluence with Blacks Fork past Cottonwood Ck.
26 SMITHS FORK GREEN RIVER From confluence with Blacks Fork an undetermined distance upstream.
27 BATTLE CREEK WEST FORK From Battle Cr to Haggarty Ck.
28 HAGGARTY CREEK From Ferris-Haggarty Mine to W. Fk. Battle Ck.
28 HAGGARTY CREEK From Ferris-Haggarty Mine to W. Fk. Battle Ck.
28 HAGGARTY CREEK From Ferris-Haggarty Mine to W. Fk. Battle Ck.
29 CROOKS CREEK From SW NE S18 T28N R92W undetermined distance downstream.
30 CASPER CREEK In Kendrick Reclamation Project below Casper Canal.
31 GOOSE LAKE In Kendrick Reclamation Project.
32 ILLCO POND S13 T35N R81W.
33 NORTH PLATTE RIVER Exceedences measured at Casper. Impairment extends undetermined distance upstream and downstream.
34 OREGON TRAIL DRAIN In Kendrick Reclamation Project.
35 POISON SPIDER CREEK In and above Kendrick Reclamation Project.
35 POISON SPRING CREEK In Kendrick Reclamation Project below Casper Canal.
36 RASMUS LEE LAKE In Kendrick Reclamation Project.
37 THIRTYTHREE MILE RESERVOIR On South Fork Casper Ck in Kendrick Reclamation Project.
38 ROCK CREEK Above Town of Wheatland.
39 WHEATLAND CREEK Impairment undetermined distance above and below Hwy 320.
40 POWDER RIVER From S Fk Powder R downstream to the confluence with Crazy Woman Creek.
41 POWDER RIVER From Salt Ck downstream to the confluence with Clear Creek.
42 SOUTH FORK POWDER RIVER From confluence with Middle Fork upstream an undetermined distance above Willow Creek
43 WILLOW CREEK From confluence with South Fork Powder R to an undetermined distance upstream.
44 SALT CREEK From Powder R to an undetermined distance upstream.
45 CRAZY WOMAN CREEK From Powder R to an undetermined distance upstream.
46 DALTON DITCH Within and near Town of Story.
47 NORTH PINEY CREEK Confluence with South Piney Creek upstream to an undetermined locationbelow SWNW S12, T53N, R84W.
48 MIDDLE PRONG WILD HORSE CREEK Confluence with Wild Horse Creek upstream an undetermined distance.
49 LITTLE POWDER RIVER Wyoming/Montana state line upstream an undetermined distance above Olmstead Creek
50 CROW CREEK Impairment undetermined distance above and below Cheyenne.
50 CROW CREEK Impairment undetermined distance above and below Cheyenne.
51 BEAVER CREEK From Big Goose Ck to an undetermined distance upstream.
52 BIG GOOSE CREEK From Sheridan to above Beckton.
53 COLUMBUS CREEK From confluence with Tongue River an undetermined distance above Highway 14.
54 FIVE MILE CREEK From confluence with Tongue River an undetermined distance above Ranchester.
55 GOOSE CREEK From confluence of Big and Little Goose Creeks an undetermined distance downstream.
55 GOOSE CREEK Within City of Sheridan.
56 JACKSON CREEK From Little Goose Ck to an undetermined distance upstream.
57 KRUSE CREEK From Little Goose Ck to an undetermined distance upstream.
58 LITTLE GOOSE CREEK From Sheridan upstream to above Big Horn.
58 LITTLE GOOSE CREEK Within City of Sheridan.
59 LITTLE TONGUE RIVER From confluence with Tongue River an undetermined distance above Dayton.
60 McCORMICK CREEK From Little Goose Ck to an undetermined distance upstream.
61 NORTH TONGUE RIVER From confluence of Bull Creek upstream an undetermined distance above Hwy14A.
62 PARK CREEK From Big Goose Ck to an undetermined distance upstream.
63 PRAIRIE DOG CREEK Entire Prairie Dog Creek Drainage.
63 PRAIRIE DOG CREEK From Tongue R to an undetermined distance upstream.
64 RAPID CREEK From Big Goose Ck to an undetermined distance upstream.
65 SACKET CREEK From Little Goose Ck to an undetermined distance upstream.
66 SMITH CREEK From confluence with Tongue River an undetermined distance above Dayton.
67 SOLDIER CREEK From Goose Ck to an undetermined distance upstream.
68 TONGUE RIVER From Goose Ck downstream.
Figure 4-6
2006 303(d) Waters With Water Quality Impairments
4-17

4-18

Groundwater Levels
USGS SW of Carpenter, 410111104223102
10
20
30
40
Water Level
(ft below land surface)
50
60
1973 1975 1977 1979 1981 1983 1985 1987 1989 1991 1993 1995 1997 1999 2001 2003 2005
Year
Note: Gap indicates missing record. Source: USGS 2007 Water Resources Data - Wyoming
Figure 4-8
Example: Groundwater Hydrograph
4-19

Thickness, ft TDS, mg/L
BE
GR
NE
PL
PT
SS
WB
100
200
300
500
1,300
2,500
3,000
>5,000
5
10
15
20
100
250
1,000
>1,000
100
300
500
1,000
3,000
>4,000
Alluvium Qa, Qt sand, gravel, silt, clay ● ● ● ● ● ●
Ogallala Tmu sandstone, siltstone, gravel ●
Teewinot and Salt Lake Tte, Tsl tuff, limestone, claystone ●
Arikaree, North Park, Splitrock Tmo, Tm, Tmu sandstone (tuffaceous) ●●
Bridger, Battle Springs, Fowkes Tb, Tbs, Tf sandstone, conglomerate ●●
Wasatch, Wind River Tw, Twdr, Twk, Twm, Twmo siltstone, sandstone, shale ● ● ●
Fort Union - various members Tfu, Tfl, Tflt, Tftr sandstone, siltstone, coal ● Lance Kl sandstone, siltstone Fox Hills Kfh, Kfl, Kfb sandstone, shale ● ●
Mesaverde and related rocks Kmv, Kav, Kal, Ke, Kr, Kbl sandstone, shale, coal ●●
Cloverly/Dakota KJ, KJs, Kg sandstone, siltstone ● ● ● ●
Nugget J TR n sandstone ● ● ●
Casper, Tensleep, Minnelusa, Hartville
PPc, PPcf, PPh, PPm, PM,
PPM
Madison, Bighorn
Mm, MD, MDO, MDe, MDg,
MO, OЄ, Ob, Pzr
sandstone & limestone, shale ● ● ● ● ● ● ●
limestone, dolomite ● ● ● ● ● ● ●
Flathead Єr sandstone Non-alluvial Deposits Ql, Qg, QTg, Qls, Qs landslide debris, glacial deposits ● ● ● ● ● ●
Arikaree Tmo, Tmu sandstone (tuffaceous) ●
Willwood Twl sandstone, siltstone, mudstone Ft Union Tfu sandstone, claystone, coal ● ●
Evanston Tke conglomerate, sandstone ●●
Lance, Fox Hills Kl, Klm sandstone, shale, siltstone ● ●
Medicine Bow Kmb sandstone, shale Mesaverde Kmv sandstone, shale Frontier Kf, Kft sandstone and shale ● ● ● ● Cloverly (Dakota), Morrison KJ, K , KJs, KJg sandstone, shale ● ●
Sundance, Nugget and related rocks Js, Jsg, J TR , J TR n sandstone, siltstone, gypsum ● ● ●
Twin Creek and Thaynes J TR nd, Jst limestone, shale ● ● ●
Spearfish TR Ps shale, siltstone Phospohoria, Minnekahta Pp, Pmo, MzPz limestone, siltstone, sandstone ● ● ● ● ●
Bighorn, Flathead DO, Єr dolomite, limestone, shale, sandstone ●
Gallatin, Gros Ventre, Flathead Єr limestone, sandstone, shale ●●
Quaternary Deposits Qg, Qls, Qs, Qu sand, gravel, silt, boulders ●
Volcanic rocks
Formations
Qb, Qr, Thr, Ti, Tii, Tcv, Tts,
Twi, Ttl, Tt, Ts, Ttp, Twp,
Taw, Tv
lava flows, mudflows, ash, tuff, breccia ●●
Camp Davis, Colter, Hoback Tcd, Tc, Th conglomerate, mudstone ●
White River Twr, Twru, Twrb, Twrc siltstone, claystone ● ●
Wagon Bed, Crandall Twb, Teml, Tcr, TKu sandstone, siltstone, mudstone ●
Hanna Tha shale, sandstone, coal Ferris TKf sandstone, shale, conglomerate ●
Sohare, Harebell Kso, Ksb, Kha, Kb sandstone, shale, siltstone Aspen, Bear River Ka, Kbr, Kg shale, sandstone, siltstone ●
Sundance Js, Jsg shale ●
TR c, J TR gc, J TR gn, TR cd, TR Pcg,
Chugwater and related rocks
TRPg
siltstone, sandstone, gypsum ●
Woodside and Dinwoody J TR ad, TR cd siltstone, shale ● ● ●
Amsden PPMa, PPM shale Indian Meadows Tim claystone ●
Meetsetse and Lewis Km, Kle, Kml siltstone, claystone, shale ● ● ● ●
shale ● ● ● ● ● ● ●
Cody, Pierre, Steele, Niobrara, Baxter, Carlisle
Kc, Kp, Ks, Kn, Knc, Kcl,
Kgb, Kgbm, Kh, Kba
Thermopolis, Mowry, Aspen
Kmt, KJk, Kmr, Kgb, Kgbm,
Kns, Ka, Kbr
Chugwater, Goose Egg TR c, TR cd, TR Ps, TR Pcg, TR Pg siltstone, sandstone, gypsum ●●
shale ● ● ● ● ● ●
Precambrian rocks granite, gneiss, schist ● ● ● ● ● ● ●
1 Map symbols for the Geologic Map of Wyoming (Love and Christiansen, 1985)
2 BE - Bear; GR - Green; NE - Northeast Wyoming; PL - Platte; PT - Powder/Tongue; SS - Snake/Salt; WB - Wind/Bighorn
Basins of Occurrence 2 Yields, gpm
Standard Map Symbols 1 Dominant Lithology
LEGEND
Major Aquifer - Alluvial Major Aquifer - Sandstone Major Aquifer - Limestone
Unclassified
Minor Aquifer
Marginal Aquifer Major Aquitard
Frannie
Cowley
Deaver
Byron
Dayton Ranchester
Sheridan
Lovell
Powell
Hulett
Cody
Greybull
Clearmont
Burlington
Basin
Buffalo
Pine Haven
Moorcroft
Meeteetse Manderson
Gillette
Upton
Worland
Ten Sleep
"
Sundance
Newcastle
Alpine
Thayne
Afton
Kirby
Dubois
Thermopolis
Jackson
Pavillion
Hudson
Shoshoni
Riverton
Kaycee
Wright
Edgerton
Midwest
Rolling Hills
Pinedale
Mills
Glenrock
Lander
Douglas
Casper
Marbleton
Big Piney
La Barge
Evansville
Guernsey
Lusk
Van Tassell
Bairoil
Cokeville
Wheatland
Lingle
Torrington
Yoder
Hanna
Kemmerer Diamondville
Superior
Medicine Bow
Opal
Rawlins Sinclair
Chugwater La Grange
Granger
Rock Springs
Wamsutter
Elk Mountain
Rock River
Saratoga
Green River
Evanston
Lyman
Laramie
Albin
Mountain View
Riverside
Burns Pine Bluffs
Encampment
Dixon
Cheyenne
Baggs
Glendo
Manville
Lost Springs
Fort Laramie
Hartville
Figure 4-9
Hydrogeology Map
4-20

FRANNIE
RANCHESTER
DEAVER COWLEY
DAYTON
LOVELL
SHERIDAN
BYRON
POWELL
SHERIDAN
HULETT
PARK
CLEARMONT
BIG HORN
CROOK
CODY
CAMPBELL
GREYBULL
BURLINGTON
BASIN
BUFFALO
Powder/Tongue
SUNDANCE
PINE HAVEN
Wind/Bighorn
GILLETTE
MOORCROFT
MANDERSON
UPTON
WORLAND
TEN SLEEP
JOHNSON
TETON
HOT SPRINGS
WASHAKIE
KIRBY
WRIGHT
KAYCEE
Snake/Salt
JACKSON
THERMOPOLIS
DUBOIS
Northeast
WESTON
NEWCASTLE
MIDWEST
ALPINE
PAVILLION
SHOSHONI
RIVERTON
NIOBRARA
CONVERSE
THAYNE
FREMONT
NATRONA
ROLLING HILLS
HUDSON
PINEDALE
GLENROCK
LANDER
MILLS CASPER
MANVILLE
SUBLETTE
LUSK
AFTON
DOUGLAS
LOST SPRINGS
VAN TASSELL
BIG PINEY
GLENDO
LINCOLN
HARTVILLE
LA BARGE
GUERNSEY
BAIROIL
FORT LARAMIE
COKEVILLE
Bear
Green
MEDICINE BOW
HANNA
KEMMERER
OPAL
RAWLINS
SUPERIOR
SINCLAIR
ROCK RIVER
Platte
PLATTE
WHEATLAND
CHUGWATER
LINGLE
TORRINGTON
GOSHEN
YODER
CARBON ELK MOUNTAIN
LA GRANGE
WAMSUTTER
ALBANY
GRANGER
SWEETWATER
ROCK SPRINGS
GREEN RIVER
SARATOGA
ALBIN
LYMAN
UINTA LARAMIE
LARAMIE
EVANSTON
MOUNTAIN VIEW
BURNS PINE BLUFFS
ENCAMPMENT
CHEYENNE
BAGGS
DIXON
LEGEND
Active Well Active Well, > 500 gpm
Source: Wyoming State Engineer's Office GIS files compiled June 2006
"
Figure 4-10
Active Wells
4-21

4-22

FRANNIE
LOVELL
BYRON
POWELL
PARK
Wind/Bighorn
DEAVER COWLEY
RANCHESTER
SHERIDAN
SHERIDAN
HULETT
CLEARMONT
BIG HORN
CAMPBELL
CROOK
CODY
GREYBULL
BURLINGTON
SUNDANCE
BASIN
PINE HAVEN
BUFFALO
GILLETTE
MOORCROFT
MANDERSON
MEETEETSE
UPTON
WORLAND
TEN SLEEP
TETON
HOT SPRINGS
WASHAKIE
KIRBY
Snake/Salt
JACKSON
WESTON
NEWCASTLE
JOHNSON
WRIGHT
KAYCEE
THERMOPOLIS
DUBOIS
Powder/Tongue
Northeast
ALPINE
PAVILLION
SHOSHONI
RIVERTON
NIOBRARA
CONVERSE
THAYNE
FREMONT
NATRONA
ROLLING HILLS
HUDSON
PINEDALE
GLENROCK
LANDER
MILLS CASPER
MANVILLE
SUBLETTE
LUSK
AFTON
DOUGLAS
LOST SPRINGS
VAN TASSELL
BIG PINEY
GLENDO
LINCOLN
HARTVILLE
LA BARGE
GUERNSEY
BAIROIL
FORT LARAMIE
PLATTE
COKEVILLE
WHEATLAND
Bear
KEMMERER
OPAL
Green
GRANGER
SWEETWATER
ROCK SPRINGS
MEDICINE BOW
HANNA
RAWLINS SINCLAIR
ROCK RIVER
CARBON ELK MOUNTAIN
WAMSUTTER
Platte
LINGLE
TORRINGTON
GOSHEN
YODER
CHUGWATER
LA GRANGE
ALBANY
GREEN RIVER
SARATOGA
ALBIN
LYMAN
UINTA LARAMIE
LARAMIE
EVANSTON
MOUNTAIN VIEW
BURNS PINE BLUFFS
ENCAMPMENT
CHEYENNE
BAGGS
DIXON
LEGEND
CBM Well
Source: Wyoming State Engineer''s Office GIS files compiled June 2006.
"
Figure 4-12
Active CBM Wells
4-23

5.0 USE
5.1 INTRODUCTION
This chapter presents an inventory of water use and existing water development projects in
Wyoming. The purpose of this chapter is to provide the necessary understanding of the location, source,
and quantity of water use. This existing water use profile is the basis for the subsequent sections in the
report. State water use was determined for the following water use sectors, which combined define the
total water consumed or lost due to human influence in the state:
! Agricultural use
! Municipal and domestic use
! Industrial use
! Recreational use
! Environmental use
! Evaporation
5.2 AGRICULTURAL WATER USE
5.2.1 Introduction
This section discusses agricultural water use in each of the seven basins in Wyoming.
Agricultural water use, specifically crop consumptive use through irrigation, accounts for the vast
majority of water consumption (depletions) in Wyoming.
5.2.2 Agricultural Water Use Methodology
In general, the steps listed below were followed (directly or indirectly) in the seven basin plans to
estimate the agricultural consumptive use (depletion) of water (CU). More details on certain aspects of
these steps are discussed in subsequent sections.
! Determine irrigated acreage (5.2.3).
! Identify and document information for key diversion structures, including crop types,
irrigation practices, and general operations (5.2.4).
! Determine supply source for irrigated acreage (5.2.5).
! Calculate potential crop consumptive use (evapotranspiration) and irrigation water
requirements, and determine effective precipitation (5.2.6).
! Calculate water supply: limited, or actual, crop consumptive use or depletion (5.2.7).
! Estimate livestock consumptive use (5.2.8).
5-15-

5.0 USE
Several of the above-mentioned terms have been broadly used in other studies. The definitions
used in each of the basin plans are generally consistent; are consistent with Evapotranspiration and
Irrigation Water Requirements (ASCE, 1990); and are stated as follows:
! Evapotranspiration: The total amount of water that would be used for crop growth if there
was an ample water supply; also called potential consumptive use.
! Effective Precipitation: The portion of precipitation that is available to meet the
evapotranspiration requirements of the crop.
! Irrigation Water Requirement: The amount of water exclusive of precipitation that is
required from surface or groundwater diversions to fully meet crop consumptive use.
Calculated as evapotranspiration less effective precipitation. Also called consumptive
irrigation requirement (CIR).
! Supply-Limited Consumptive Use: The amount of water actually used by the crop, limited
by water availability. Also called depletion.
The seven basin plans vary in their terminology regarding crop irrigation requirement,
consumptive irrigation requirement, and irrigation water requirement, although the meanings are the
same. For this report, we use “irrigation water requirement”, which is consistent with ASCE Manual No.
70 (ASCE, 1990).
5.2.3 Irrigated Acreage
The majority of the appropriated water in the state’s seven river
basins has been appropriated for irrigation. Therefore, an estimate of the
amount of water used for irrigation is central in the development of a
comprehensive state water use inventory. The first step in estimating
irrigation water consumption is to estimate irrigated acreage. Figure 5-1
shows irrigated lands by river basin in Wyoming.
Table 5-1 shows that 1,947,100 acres of Wyoming land are
irrigated and provides a comparison to the irrigated acreage by basin
determined in the 1973 Framework Plan. Generally, the current figure includes groundwater, maninduced
subirrigation, idle lands, and man-made riparian acres, as described in the different basin plans.
The total figure does not include Tribal Futures Projects (52,667 acres) in the Wind/Bighorn Basin
awarded to the Wind River Indian Reservation. However, the Tribal Futures Projects lands have an 1868
priority and play an important role in determining potential water use in that basin (see discussion in
Chapter 6).
5-25-

5.0 USE
Table 5-1 Irrigated Acreage
River Basin
Current Irrigated Lands 2
Surface
1973 Total Total
Water Groundwater
acres
Bear 59,000 64,000 --- ---
Green 3 332,000 331,100 330,980 120
Northeast Wyoming 3 161,000 77,600 59,600 18,000
Platte 553,000 613,000 --- ---
Powder/Tongue 3 See Note 1 161,400 161,180 220
Snake/Salt 94,000 99,000 --- ---
Wind/Bighorn 4 539,000 601,000 --- ---
Total 1,738,000 1,961,000 --- ---
1
In the 1973 Framework Plan, Powder/Tongue Basin is included in Northeast Wyoming Basin. Also, the 1973 Wind/Bighorn
Basin included the Little Bighorn subbasin, but the Little Bighorn is in the 2002 Powder/Tongue Basin.
2 Current irrigated acreage listed for primary source of supply. Idle lands identified in the Northeast Wyoming and
Powder/Tongue basins are not included.
3 Only Green, Northeast, and Powder/Tongue River Basin Plans distinguished between surface water and groundwater
irrigated acreage.
4 Current Wind/Bighorn figure is modeled irrigated acreage for full-supply scenario and does not include Popo Agie Basin or
Tribal Futures Projects.
The nearly 2 million total irrigated acres are approximately 225,000 acres more than was
estimated in 1973, a 13 percent increase. The increase came from the Northeast Wyoming, Platte,
Powder/Tongue, and Wind/Bighorn River Basins, which, combined, accounted for approximately
217,000 acres of the total increase.
The large increase in irrigated acreage over the past 30 years may be due to one or more reasons,
including 1) new permitted, surface water irrigated acreage (likely to be a small percentage); 2) an
increase in already permitted, surface water irrigated acreage (some lands with permitted surface water
rights have not been irrigated but still have valid water rights and may be irrigated); 3) a substantial
increase in groundwater irrigated acreage (new lands that were irrigated with groundwater which were
previously not irrigable by surface water sources); and 4) inconsistent accounting of irrigated acreage
between the 1973 Framework Plan and the recent basin plans (a different accounting of recently irrigated,
idle, subirrigated, etc. lands).
5.2.4 Irrigated Crops
Another essential part of estimating the amount of water used for irrigation is the irrigated crop
distribution. Crop evapotranspiration (ET), irrigation water requirements (IWR), and irrigation methods
can vary by crop type. An accurate assessment of crop distribution is important in the modeling of
consumptive uses and in valuing the agricultural sector dependent on those crops.
Various combinations of data sources and methodologies were used to obtain the best estimates
of crop distribution within each basin: interviews with local water users and administrators (such as
extension agency); producer reports (irrigation district data); stereo aerial photography, U.S. Department
of Agriculture (USDA) agencies (Service Center, Natural Resources Conservation Service [NRCS],
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National Agricultural Statistics Service [NASS], and Census of Agriculture); and field verification.
Consistency of data sources or methodology is not essential when estimating irrigated crop types, but it is
important to have the best available data. See individual basin plans for more details.
Table 5-2 shows a summation of the current estimated active crop distribution percentage and
irrigated acreage. Alfalfa, hay, and pasture are the most abundant crops in the state, accounting for
approximately 1,528,000 acres or 79 percent of all the crops in the state. Row crops make up about 12
percent, while small grains account for nearly 10 percent of the active crops grown in the state. Although
they are not accounted for in the individual basin plans, NASS provides statistics on “Field and Misc
Crops” grown in Wyoming. Between 2000 and 2006, there were between 1,400 and 1,700 acres (an
insignificant amount) of these crops grown. NASS does not include names of specific crops, but this
category may include crops such as sorghum, sunflowers, Christmas trees, pumpkins, and other
vegetables.
Table 5-2 1973 Versus Current Active Crop Distribution
River Basin
Active
Irrigated
Lands
Grass/
Pasture 1 Alfalfa Corn
Bear 64,000 59,000 5,000
acres 3
Sugar
Beets
Beans
Small
Grains 2
Green 4 331,100 298,000 31,000 100 2,000
Northeast Wyoming 5 77,600 53,000 21,000 600 3,000
Platte 613,000 368,000 137,000 43,000 21,000 19,000 25,000
Powder/Tongue 5 161,400 49,000 93,000 6,000 13,400
Snake/Salt 5 99,000 46,000 37,000 16,000
Wind/Bighorn 601,000 70,000 261,000 33,000 78,000 34,000 125,000
Current Total 1,947,100 943,000 585,000 82,700 99,000 53,000 184,400
1973 Framework 6 1,622,000 964,000 369,000 59,000 63,000 33,000 125,000
1
Grass/Pasture category includes any kind of grass or hay (wild, native, tame, other; excluding alfalfa), mountain meadow, and pasture.
2
Small Grains category contains winter wheat, spring wheat, barley, and oats.
3
Above crops aggregated for comparisons; all current basin plans did not distinguish based on identical crop types.
4
Green River Basin Plan reported irrigated crop acreage for some of the subbasins; percent distribution for most; corn and grains acreage taken from
subbasins for which they were reported; other subbasins reported no corn or grain; basin distribution was estimated.
5
Only Northeast Wyoming, Powder/Tongue, and Snake/Salt Basin Plans reported irrigated crop acreage; other acreages calculated from crop
distribution percentages from individual basin plans.
6
1973 Framework Plan included potatoes and other categories.
Table 5-2 shows that the Bear River basin grows forage crops exclusively and the Green River
basin grows forage crops nearly exclusively (99.4 percent). Northeast Wyoming, Powder/Tongue, and
Snake/Salt River Basins grow 95, 88, and 84 percent forage crops, respectively, with some corn and/or
small grains.
In the Platte River Basin, 82 percent of all crops are forage crops. The bulk of that is grown
upstream of Guernsey Reservoir (located on the North Platte River), along the Sweetwater River, above
Pathfinder Reservoir, and in the Upper Laramie subbasin. Downstream of Guernsey Reservoir, in the
Lingle and Torrington area, and in the Wheatland area, is where most of the row crops of corn, sugar
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beets, and beans are grown. Row crops make up about 13 percent of the crop distribution in the basin. In
the Wind/Bighorn River Basin, forage crops account for about 55 percent and small grains about 21
percent of the crops grown in the basin. Row crops make up a significant portion (24 percent) of the crop
distribution in this basin, and are found mostly in the Cody/Powell, Worland, Thermopolis, and
Riverton/Lander valleys.
Table 5-2 compares the statewide irrigated crop distribution from the 1973 Framework Plan to
that from the current seven basin plans. All irrigated crop types reported in the current basin plans show
increases in irrigated acreage and percent of crop distribution with the exception of grass/pasture. It
appears that there has been a shift away from grass/pasture to more alfalfa, row crops, and small grains,
which may be due, in large part, to the substantial increase in groundwater irrigation over the last 30
years. However, fluctuations in statewide crop distribution occur annually (even if on a small scale) and
over many years, and from the snapshot data available in the basin plans, one cannot automatically detect
trends in statewide crop distribution. Furthermore, changes in crop distribution, and thus any trends, tend
to occur in the valleys where there are more options for various crops, such as row crops, not in the higher
elevation areas where only forage crops can be grown. Crop distribution changes occur for various
reasons, including 1) water supply, 2) commodity prices and expenditures, and 3) labor costs and/or
intensity. Due to climatic and geographic conditions, and Wyoming’s livestock production, forage crops
will almost certainly continue to be the most extensive crops grown in the state in the future.
5.2.5 Diversions
Surface Water
Diversion records throughout the state of Wyoming are sparse. In none of the basins is every
diversion continuously recorded. In order to quantify irrigation depletions, each stream segment or
tributary where irrigation occurs would have continuous records of diversions and streamflow for a period
of 10 or 20 years (including dry, low streamflow and wet, high streamflow years); local weather stations
to accurately measure precipitation; and lysimeter (consumptive use) data obtained contemporaneously
with the streamflow and diversion records. For obvious economic and practical reasons, such is not the
case in Wyoming.
Estimates are necessarily made from incomplete records and sometimes inconsistent data. It is
not uncommon in various basins to find only a small percentage of diversions with well-maintained
measuring devices and/or prolonged periods of records. For instance, the Green River Basin Plan
reported, “less than ten percent of the irrigation canals in the basin had diversion records of sufficient
duration and detail to be of value in this analysis”. The Northeast Wyoming River Basin Plan stated,
“Unfortunately, there is very little available data on historical diversions in the Northeast Wyoming River
Basins planning area. Diversion records are available only for the Murray Ditch on Redwater Creek and
much of this irrigation is located in South Dakota, outside the limits of this planning study.” The
Northeast Basin Plan used the relationships between theoretical and actual water use based on diversion
records from the neighboring Powder/Tongue River Basin Plan.
On the other hand, the Bear River Basin Plan reported, “The Bear River Basin, because it
encompasses parts of three states and is governed by an interstate river commission, has excellent data
records. Records of streamflow and diversions are well maintained and extensive.” For the Bear River
Basin, complete daily diversion records in Wyoming were obtained for the 36 key ditch systems from the
Compact Engineer-Manager for 1971 through 1999.
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Lack of diversion data is indicative of the relative lack of regulation of diversions. Examples of
diversion issues that required consideration in the individual basin plans include:
! An inadequate percentage of the irrigation canals in the basin had diversion records of
sufficient duration and detail to be of value in the analysis.
! Interviews regarding irrigation operations were very instructive and valuable. However,
based on responses from districts and individual irrigators, a minority of the basin’s irrigated
acres were represented in this effort.
! Diversion records can be misleading. Some canals provide very detailed and extensive
historical diversion records and show virtually uninterrupted flow throughout recent irrigation
seasons. Basing irrigation supply characteristics on the records of these ditches would
significantly overestimate diversions (and hence IWR) in a whole basin because they do not
represent other headgates that routinely run out of water by early July. In addition, although
measuring devices show flow at all times, records may not show when turnouts are closed for
haying resulting in at least part of that water returning to the river. Therefore, subjective
interpretation was required when reviewing the records to estimate when water diverted is
actually applied to crops.
! Diversion records can also show widely varying operation that appears independent of “wet”
and “dry” years. For instance, average diversions through a canal are higher in a generally
“dry” year than in a “wet” year. In other words, one cannot always tell by diversion records
whether a particular year was considered “wet”, “dry”, or “normal.”
! Reservoir releases exist but are difficult to quantify. Many reservoirs permitted for irrigation
are not monitored regularly for content or releases. The effect of many reservoirs, if paper
evidence is sought, is in the diversion records of headgates downstream, where irrigation can
occur longer with the reservoir than without. Of course, this requires that the headgate
records be kept as well.
From the foregoing, assumptions were necessary regarding primarily the number of days
diversions were in use. These assumptions, however, were made with the input of irrigators and State
Engineer’s Office (SEO) personnel for those ditches with which they were familiar. Table 5-3 shows
basinwide, estimated, average, annual, historical diversions for each basin. Based on the acre-foot/acre
calculations, the Wind/Bighorn River Basin enjoys the most ample water supply.
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River Basin
Table 5-3 Estimated Average Annual Irrigation Surface Water Diversions
Wet Normal Dry
Historical Diversions
Overall
Average 1
Surface
Irrigated
Overall
Unit
Average
Theoretical Diversions
Unit
Maximum Maximum
Diversions Diversions
ac-ft acres ac-ft/ac ac-ft ac-ft/ac
Bear 2 295,000 64,000 4.61 303,000 4.74
Green 2,3 1,011,000 330,000 3.06 1,394,000 4.22
Northeast Wyoming 5 153,000 152,000 152,000 152,000 64,000 2.38 258,000 4.03
Platte 4 1,553,000 612,000 2.54 1,860,000 3.04
Powder/Tongue 5 397,000 349,000 388,000 349,000 161,000 2.17 594,000 3.69
Snake/Salt 2 363,000 99,000 3.67 448,000 4.52
Wind/Bighorn 5 3,028,000 3,148,000 2,324,000 3,166,000 600,000 5.28 3,278,000 5.46
Total 6,889,000 1,930,000 3.57 8,135,000 4.21
1
Overall average in the long-term average for the period of record, and is not the average of the Wet, Normal, and Dry columns.
2
The Bear, Green, Platte, and Snake/Salt River Basin Plans did not provide normal, dry, and wet year scenarios for diversions.
3
Green River Basin diversion data were not developed due to lack of data; data here are estimated by dividing the annual
consumptive use (depletion) of irrigation water by the estimated overall irrigation efficiency. Green River Basin irrigation efficiency
(39.7%) was not reported but calculated as the average of the other six basins, which were calculated by dividing the annual
consumptive use by the estimated historical diversions.
4
Platte River Basin diversions and irrigated acres represent total values, as basin plan did not distinguish between surface water
and groundwater.
5
Only Northeast, Powder/Tongue and Wind/Bighorn River Basin Plans calculated theoretical maximum diversions. Other basin
theoretical maximum diversions are estimated by dividing the total irrigation water requirement by the estimated overall irrigation
efficiency.
Groundwater
Only the Bear River Basin Plan attempted to estimate groundwater diversions (pumping). Thus,
groundwater diversions by basin are not reported here. However, Figure 5-2 is provided to show the
nearly 3,000 active irrigation wells in the state.
Theoretical Maximum Diversion Requirement
Theoretical irrigation water requirement (IWR) of crops advises irrigators on the approximate
amount of irrigation water to fully meet crop needs and is, therefore, useful in determining the diversion
demand necessary to meet that requirement. Not all of the water diverted for irrigation goes to meeting
the IWR; in fact, the IWR oftentimes represents only a minority of the total diversion amount. A
significant portion of the diverted flow is lost to seepage from the main conveyance ditch, lateral ditches,
field ditches, headgate leakage, evaporative losses from sprinklers, ditch tailwater waste, field
wastewater, and deep percolation past the crop root zone. The proportion of water ultimately consumed
by the crop compared to the total volume of water diverted from the stream is referred to as the overall
efficiency (some refer to this as the “consumptive use fraction”). Using estimated overall irrigation
efficiency, one can calculate the theoretical maximum diversion requirement from the theoretical IWR.
Irrigation efficiency typically varies throughout the irrigation season but decreases as the amount
of water applied relative to the crop water requirement increases (Cuenca, 1989). For example, overall
efficiency would typically be at a minimum during the early irrigation season when water supply from the
snowmelt runoff is abundant but crop water requirements are minimal. Conversely, overall efficiency
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would typically be at a maximum during the summer months (July and August) when water supply is
limited, soil moisture is depleted, and crop water requirements are at a maximum.
Table 5-3 shows the estimated theoretical maximum diversion requirements by basin. The
theoretical maximum diversion requirement is not the same in wet, normal, and dry hydrologic years and
is based on the wetter or drier climatic conditions in a basin. The ideal conditions for maximum IWR are
a high, or above average, snowfall/snowmelt producing high streamflow conditions coupled with dry, or
below average, precipitation during the growing season. Statewide, average historical diversions are
approximately 85 percent of theoretical maximum diversion requirements.
5.2.6 Theoretical Irrigation Water Requirement
In the semiarid West, an adequate crop is difficult, if not
impossible, to produce by precipitation alone. Application of
irrigation water is required to supplement the effective precipitation
supply. This section summarizes the theoretical irrigation water
requirement of crops as reported in each of the seven basins. The
water intake of a crop (consumptive use) depends on crop stage,
water availability, and climate factors such as temperature,
humidity, solar radiation, and wind speed.
From ET, the irrigation water requirement is estimated by subtracting effective precipitation. As
stated above, the IWR of crops informs irrigators how much irrigation water is needed at the field and is
useful in determining the amount of water needed from surface water or groundwater sources to meet that
IWR. Table 5-4 shows the estimated IWR by basin.
As crops and climate (mainly precipitation) vary across the state, so does the IWR. Alfalfa,
pasture, and grass hay require the most water and thus have the highest IWRs in a given area, while small
grains and beans use much less water and have a smaller IWR. Figure 3-6 shows the average seasonal
IWR for grass across the state and gives the reader a sense of how IWR changes across the state.
5.2.7 Water Supply-Limited Consumptive Use of Crops
The IWR represents an estimate of what crops would use given a full water supply, but crops are
often grown with less than a full supply. Water availability, timing, canal capacity, efficiency, and labor
intensity/costs are some reasons crops receive less than a full supply. Crop yield is often a good indicator
of whether a crop is well-watered or not. Table 5-5 shows the current total water supply-limited
consumptive use (the amount of water actually consumed by crops) by basin and provides a comparison
to the consumptive use estimated in the 1973 Framework Plan. Comparison to Table 5-4 shows that,
statewide, CU is approximately 84 percent of IWR.
Current total irrigation water consumption is approximately 2.5 million acre-feet, up nearly 0.2
million acre-feet from that in 1973, but one cannot automatically assume an upward trend has developed
in the data from these two time periods. Water consumption fluctuates annually with water availability,
irrigated acreage, crop types, climate, etc. It comes as no surprise that the largest consumptive use of
water in the state is irrigated crop land, and it will continue to be in the foreseeable future.
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Table 5-4 Estimated Average Annual Irrigation Water Requirement
River Basin
Total IWR
Active
Total IWR
Unit IWR
Irrigated
Lands Unit IWR Wet Normal Dry Wet Normal Dry
ac-ft acres ac-ft/ac ac-ft ac-ft/ac
Bear 1 97,000 64,000 1.52
Green 553,000 331,000 1.67 465,000 553,000 576,000 1.41 1.67 1.74
Northeast 103,000 77,000 1.33 95,000 103,000 126,000 1.23 1.34 1.64
Platte 2 658,000 612,000 1.08
Powder/Tongue 238,000 161,000 1.47 217,000 238,000 289,000 1.35 1.48 1.80
Snake/Salt 126,000 99,000 1.27 122,000 126,000 132,000 1.23 1.27 1.33
Wind/Bighorn 1 1,165,000 600,000 1.94
Total 2,940,000 1,944,000 1.47 3
1
Bear and Wind/Bighorn River Basin Plans did not calculate normal, dry, and wet year scenarios but overall averages.
2
Platte methodology does not afford calculation of irrigation water requirement; values estimated by applying average CU:IWR ratio from other basins.
3 Average unit IWR.
Table 5-5 Estimated Average Annual Irrigation Water Supply-Limited Consumptive Use (Depletions)
River Basin
1973 Total
CU
Current
Total CU
Active
Total CU
Irrigated
Lands Unit CU Wet Normal Dry
ac-ft ac-ft acres ac-ft/ac ac-ft
Bear 2 65,000 94,000 64,000 1.47
Green 243,000 401,000 331,000 1.21 432,000 401,000 375,000
Northeast 160,000 86,000 77,000 1.12 88,000 86,000 76,000
Platte 2 686,000 550,000 612,000 0.90 527,000 566,000 515,000
Powder/Tongue See Note 1 184,000 161,000 1.14 194,000 184,000 178,000
Snake/Salt 84,000 102,000 99,000 1.03 105,000 102,000 94,000
Wind/Bighorn 2,3 1,041,000 1,039,000 600,000 1.73
Total 2,279,000 2,456,000 1,944,000 1.23 4
1 In 1973 Framework Plan, Powder/Tongue Basin is included in Northeast Wyoming Basin. Also, the 1973 Wind/Bighorn Basin included the Little Bighorn
subbasin, but the Little Bighorn is in the 2002 Powder/Tongue Basin.
2 Bear, Platte, and Wind/Bighorn values are overall averages, Bear and Wind/Bighorn Basin Plans did not provide normal, dry, and wet year scenarios for
consumptive use estimates. Current total CU for other basins taken from "normal" year averages.
3 Wind/Bighorn River Basin Plan provided full-supply consumptive irrigation requirement but not supply-limited consumptive use. Table value was estimated by
multiplying historical diversions by overall efficiency and does not include Tribal Futures projects or Popo Agie basin.
4 Average unit CU.
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5.2.8 Livestock Consumptive Use
Livestock consumption estimates are based on ten gallons of water per cow per day and four
gallons of water per sheep per day. The pie chart below shows the estimated average annual livestock
water consumption by basin.
5.3 MUNICIPAL AND DOMESTIC WATER USE
Livestock Consumptive Use (ac-ft)
Wind/Bighorn
3,100
Bear
500
Green
3,200
Snake/Salt
500
Powder/Tongue
2,700
Northeast Wyoming
2,900
Platte
6,300
5.3.1 Introduction
Municipal water uses are those uses satisfied by a public water supply system. Municipal water
use is a relatively small but important part of Wyoming’s water use. Figure 5-3 shows the municipalities
in Wyoming by river basin planning area and by primary source of supply. Municipal needs are served
by surface water, groundwater, and combinations thereof.
Primarily, information was obtained from the various municipalities through direct
communication or from various years of the WWDC’s “Water System Survey Report”. Other sources
included the WDEQ and various water supply reports for the areas. The detailed information compiled
for each entity in each of the river basin planning areas is presented in the Municipal Use Technical
Memorandum for that river basin planning area.
The river basin plans compared the existing use and the demand imposed on the municipal
system to the capacity of that system. Most of the municipal systems in Wyoming have adequate capacity
to meet existing needs. There are, however, a number of entities with system capacities close to or less
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than existing demands. Additional information on demand versus system capacity is contained in each of
the river basin planning area reports.
Domestic water uses are those uses which are satisfied by individual wells and small water
systems. The principal users of nonmunicipal domestic water supplies are rural homes, subdivisions,
small trailer courts, commercial establishments, parks, campgrounds, rural schools, domestic uses at coal
mines, and other small water uses that are not supplied from a central public water system. These uses
are almost exclusively supplied from groundwater. A notable exception is limited irrigation of lawns and
gardens from available surface water sources.
5.3.2 Current Water Use
Table 5-6 shows the current municipal and domestic water use for the state by individual river
basins in gallons of use per day. The water use is split between surface water and groundwater. Large
portions of the Platte River Basin population were reported as being served by conjunctive use systems
(use of both surface water and groundwater). Platte River cities with conjunctive use systems include Bar
Nunn, Casper, Cheyenne, Douglas, Laramie, and Rawlins. Table 5-7 presents the annual municipal and
domestic use for each of the river basin planning areas. Figures in this table are shown in acre-feet used
per year. In the Platte River Basin Plan, conjunctive use was estimated and reported. Figure 5-4 shows
municipal wells while Figure 5-5 shows domestic wells in the state.
Table 5-6 Municipal and Domestic Use
Surface Water
Groundwater
River Basin Demand Factor 1 Municipal Domestic Municipal Domestic
gpcpd
gpd
Bear River 2 198 2,056,700 897,000
Green River 3 133 18,682,000 ! 0 646,000 2,598,000
Northeast Wyoming 204 ! 0 ! 0 6,957,000 2,540,000
Platte River 4 197 5,981,000 15,891,000
Powder/Tongue River 270 6,446,000 ! 0 91,000 2,135,000
Snake/Salt River 223 ! 0 ! 0 5,875,140 2,241,000
Wind/Bighorn River 207 8,300,000 1,157,000 3,904,000 5,314,000
1 Demand factors are based on average use in the basin, which are reported as gallons per capita per day (gpcpd). Use is calculated in gallons per
day (gpd).
2
Combined the data for municipal and domestic uses. Number is from percentage of total water use.
3
Surface water data are"depletions" instead of "uses" like the other basins. Also includes 12.9 mgd for City of Cheyenne, which may or may not be
the same as 13 mgd in the Platte Basin total.
4
Includes 13 mgd for City of Cheyenne, which may be duplicated in Green River Basin. Also the only basin plan to report conjunctive uses.
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Table 5-7 Municipal and Domestic Water Depletions
River Basin
Depletions
Surface Water Groundwater Total
ac-ft per year
Bear River 2,300 1,000 3,300
Green River 1 21,800 2,800 24,600
Northeast Wyoming 0 10,100 10,100
Platte River 2 6,700 17,800 24,500
Powder/Tongue
River 7,200 2,500 9,700
Snake/Salt River 0 9,100 9,100
Wind/Bighorn River 10,600 10,300 20,900
Total 48,600 53,600 102,200
1 Municipal depletions in the Green River Basin include 14,400 ac-ft that is diverted into the Platte River Basin for Cheyenne.
2 Platte River Basin municipal use had large amounts of conjunctive use that were not separated into surface water and groundwater. The
conjunctive use was split into surface water and groundwater based on information found in the tech memos.
To estimate current or present use, water demand factors were determined for each river basin
planning area. These demand factors are expressed in gallons of use per capita per day. Table 5-6 shows
the average per capita daily use for each of the river basin planning areas. Individual systems will very
likely exhibit different per capita use; however, the demand factors do indicate per capita use for the
municipal sector across the river basin planning area.
As much of rural domestic water use is not measured, domestic water use factors were estimated
based on the judgment of the individual river basin planning team. For additional information and
detailed discussion, the reader should consult the specific river basin plan and its associated technical
memorandum.
5.4 INDUSTRIAL WATER USE
5.4.1 Introduction
An important water-using sector in Wyoming is the industrial sector. This sector includes electric
power generation, coal mining, conventional oil and gas production, uranium mining, trona mining and
soda ash production, bentonite mining, gypsum mining, and coalbed methane (CBM) production.
Information was obtained during the individual river basin studies through direct communication
with the various industries, the Coalbed Methane Coordination Coalition (CBMCC), Wyoming Oil & Gas
Conservation Commission (OGCC), U.S. Bureau of Land Management (BLM), and SEO. Across the
State some industries did not have records of their water use. Therefore, some estimates had to be
gleaned from anecdotal information. These were often “rule of thumb” numbers used by industry. In
other cases, SEO industrial water right permits were used to estimate water use. For example,
groundwater use in the Wind/Bighorn River Basin was estimated to be 76,533 acre-feet. This number
may be inflated as water rights and permitted amounts were used rather than actual use. This approach
would not account for inactive or shut-in wells that are no longer in use. The methods employed in the
seven river basins are described in more detail in the technical memoranda for the various study areas.
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The amount of industrial water use varies from almost none in some river basin planning areas
such as in the Snake/Salt River Basin to fairly large amounts of water being used such as in the Platte
River Basin. Current use by the industrial sector is described in this section.
5.4.2 Current Water Use
Coal-fired electric power generation plants are currently located in three of the seven river basin
planning areas: the Northeast Wyoming River Basin , Green River Basin, and Platte River Basin.
Four coal-fired electric power plants are now operating in Northeast Wyoming. Three of the
plants, Neal Simpson #1, Neal Simpson #2, and Wyodak #1, are near the Wyodak Mine seven miles east
of Gillette. All three of these plants use air rather than water for cooling steam produced during electric
power generation. As a result, their water consumption is significantly lower than the more conventional
water-cooled electric power plants. The only water-cooled electric generating facility in Northeast
Wyoming is the Osage Station, located near Osage in Weston County. Total annual consumptive water
use for power production at these plants is approximately 1,200 acre-feet.
Two coal-fired electric power plants are located in the Green River Basin: the Jim Bridger Power
Plant near Point of Rocks in Sweetwater County and the Naughton Power Plant south of Kemmerer in
Lincoln County. The Naughton Plant has a production capacity of 710 megawatts (MW) and
consumptively uses approximately 13,500 acre-feet of water annually from the Hams Fork River. The Jim
Bridger Plant has a production capacity of 2,000 MW and consumptively uses approximately 34,300 acrefeet
of water annually from the Green River. Much of the power from the Naughton Plant is exported via
transmission lines to Utah, while much of the power from the Jim Bridger Plant is exported to PacifiCorp
customers in the Pacific Northwest.
In the Platte River Basin, the Laramie River Station in Platte County is operated by Basin Electric
Power Cooperative and has a generating capacity of 1,670 MW. This plant uses about 23,250 acre-feet of
water annually. The Dave Johnston Power Plant located in Converse County is owned and operated by
Rocky Mountain Power and has a generating capacity of 817 MW. This plant uses about 8,600 acre-feet
of water annually.
For surface water, the Green River Basin leads in industrial water use with an estimated 66,280
acre-feet. The Northeast Wyoming River Basin, Powder/Tongue River Basin, and Platte River Basin also
use fairly large quantities of groundwater for industrial purposes. Table 5-8 shows the estimated present
use of surface water and groundwater for industrial purposes. Some of the river basin plans did not
estimate use for the minor sectors such as aggregate mining, concrete production, manufacturing, road
and bridge construction, and miscellaneous industrial use. Many of these minor uses exist in all of the
river basin planning areas; however, the Platte River Basin plan had the most all inclusive list of
industrial use. Due to the differences in methods used in the seven river basin planning area studies, the
totals shown in Table 5-8 may not accurately reflect industrial use.
Figure 5-6 shows the locations of industrial and miscellaneous wells. Miscellaneous use is a
beneficial use category used by the SEO to categorize small yield wells where there is no defined major
use. Total current industrial surface water use for Wyoming is estimated to be 124,490 acre-feet per year.
Total current industrial groundwater use is estimated to be 246,130 acre-feet per year.
More extensive discussion of the individual river basin industrial water uses can be found in the
individual river basin plans and associated technical memoranda.
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Table 5-8 Annual Industrial Water Use
River Basin
Coal-Fired
Electric Power
Conventional
Oil and Gas
Mining and
Mine Trona Mining/
Reclamation 1 Soda Ash
Methane 4 Manufacturing Misc 2 Concrete 2 Construction 2 TOTAL
Aggregate, Road and
Coal Bed
Cement, Bridge
Surface Water Use (ac-ft)
Bear 0 300 0 0 0 300
Green 47,800 17,900 560 66,260
Northeast 0 0
Platte 31,900 2,700 450 0 4,600 580 2,000 42,230
Powder/Tongue 0 0
Snake/Salt 0 0 0 0
Wind/Bighorn 0 0 0 15,700 15,700
Total Surface Water 79,700 3,000 450 17,900 0 16,260 4,600 580 2,000 124,490
Groundwater Use (ac-ft)
Bear 0 90 0 0 90
Green 0 1,600 0 0 1,600
Northeast 1,200 10,400 2,700 0 35,600 49,900
Platte 0 17,600 17,500 0 0 9,300 11,200 0 55,600
Powder/Tongue 0 38,000 0 24,300 62,300
Snake/Salt 0 0 0 0 0 140 140
Wind/Bighorn 3 0 73,800 2,700 0 0 0 76,500
Total Groundwater 1,200 141,490 22,900 0 59,900 140 9,300 11,200 246,130
1 Green River Basin coal mining water use is included in power generation.
2 Estimates for these sectors were made only for the Platte River Basin.
3 Wind/Bighorn Basin conventional oil and gas use is water righted use.
Note: Blank spaces for water use in a particular basin indicate no estimate was made, not that there was no use.5-24
5-
5-14

5.0 USE
5.5 RECREATIONAL WATER USE
5.5.1 Introduction
Recreational uses of water are important and generally nonconsumptive. Uses include boating,
fishing, swimming, and waterfowl hunting among others. While consumption of water is usually not
involved, the existence of a sufficient water supply for a quality experience is important. The quality and
quantity of good recreational opportunities are highly dependent on water quality and quantity.
Recreation, including tourism, is one of Wyoming’s major industries. Hunters and anglers alone spent
$700,588,360 in the state in the year 2000.
Data for this section of the report were obtained for the seven basin plans from the regulatory
agencies assigned the task of managing recreation in basin waterways. Those agencies include the
Wyoming Game and Fish Department (WGFD), Wyoming Department of State Parks and Cultural
Resources, USFWS, BLM, and USBR.
5.5.2 Current Water Use
Tourism and recreational use consist of two sectors,
resident use and nonresident (tourism) use. Due to a lack of
water-based recreational opportunities, some areas of Wyoming
are not tourist destinations. The northwest portion of the state,
on the other hand, is a popular recreation destination and
experiences large visitation. This area includes the Snake/Salt
River Basin, part of the Green River Basin, and part of the
Wind/Bighorn River Basin.
The following sections describe the major types of
recreation in the State that require water:
! Fishing
! Boating
! Waterfowl hunting
! Skiing and winter sports
! Golfing
Fishing
Fishing is a major water-based recreational activity pursued in the state. It is the most popular
water-based recreational activity for residents in many areas of the state. As with boating, fishing is a
nonconsumptive use of water, and in most cases is dependent on water devoted to other uses such as
irrigation or municipal. A notable exception to this dependency is the instream flow water right program
administered by the State of Wyoming. Instream flows are discussed later in this chapter.
The State of Wyoming classifies trout streams under the five designations listed below:
! Class 1 – Premium trout waters – fisheries of national importance
! Class 2 – Very good trout waters – fisheries of statewide importance
! Class 3 – Important trout waters – fisheries of regional importance
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5.0 USE
! Class 4 – Low production trout waters – fisheries frequently of local importance, but
generally incapable of sustaining substantial fishing pressure
! Class 5 – Very low production waters – often incapable of sustaining a trout fishery
The WGFD estimates the number of annual activity days of angling and waterfowl hunting in the
state. Still water fishing on lakes and reservoirs accounts for the largest percentage of fishing activity
days annually. Most of this fishing activity occurs at lowland reservoirs. In some parts of the state, still
water fishing on alpine lakes and reservoirs contributes to the total still water fishing.
Stream fishing in Wyoming accounts for a large number of activity days annually in some river
basin planning areas, such as in the Green River Basin where it was estimated 300,000 angler activity
days annually are experienced. Stream fishing opportunities are limited in other river basin planning
areas. Northeast Wyoming is a good example of a river basin with limited stream fishing opportunities,
although there are some good streams, such as Sand Creek, which arise in the Black Hills.
Table 5-9 illustrates the angler days for the state by basin. The days are split between stream and
still water fishing.
Table 5-9 Angler Days
Angler Days
River Basin Stream Still Water
Bear River 9,400 7,400
Green River 256,300 485,600
Northeast Wyoming 13,400 38,300
Platte River 1 385,400
Powder/Tongue River 140,200 131,700
Snake/Salt River 1 116,000
Wind/Bighorn River 2 51,300
Total 1,635,000
1
No data were presented to separate stream angler days from still water angler days.
2
The data are the number of fishing licenses sold in the five counties of the basin.
Boating
Many of the streams and lakes in Wyoming support boating activities, including whitewater,
scenic, fishing, and water-skiing. Power boating, rafting, canoeing, and sailing are all popular waterbased
activities among Wyoming residents. Boating is a nonconsumptive use because it depends on
waters being maintained for other purposes.
Little quantitative data exist on the numbers of watercraft using the streams and lakes and
whether numbers approach or exceed the carrying capacity of the water body used. The USBR’s default
figure of one boat per 10 surface acres of water is used to estimate capacities elsewhere, but until use
numbers are generated in the state to support this estimate, that guideline cannot be used.
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A quality boating experience requires a water level (in lakes) or flow rate (in rivers) sufficient to
support the reason for boating, whether it be fishing, water-skiing, or some other sport. In this context,
future water development projects should be evaluated for their effect on such levels.
Waterfowl Hunting
Waterfowl hunting is another popular activity among Wyoming residents. The harvest of
migratory waterfowl is a recreational pursuit affected by the presence or absence of water. Wetlands and
open water are needed for breeding, nesting, rearing, feeding, and isolation from land-based predators. In
the state of Wyoming, waterfowl hunting is pursued where sufficient local or migratory populations are
available.
Harvest objectives have not been used since 1993. In effect, the desired harvest is a prospective
number using past hunter success, population effects, and regulations in concert with current-year
populations.
With current duck populations and hunting pressure, it appears there is a sufficient resource to
provide a quality duck hunting experience now and in the near future, with the existing water resources of
the State. Goose hunting seasons and bag limits are set under guidelines from the USFWS, although
states have more flexibility in setting bag and possession limits. Like duck populations, goose
populations are strong and increasing. With approval from the USFWS, states can set special seasons to
allow depredation harvest from growing local flocks. With current goose populations, it appears there is a
sufficient resource to provide a quality goose hunting experience now and in the near future, with the
existing water resources of the state.
Skiing and Winter Sports
Downhill skiing is another recreational water consumer. The major consumption is through
evaporation during the snowmaking process. It has been estimated that snowmaking is about 20 percent
consumptive. Snowmaking is practiced at many of the ski areas, particularly the larger ones. While
downhill skiing is a consumptive user, the water use is a minor one.
The major ski areas in the state are located in the Snake/Salt River Basin. They include Snow
King Resort, Grand Targhee Resort, and Jackson Hole Mountain Resort. Ski areas of local and regional
importance exist in all of the river basin planning areas except Northeast Wyoming. Most of the ski areas
have incorporated snowmaking facilities into their resorts. Figure 5-7 shows the ski areas of Wyoming.
Other winter sports in the state include cross-country skiing, snowshoeing, and snowmobiling.
These activities are prevalent across Wyoming.
Golfing
Golfing and golf courses are scattered across all the river
basin planning areas. In the Platte River Basin, there are 19 golf
courses with nearly 300 holes covering about 2,000 acres. There are
five courses in the Snake/Salt River Basin with three new ones
planned for Teton County and one new course planned for Lincoln
County. These are just a portion of the total number of courses in
the state.
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5.0 USE
Figure 5-7 shows the location of many of the golf courses in the state, and the website
http://www.thegolfcourses.net indicates there are 34 municipalities with at least one course listed plus the
course at Warren Air Force Base.
The major water use is for irrigation of the greens and fairways. This use is often included in
municipal use similar to park and cemetery use. While golfing is a consumptive user, the water use is a
minor one.
Wyoming State Parks and Historical Sites
Wyoming is home to several state parks and historic sites which
offer many recreational water activities for visitors. Figure 5-8 shows
the location of the various parks and historic sites administered by the
State Parks Division.
The 1997 Wyoming State Parks and Historic Sites Visitor
Survey, compiled by the University of Wyoming, Survey Research
Center, provides additional information. About 86 percent of all
visitation (to all parks and historic sites) occurs in the months of June,
July, and August, with attendance in each of those months almost equal. Slightly over half the visitors are
first-time visitors. Approximately one in four visitors is traveling with a boat or canoe, indicating some
water-based recreation is intended, either at that location or elsewhere on that particular trip.
Approximately 58 percent of the visitors are from out of state.
Wind River Indian Reservation
The Wind River Indian Reservation (WRIR) is home of the Eastern Shoshone and Northern
Arapaho Tribes. Natural resources on the WRIR are in general jointly owned by the two Tribes.
(Additional information on the tribal lands is provided in Chapter 3, Section 3.3.2.)
Within the WRIR are more than 200 lakes and over 1,000 miles of streams. Fishing on the WRIR
requires a tribal license. The Tribes reported selling 2,472 permits in 1998 and 3,577 in 1999. About 60
percent of these sales were to nonresidents (University of Wyoming, Cooperative Extension Service,
1999). There is significant potential for further development of recreational opportunities, including
water-based activities, in the WRIR.
National Parks and Monuments
There are two national parks in Wyoming, Grand Teton National Park and Yellowstone National
Park. Grand Teton National Park is located entirely within the Snake/Salt River Basin. Yellowstone
National Park is split between the Snake/Salt River Basin and the Wind/Bighorn River Basin. Both of
these parks have extensive recreational water activities.
Visitors to Yellowstone National Park provide a significant portion of the tourism in northwest
Wyoming. From 1996 through 2005, recreational visitors to Yellowstone National Park averaged nearly
three million people per year (Table 5-10). The East Entrance, west of Cody, averaged fewer than
400,000 per year during the 1992-1998 period (Yellowstone National Park, Visitation Statistics). The
South Entrance, reached through Fremont and Teton Counties (as well as from the west and south),
averaged more than 800,000 per year during the same period. These numbers suggest that fairly large
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numbers of people bound for Yellowstone Park pass through the Wind/Bighorn River Basin and
Snake/Salt River Basin each year.
There are also two national monuments in the State: Devil’s Tower and Fossil Butte National
Monument. Devil’s Tower was the first national monument to be declared and is located in the Northeast
Wyoming River Basin. Fossil Butte has some of the world’s best preserved fossils, including fish, plants,
insects, reptiles, birds and mammals. Fossil Butte is located in the Bear River Basin.
Figure 5-9 shows the location of the national parks and monuments.
Table 5 -10 Visitation to National Parks and National Monuments
Park or Monument Visitation 2005 Average Visitation 1996 to 2005
Yellowstone NP 2,836,000 2,945,000
Grand Teton NP 2,463,000 2,575,000
Devils Tower NM 370,000 394,000
Fossil Butte NM 18,000 21,000
Total 5,687,000 5,935,000
Source: National Park Service Annual Visitation Reports - 2006
National Forests
Wyoming is also home to eight national forests and one national grassland. The national forests
are: Ashley, Bighorn, Black Hills, Bridger-Teton, Medicine Bow, Shoshone, Targhee, and Wasatch. The
national grassland is Thunder Basin. Figure 5-9 shows the national forests and national grassland in
Wyoming.
Summary of Recreational Use
In general, the recreational uses of water around the state are nonconsumptive. These uses do,
however, require an adequate supply of water. Golf course irrigation is an exception to the
nonconsumptive claim. However, this use was not accounted for in most of the river basin plans.
5.6 ENVIRONMENTAL WATER USE
5.6.1 Introduction
Previous studies conducted by the WWDC, SEO, and Game and Fish Department have estimated
the amount of water designated for or consumed by various environmental uses. These include, but are
not necessarily limited to, instream flow water rights permitted by the Wyoming State Engineer,
minimum reservoir pools, instream flow bypasses designated to enhance fisheries and wildlife habitat,
wetlands, direct wildlife consumption, evaporation from conservation pools, and maintenance of riparian
areas.
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5.0 USE
5.6.2 Current Water Use
Environmental water uses are generally considered nonconsumptive and therefore do not have a
specific use assigned to them. The following environmental factors need to be considered when
discussing water use.
Instream Flows
In 1986, the State of Wyoming enacted legislation defining “instream flow” as a beneficial use of
water and stipulated how instream flow water rights would be filed, evaluated, granted or denied, and
ultimately regulated (Wyoming Statutes at Section 41-3-1001 to 1014). The law allows for instream flow
water rights to be filed and granted on unappropriated water originating as natural flow or from storage in
existing or new reservoirs. For natural flow sources, the flow amount is defined as the minimum needed
to “maintain or improve existing fisheries”. The language relating to stored water is slightly different,
defining the minimum needed to “establish or maintain new or existing fisheries”. Instream flow is
generally considered a nonconsumptive beneficial use.
The WGFD first selects the stream segment on which to file for a right. This is done using
biological reports, knowledge of the fisheries, and stream flow models, along with determination of how
much flow will be required. The WWDC then applies for the appropriation. The WWDC must also
conduct a hydrologic study to determine whether the instream flow can be provided from the
unappropriated natural flow of the stream or whether storage water from an existing or new reservoir will
be needed for part or all of the instream use. The WWDC study is then supplied to the State Engineer for
his consideration.
After receiving reports from the WGFD and WWDC, the State Engineer may conduct his own
evaluation of the proposed appropriations for instream use. Before granting or denying a permit for
instream flow in the specified stream segment, the State Engineer must conduct a public hearing and
consider all available reports and information. In the past, public involvement has ranged from very little
to quite significant. Following the public input period, the State Engineer decides whether or not to
approve, approve with modifications, or reject the application. If granted, an instream flow permit can
contain a condition for review of continuation of the permit at a future time. Also, the WWDC is named
as holder of the permit.
The instream flow appropriation goes into effect the date the State Engineer approves the permit.
The water right cannot be adjudicated by the Board of Control for three years thereafter. An instream
water right has a priority date as of the date the application was received and recorded by the SEO, and all
senior priority water rights must be recognized in administration of the stream.
Only municipalities can condemn an instream flow right. However, within one mile of the state
border, the water for an instream flow right is still open to appropriation. This allows for additional
utilization of water prior to the flow leaving the state. Existing water rights cannot be condemned for
instream flow; however, they can be gifted to the State for instream use. This has not yet happened.
Regulation of water rights on a stream must be called for by the WGFD with the request proceeding
through the WWDC. Instream flow rights do not ensure ingress and egress rights to the stream for public
use; however, the WGFD has tried to ensure that the segments with instream rights have public access as
well. Also, these rights cannot be issued if they will limit Wyoming’s use of water with respect to
interstate compacts.
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The first filings in Wyoming for instream flow rights were for protection of various species of
cutthroat trout. There are currently 100 instream flow applications filed with the State, with 66 having
been permitted as of December 2006. Instream flow filings for rivers and streams in the state are shown
in Figure 5-10.
Reservoir Minimum Pools
Several reservoirs in the state have storage permitted for a variety of environmental uses. These
uses, as they appear on the water rights, include fish or fish and wildlife. Recreational uses defined on
permits can be considered environmental to the extent that water in storage for recreational purposes, and
not released for other consumptive or nonconsumptive uses, can be beneficial, in an environmental sense,
for fish habitat and wildlife consumption. Reservoirs with permitted capacity for stock water similarly
serve a dual environmental function.
"Conservation storage" describes all of the storage capacity allocated for beneficial purposes and
is usually divided into active and inactive areas or pools. "Active storage" or “Active conservation pool”
refers to the reservoir space that can actually be used to store water for beneficial purposes. Each
reservoir has an allocation for an active conservation pool, which holds reservoir inflow for such uses as
irrigation, power, municipal and industrial, fish and wildlife, navigation, recreation, and water quality.
Inactive storage refers to water beneath the lowest outlet structures where water cannot be released by
gravity and to areas expected to fill up with sediments. This storage is often needed to increase the
efficiency of hydroelectric power production.
Direct Wildlife Consumption
There are no current estimates of consumptive water use by wildlife for six of the river basin
planning areas. An estimate developed for the Green River Basin puts consumptive use by big game and
wild horses at about 500 acre-feet of water annually. It was assumed in the Powder/Tongue River Basin
and in the Northeast Wyoming River Basin studies that a similar figure would be roughly correct for
those basins. If all river basin planning areas are assumed to be similar to the Green River Basin, use
would be about 3,500 acre-feet annually. This level of consumptive use is relatively small and is not
expected to change significantly over the planning horizon.
Threatened and Endangered Species
The presence of threatened or endangered species of plants and animals, or of species that might
be considered for such listing, can make water management and development more complex. A number
of species in Wyoming are so listed by the U.S. Fish and Wildlife Service. Section 2(c)(2) of the
Endangered Species Act requires state and local agencies to cooperate with federal agencies in issues
involving such species. Particularly in cases in which federal land is involved, such cooperation means
conducting wildlife and plant studies of the targeted area. Some examples of animal species include the
grizzly bear, whooping crane, Kendall Warm Springs dace, bald eagle, black-footed ferret, lynx, Preble’s
meadow mouse, pike minnow (squawfish), razorback sucker, Wyoming toad, and gray wolf. Some listed
plant species are Colorado butterfly plant, blowout penstemon, Ute ladies’ tress, and desert yellowhead.
There are also other species that have been proposed for addition to the threatened list, and a long list of
candidates (258 species) for endangered or threatened status.
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In regard to threatened and endangered species, however, the USFWS states that “while it is
prudent to take candidate taxa into account during environmental planning, neither the substantive nor
procedural provisions of the Act apply to a taxon that is designated as a candidate.” Nonetheless, as a
practical matter, the presence or possible presence of threatened, endangered, proposed, or candidate
species in locales that could be affected by water projects must be considered by developers. Wildlife and
plant (and cultural) studies are routinely done early on in most projects, particularly if public lands are
involved.
Wetlands
The National Wetlands Inventory (NWI) of the USFWS
produces information on the characteristics, extent, and status of
the nation’s wetlands and deepwater habitats. Wetlands are lands
transitional between terrestrial and aquatic systems where the
water table is usually at or near the surface or the land is covered
by shallow water. For purposes of this classification, wetlands
must have one or more of the following three attributes:
! At least periodically, the land supports predominantly
hydrophytes.
! The substrate is predominantly undrained hydric soil.
! The substrate is nonsoil and is saturated with water or covered by shallow water at some time
during the growing season of each year.
The wetland classification system is hierarchical, with wetlands and deepwater habitats divided
among five major systems at the broadest level. The five systems are as follows.
! Marine
o Open ocean and associated coastline
! Estuarine
o Salt marshes and brackish tidal water
! Riverine
o Rivers, creeks, and streams
! Lacustrine
o Lakes and deep ponds
! Palustrine
o Shallow ponds, marshes, swamps, sloughs
Systems are further subdivided into subsystems which reflect hydrologic conditions. Below the
subsystem is the class which describes the appearance of the wetland in terms of vegetation or substrate.
Each class is further subdivided into subclasses; vegetated subclasses are described in terms of life form
and substrate subclasses in terms of composition. The classification system also includes modifiers to
describe hydrology (water regime), soils, water chemistry (pH, salinity), and special modifiers relating to
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human activities (e.g., impounded, partly drained). The three major wetland systems mapped within the
Snake/Salt River Basin are Riverine, Lacustrine, and Palustrine.
Wetlands in the state provide food, shelter, and breeding habitat for waterfowl and other wildlife.
Wetlands may also improve water quality by contributing to the removal of nutrients, sediment, and other
impurities in water, in turn protecting rivers and lakes. Also, wetlands can help control erosion and
flooding during high water events.
5.7 EVAPORATION
Evaporative loss from reservoirs is a loss or use that is not typically thought of as a consumptive
use. The increased surface area of a reservoir provides an ideal condition for evaporation to take place.
A similar situation occurs for natural lakes and streams. The seven river basin planning area studies
addressed evaporative loss in varying ways. From the reports and technical memoranda, estimates of
evaporative loss were compiled. For the average or normal condition, it was estimated that reservoir
evaporative loss amounts to about 586,000 acre-feet per year for the state. A more detailed discussion
and breakdown by basin is provided in Chapter 7, Table 7-1. Figure 5–11 shows the locations of selected
reservoirs over 1,000 acre-feet in capacity.
5.8 REFERENCES
American Society of Civil Engineers (ASCE). 1990. Evapotranspiration and Irrigation Water
Requirement. ASCE Manuals and Reports on Engineering Practice No. 70.
Cuenca, Richard H. 1989. Irrigation System Design – An Engineering Approach. Prentice-Hall,
Inc. Englewood Cliffs, New Jersey.
University of Wyoming, Cooperative Extension Service, College of Agriculture. 1999. Resident
Outdoor Recreation for Fremont County, WY. July.
University of Wyoming, Survey Research Center. 1997. Wyoming State Parks and Historic Sites
Survey.
Yellowstone National Park, Visitation Statistics.
http://www.nps.gov/yell/parkmgmt/historicstats.htm
5-235-

FRANNIE
RANCHESTER
DEAVER COWLEY
DAYTON
LOVELL
SHERIDAN
BYRON
POWELL
SHERIDAN
HULETT
PARK
CLEARMONT
BIG HORN
CROOK
CODY
CAMPBELL
GREYBULL
BURLINGTON
BASIN
BUFFALO
Powder/Tongue
SUNDANCE
PINE HAVEN
Wind/Bighorn
GILLETTE
MOORCROFT
MANDERSON
UPTON
WORLAND
TEN SLEEP
JOHNSON
TETON
HOT SPRINGS
WASHAKIE
KIRBY
WRIGHT
KAYCEE
Snake/Salt
JACKSON
THERMOPOLIS
DUBOIS
Northeast
WESTON
NEWCASTLE
MIDWEST
ALPINE
PAVILLION
SHOSHONI
RIVERTON
NIOBRARA
CONVERSE
THAYNE
FREMONT
NATRONA
ROLLING HILLS
HUDSON
PINEDALE
GLENROCK
LANDER
MILLS CASPER
MANVILLE
SUBLETTE
LUSK
AFTON
DOUGLAS
LOST SPRINGS
VAN TASSELL
BIG PINEY
GLENDO
LINCOLN
HARTVILLE
LA BARGE
GUERNSEY
BAIROIL
FORT LARAMIE
COKEVILLE
Bear
Green
MEDICINE BOW
HANNA
KEMMERER
OPAL
RAWLINS
SUPERIOR
SINCLAIR
ROCK RIVER
Platte
PLATTE
WHEATLAND
CHUGWATER
LINGLE
TORRINGTON
GOSHEN
YODER
CARBON ELK MOUNTAIN
LA GRANGE
WAMSUTTER
ALBANY
GRANGER
SWEETWATER
ROCK SPRINGS
GREEN RIVER
SARATOGA
ALBIN
LYMAN
UINTA LARAMIE
LARAMIE
EVANSTON
MOUNTAIN VIEW
BURNS PINE BLUFFS
ENCAMPMENT
CHEYENNE
BAGGS
DIXON
LEGEND
Irrigated Lands
"
Figure 5-1
Irrigated Lands
5-24

FRANNIE
RANCHESTER
DEAVER COWLEY
DAYTON
LOVELL
SHERIDAN
BYRON
POWELL
SHERIDAN
HULETT
PARK
CLEARMONT
BIG HORN
CROOK
CODY
CAMPBELL
GREYBULL
BURLINGTON
BASIN
BUFFALO
Powder/Tongue
SUNDANCE
PINE HAVEN
MANDERSON
GILLETTE
MOORCROFT
Wind/Bighorn
MEETEETSE
UPTON
TEN SLEEP
JOHNSON
WORLAND
TETON
Snake/Salt
HOT SPRINGS
WASHAKIE
KIRBY
WRIGHT
KAYCEE
Northeast
WESTON
NEWCASTLE
THERMOPOLIS
JACKSON
DUBOIS
MIDWEST
ALPINE
PAVILLION
SHOSHONI
RIVERTON
NIOBRARA
CONVERSE
THAYNE
FREMONT
NATRONA
ROLLING HILLS
HUDSON
PINEDALE
GLENROCK
LANDER
MILLS CASPER
MANVILLE
SUBLETTE
LUSK
AFTON
DOUGLAS
LOST SPRINGS
VAN TASSELL
BIG PINEY
GLENDO
LINCOLN
HARTVILLE
LA BARGE
GUERNSEY
BAIROIL
FORT LARAMIE
COKEVILLE
Bear
Green
MEDICINE BOW
HANNA
KEMMERER
OPAL
RAWLINS
SUPERIOR
SINCLAIR
ROCK RIVER
Platte
PLATTE
WHEATLAND
CHUGWATER
LINGLE
TORRINGTON
GOSHEN
YODER
CARBON ELK MOUNTAIN
LA GRANGE
WAMSUTTER
ALBANY
GRANGER
SWEETWATER
ROCK SPRINGS
GREEN RIVER
SARATOGA
ALBIN
LYMAN
UINTA LARAMIE
LARAMIE
EVANSTON
MOUNTAIN VIEW
BURNS PINE BLUFFS
ENCAMPMENT
CHEYENNE
BAGGS
DIXON
LEGEND
Active Irrigation Well
Source: Wyoming State Engineer's Office GIS files compiled June 2006
"
Figure 5-2
Active Irrigation Wells
5-25

FRANNIE
PARK
CODY
Wind/Bighorn
DEAVER
POWELL
COWLEY
RANCHESTER
LOVELL DAYTON
SHERIDAN
SHERIDAN
BYRON
CLEARMONT
GREYBULL
BURLINGTON
BIG HORN
BASIN
MANDERSON
MEETEETSE
Powder/Tongue
BUFFALO
HULETT
CAMPBELL
CROOK
SUNDANCE
PINE HAVEN
GILLETTE MOORCROFT
UPTON
TETON
Snake/Salt
JACKSON
HOT SPRINGS
DUBOIS
WORLAND
JOHNSON
WESTON
TEN SLEEP
NEWCASTLE
KIRBY WASHAKIE
WRIGHT
KAYCEE
EAST THERMOPOLIS
THERMOPOLIS
MIDWEST EDGERTON
Northeast
STAR VALLEY RANCH
ALPINE
THAYNE
AFTON
LINCOLN
SUBLETTE
MARBLETON
BIG PINEY
PINEDALE
FREMONT
RIVERTON
PAVILLION
HUDSON
LANDER
SHOSHONI
NATRONA
BAR NUNN
MILLS
CONVERSE
ROLLING HILLS
EVANSVILLE
GLENROCK
CASPER
DOUGLAS
GLENDO
NIOBRARA
MANVILLE
LUSK
VAN TASSELL
COKEVILLE
Bear
BEAR RIVER
KEMMERER
OPAL
DIAMONDVILLE
GRANGER
UINTA
EVANSTON
LYMAN
LA BARGE
MOUNTAIN VIEW
GREEN RIVER
Green
SUPERIOR
ROCK SPRINGS
SWEETWATER
BAIROIL
WAMSUTTER
RAWLINS
HANNA
CARBON
SARATOGA
ENCAMPMENT
RIVERSIDE
MEDICINE BOW
ELK MOUNTAIN
ROCK RIVER
Platte
ALBANY
LARAMIE
PLATTE
WHEATLAND
GUERNSEY
FORT
LARAMIE
CHUGWATER
LARAMIE
CHEYENNE
LINGLE
TORRINGTON
GOSHEN
YODER
LA GRANGE
BURNS
ALBIN
BAGGS
DIXON
PINE BLUFFS
"
Underlined text denotes first class cities. WS 15-3-101 defines a first class city as having at least 4,000 inhabitants and having made a public proclamation.
LEGEND
Groundwater Surface Water Combination
Figure 5-3
Municipalities and Source of Supply
5-26

FRANNIE
RANCHESTER
DEAVER COWLEY
PARK
LOVELL
DAYTON
SHERIDAN
BYRON
SHERIDAN
POWELL
CLEARMONT
HULETT
BIG HORN
CROOK
CODY
CAMPBELL
GREYBULL
BURLINGTON
SUNDANCE
BASIN
Powder/Tongue
PINE HAVEN
Wind/Bighorn
MANDERSON
WORLAND
BUFFALO
MOORCROFT
GILLETTE
UPTON
JOHNSON
TEN SLEEP
TETON
Snake/Salt
HOT SPRINGS
WASHAKIE
KIRBY
KAYCEE
WRIGHT
Northeast
WESTON NEWCASTLE
THERMOPOLIS
DUBOIS
JACKSON
EDGERTON
MIDWEST
SHOSHONI
ALPINE
PAVILLION
RIVERTON
NIOBRARA
CONVERSE
THAYNE
FREMONT
NATRONA
ROLLING HILLS
HUDSON
EVANSVILLE
PINEDALE
LANDER
MILLS
MANVILLE LUSK
GLENROCK
CASPER
AFTON
SUBLETTE
DOUGLAS LOST SPRINGS
VAN TASSELL
MARBLETON
BIG PINEY
GLENDO
LINCOLN
HARTVILLE
LA BARGE
GUERNSEY
BAIROIL
FORT LARAMIE LINGLE
PLATTE
COKEVILLE
GOSHEN
Bear
Green
HANNA
MEDICINE BOW
Platte
WHEATLAND
TORRINGTON
YODER
DIAMONDVILLE
CHUGWATER
KEMMERER
RAWLINS SINCLAIR
OPAL
ROCK RIVER
SUPERIOR
ELK MOUNTAIN
LA GRANGE
CARBON
ALBANY
SWEETWATER
WAMSUTTER
GRANGER
ROCK SPRINGS
GREEN RIVER
SARATOGA
ALBIN
UINTA LARAMIE
LYMAN
LARAMIE
BURNS PINE BLUFFS
EVANSTON
MOUNTAIN VIEW
ENCAMPMENT
RIVERSIDE
CHEYENNE
BAGGS
DIXON
LEGEND
Municipal Well
Source: Wyoming State Engineer's Office GIS files compiled June 2006. All wells with municipal use in the water right were included.
"
Figure 5-4
Municipal Wells
5-27

FRANNIE
Wind/Bighorn
RANCHESTER
DEAVER COWLEY
DAYTON
LOVELL
SHERIDAN
BYRON
POWELL
SHERIDAN
HULETT
PARK
CLEARMONT
BIG HORN
CROOK
CODY
CAMPBELL
GREYBULL
BURLINGTON
BASIN
BUFFALO
Powder/Tongue
SUNDANCE
PINE HAVEN
MANDERSON
GILLETTE
MOORCROFT
Snake/Salt
MEETEETSE
UPTON
TEN SLEEP
JOHNSON
WORLAND
TETON
HOT SPRINGS
WASHAKIE
KIRBY
WRIGHT
KAYCEE
Northeast
WESTON
NEWCASTLE
THERMOPOLIS
JACKSON
DUBOIS
MIDWEST
ALPINE
PAVILLION
SHOSHONI
RIVERTON
NIOBRARA
CONVERSE
THAYNE
FREMONT
NATRONA
ROLLING HILLS
HUDSON
PINEDALE
GLENROCK
LANDER
MILLS CASPER
MANVILLE
SUBLETTE
LUSK
AFTON
DOUGLAS
LOST SPRINGS
VAN TASSELL
BIG PINEY
GLENDO
LINCOLN
HARTVILLE
LA BARGE
GUERNSEY
BAIROIL
FORT LARAMIE
COKEVILLE
Bear
Green
MEDICINE BOW
HANNA
KEMMERER
OPAL
RAWLINS
SUPERIOR
SINCLAIR
ROCK RIVER
Platte
PLATTE
WHEATLAND
CHUGWATER
LINGLE
TORRINGTON
GOSHEN
YODER
CARBON ELK MOUNTAIN
LA GRANGE
WAMSUTTER
ALBANY
GRANGER
SWEETWATER
ROCK SPRINGS
GREEN RIVER
SARATOGA
ALBIN
LYMAN
UINTA LARAMIE
LARAMIE
EVANSTON
MOUNTAIN VIEW
BURNS PINE BLUFFS
ENCAMPMENT
CHEYENNE
BAGGS
DIXON
LEGEND
!( Domestic Well
Source: Wyoming State Engineer's Office GIS files compiled June 2006. All wells with either domestic or stock uses are shown.
"
Figure 5-5
Domestic Wells
5-28

FRANNIE
Wind/Bighorn
RANCHESTER
DEAVER COWLEY
DAYTON
LOVELL
SHERIDAN
BYRON
POWELL
SHERIDAN
HULETT
PARK
CLEARMONT
BIG HORN
CROOK
CODY
CAMPBELL
GREYBULL
BURLINGTON
BASIN
BUFFALO
Powder/Tongue
SUNDANCE
PINE HAVEN
MANDERSON
GILLETTE
MOORCROFT
Snake/Salt
MEETEETSE
UPTON
TEN SLEEP
JOHNSON
WORLAND
TETON
HOT SPRINGS
WASHAKIE
KIRBY
WRIGHT
KAYCEE
Northeast
WESTON
NEWCASTLE
THERMOPOLIS
JACKSON
DUBOIS
MIDWEST
ALPINE
PAVILLION
SHOSHONI
RIVERTON
NIOBRARA
CONVERSE
THAYNE
FREMONT
NATRONA
ROLLING HILLS
HUDSON
PINEDALE
GLENROCK
LANDER
MILLS CASPER
MANVILLE
SUBLETTE
LUSK
AFTON
DOUGLAS
LOST SPRINGS
VAN TASSELL
BIG PINEY
GLENDO
LINCOLN
HARTVILLE
LA BARGE
GUERNSEY
BAIROIL
FORT LARAMIE
COKEVILLE
Green
MEDICINE BOW
HANNA
Platte
PLATTE
WHEATLAND
LINGLE
TORRINGTON
GOSHEN
YODER
Bear
KEMMERER
OPAL
SUPERIOR
GRANGER
SWEETWATER
ROCK SPRINGS
RAWLINS SINCLAIR
CHUGWATER
ROCK RIVER
CARBON ELK MOUNTAIN
LA GRANGE
WAMSUTTER
ALBANY
GREEN RIVER
SARATOGA
ALBIN
LYMAN
UINTA LARAMIE
LARAMIE
EVANSTON
MOUNTAIN VIEW
BURNS PINE BLUFFS
ENCAMPMENT
CHEYENNE
BAGGS
DIXON
LEGEND
Industrial Well Miscellaneous Well
Source: SEO GIS files compiled June 2006. All wells with industrial and miscellaneous use in the water right were included.
"
Figure 5-6
Industrial and Miscellaneous Wells
5-29

")
")
TETON
Snake/Salt
")
PARK
")
")
Wind/Bighorn
Grand Targhee
Wood River- Meteeste
Jackson Hole Resort
JACKSON
Snow King
Pahashka Tepee area
Sleeping Giant
Togwotee Pass
DUBOIS
CODY
")
POWELL
FRANNIE
DEAVER
BYRON
")
COWLEY
LOVELL
BURLINGTON
HOT SPRINGS KIRBY
")
THERMOPOLIS
Sibley Lake
Antelope Butte
GREYBULL
")
BASIN
BIG HORN
MANDERSON
")
")
Bighorn Mountain Resort
WORLAND
RANCHESTER
DAYTON
Willow Park
")
")
")
SHERIDAN
SHERIDAN
CLEARMONT
")
BUFFALO
Pole Creek
Powder/Tongue
") ")
JOHNSON
CAMPBELL
")
")
CROOK
WASHAKIE
WESTON
KAYCEE
MIDWEST
GILLETTE
WRIGHT
MOORCROFT
PINE HAVEN
")
HULETT
") ")
Northeast
Bear Lodge
UPTON
SUNDANCE
Beaver Creek
")
NEWCASTLE
Alpine to Afton trails system
")
ALPINE
") ")
")
")
THAYNE
")
AFTON
White Pine Lodge
")
PINEDALE
SUBLETTE
PAVILLION
SHOSHONI
FREMONT
")
LANDER
") ")
NATRONA
HUDSON
Afton to Alpine trails system
Sinks Canyon area
Hogadon
RIVERTON
")
MILLS
")")
CASPER
")
ROLLING HILLS
GLENROCK
Casper Mountain
NIOBRARA
CONVERSE
") ")
DOUGLAS
LOST SPRINGS
MANVILLE
")
LUSK
VAN TASSELL
BIG PINEY
GLENDO
COKEVILLE
Bear
LINCOLN
LA BARGE
Pine Creek
")
KEMMERER
Green
OPAL
SUPERIOR
South end of Wind Rivers
BAIROIL
CARBON
MEDICINE BOW
HANNA
RAWLINS
")
SINCLAIR
ROCK RIVER
Platte
PLATTE
")
WHEATLAND
HARTVILLE
")
GUERNSEY
FORT LARAMIE
LINGLE
GOSHEN
YODER
CHUGWATER
") ")
TORRINGTON
")
EVANSTON
GRANGER
UINTA
LYMAN
MOUNTAIN VIEW
Uintas north face
")
GREEN RIVER
")
ROCK SPRINGS
ELK MOUNTAIN
LA GRANGE
WAMSUTTER
SWEETWATER
ALBANY
BAGGS DIXON
")
SARATOGA
ENCAMPMENT
Libby Creek
Snowy Range
Little Laramie
Sierra Madre/Encampment
")
")
LARAMIE
Happy Jack
")
")
")
CHEYENNE
ALBIN
LARAMIE
BURNS PINE BLUFFS
LEGEND
Downhill Ski Area Cross Country Ski Area Golf Course
Source: Wyoming Geographic Information Science Center
Figure 5-7
Ski Areas and Golf Courses
5-30

Wind/Bighorn
PARK
!
Buffalo Bill
Medicine Lodge
"
"
POWELL
SHERIDAN
CAMPBELL
BIG HORN
CLEARMONT
CODY
GREYBULL
BURLINGTON
BASIN
MEETEETSE
FRANNIE
Legend Rock
Connor Battlefield
DEAVER COWLEY
DAYTON
LOVELL
BYRON
SHERIDAN
"
"
BUFFALO
Trail End
Fort Phil Kearny
Powder/Tongue
GILLETTE
MANDERSON
!
MOORCROFT
HULETT
CROOK
SUNDANCE
Keyhole
UPTON
TEN SLEEP
WORLAND
TETON
JOHNSON
Snake/Salt
JACKSON
HOT SPRINGS
DUBOIS
KIRBY
!
THERMOPOLIS
Hot Springs
WASHAKIE
WESTON NEWCASTLE
WRIGHT
KAYCEE
Northeast
MIDWEST
FREMONT
ALPINE
PAVILLION
SHOSHONI
THAYNE
PINEDALE
AFTON
SUBLETTE
MARBLETON
BIG PINEY
LINCOLN
!
"
RIVERTON
HUDSON
Sinks Canyon
!
South Pass City
Boysen
"
NIOBRARA
CONVERSE
NATRONA
ROLLING HILLS
!
Edness Kimball Wilkins CASPER
Independence Rock
GLENROCK
"
DOUGLAS
Fort Fetterman
Wyoming Pioneer Museum
MANVILLE
LOST SPRINGS
!
GLENDO
Glendo
LUSK
!
Guernsey
VAN TASSELL
LA BARGE
COKEVILLE
Bear
Names Hill
!
Green
KEMMERER
OPAL
RAWLINS
SUPERIOR
WAMSUTTER
GRANGER
SWEETWATER
ROCK SPRINGS
BAIROIL
SINCLAIR
"
Seminoe
MEDICINE BOW
HANNA
Fort Fred Steele
PLATTE
WHEATLAND
Platte ! "
HARTVILLE
GUERNSEY
CHUGWATER
ROCK RIVER
CARBON ELK MOUNTAIN
LA GRANGE
ALBANY
"
Fort Laramie
FORT LARAMIE
Oregon Trail Ruts
"
LINGLE
GOSHEN TORRINGTON
YODER
Register Cliff
Bear River
!
EVANSTON
"
Piedmont Kilns
Fort Bridger
GREEN RIVER
SARATOGA
Platte River Crossing
Wyoming Territorial Prison
LYMAN
UINTA LARAMIE
MOUNTAIN VIEW
ENCAMPMENT
BAGGS DIXON
Ames Monument
Curt Gowdy
!
CHEYENNE
Hawk Springs
BURNS PINE BLUFFS
Historic Governors' Mansion
LEGEND
" Historical Site !
State Park
Source: Wyoming Geographic Information Science Center and Wyoming State Parks and Historic Sites
"
Figure 5-8
State Parks and Historic Sites
5-31

Snake/Salt
Wind/Bighorn
Bear
#
Green
#
Black Hills
National Forest
Big Horn National Forest
Yellowstone
National
Park
Grand Teton
National Park
Bridger/Teton
National Forest
Northeast
Thunder Basin
National Grassland
Me dic ine Bow Nationa l Fore st
Shoshone
National
Forest
PARK
CODY
Big Horn
Canyon National
Recreation Area
BURLINGTON
GREYBULL
BIG HORN
BASIN
TETON
HOT SPRINGS
Targhee National Forest
ALPINE
JACKSON
DUBOIS
Wind River
Indian Reservation
KIRBY
THERMOPOLIS
SHOSHONI
MANDERSON
WORLAND
RIVERTON
THAYNE
HUDSON
PINEDALE
LANDER
SUBLETTE
FREMONT
AFTON
MARBLETON
BIG PINEY
LINCOLN
LA BARGE
COKEVILLE
Fossil Butte
National Monument
KEMMERER
OPAL
SUPERIOR
EVANSTON
UINTA
LYMAN
Wasatch
National
Forest
GRANGER
GREEN RIVER
Ashley
National
Forest
SWEETWATER
ROCK SPRINGS
Flaming Gorge
National Recreation Area
WAMSUTTER
LEGEND
# National Monument
RANCHESTER
DAYTON
SHERIDAN
SHERIDAN
BUFFALO
CLEARMONT
Powder/Tongue
GILLETTE
CROOK
Devil's Tower
National Monument
MOORCROFT
UPTON
TEN SLEEP
JOHNSON
CAMPBELL
WASHAKIE
NEWCASTLE
WESTON
WRIGHT
KAYCEE
MIDWEST
NIOBRARA
NATRONA
MILLS CASPER
ROLLING HILLS
GLENROCK
CONVERSE
MANVILLE
LUSK
DOUGLAS
LOST SPRINGS
VAN TASSELL
GLENDO
HARTVILLE
BAIROIL
CARBON
HANNA
RAWLINS SINCLAIR
SARATOGA
ENCAMPMENT
ELK MOUNTAIN
MEDICINE BOW
ROCK RIVER
Platte
GUERNSEY
PLATTE
WHEATLAND
CHUGWATER
FORT LARAMIE
LINGLE
GOSHEN TORRINGTON
YODER
LA GRANGE
ALBANY
LARAMIE
LARAMIE
BURNS
CHEYENNE
ALBIN
PINE BLUFFS
BAGGS
DIXON
"
Figure 5-9
National Parks, Forests, and Monuments
5-32

1
Basin Map Number Stream Basin Map Number Stream
1 Poker Hollow Creek 1 Fish Creek No. 1
2 North Fork Smiths Fork River Snake/Salt River
2 Fish Creek No. 2
3 Water Canyon Creek 3 Greys River
4 Little White Creek 4 Salt River
5 Giraffe Creek 1 Green River
6 Salt Creek 2 North Cottonwood Creek
7 Huff Creek 3 South Cottonwood or Lander Creek
8 Coal Creek 4 West Fork New Fork River
Bear River
9 Smiths Fork 5 North Piney Creek
10 Porcupine Creek 6 Middle Piney Creek
11 Coantag Creek 7 Fish Creek
12 Hobble Creek 8 South Piney Creek
13 Trespass Creek 9 LaBarge Creek
14 Lander Creek 10 Rabbit Creek
15 Raymond Creek 11 Ham's Fork
16 Coal Creek 12 Gilbert Creek IF Seg. No. 1
17 Packstring Creek 13 Little Gilbert Creek IF Seg. No. 1
Northeast Wyoming 1 Redwater Creek 14 East Fork Smith's Fork Creek
Platte River
Wind/Bighorn River
1 Deer Creek 15 Sage Creek IF Seg. No. 1
2 Wagonhound Creek 16 Trout Creek IF Seg. No. 1
3 Camp Creek 17 Red Creek IF Seg. No. 1
4 Nugget Gulch Branch Green River
18 Dirtyman Fork Seg. No. 1
5 Horse Creek 19 Deep Creek Seg. No. 1
6 Beaver Creek 20 Douglas Creek Seg. No. 1
7 Lake Creek 21 Big Sandstone Creek Seg. No. 1
8 Laramie River 22 Mill Creek Seg. No. 1
9 Douglas Creek 23 North Fork Big Sandstone Creek Seg. No. 1
10 North Platte River 24 Roaring Fork L. Snake River Seg. No. 1
11 South Fork of the Grand Encampment River 25 West Fork North Fork Little Snake River
12 Sweetwater River 26 North Fork Little Snake River
13 Rock Creek 27 Solomon Creek
1 Clarks Fork River 28 Deadman Creek
2 Shoshone River No. 1 29 Harrison Creek
3 Shell Creek No. 1 30 Ted Creek
4 Shell Creek No. 2 31 Third Creek
5 Medicine Lodge No. 1 32 Rose Creek
6 Tensleep Creek 33 Granite Gulch/Green Timber
7 Little Popo Agie 34 Pine Creek No. 1 - from Fremont Lake
8 Big Wind River 35 Pine Creek No. 1
9 Currant Creek 1 Little Bighorn River
10 Pickett Creek No. 1 2 Dry Fork
11 Pickett Creek No. 2 Powder/Tongue River
3 Tongue River
12 Francs Fork No. 1 4 Clear Creek No. 1
13 Jack Creek No. 1 5 Clear Creek No. 2
14 West Timber Creek No. 1 6 Middle Fork Powder River
15 Piney Creek No. 1
16 Greybull River No. 1
17 N.F. Pickett Creek No. 1
18 Middle Fork Wood River
19 Wood River above Middle Fork
20 Wood River below Middle Fork
21 South Fork of Wood River
22 Dick Creek
23 Marquette Creek
24 Trout Creek
FRANNIE
DEAVER COWLEY
LOVELL
BYRON
POWELL
1
2
3
RANCHESTER
DAYTON
SHERIDAN
SHERIDAN
HULETT
1
2
TETON
Snake/Salt
JACKSON
PARK
9
DUBOIS
8
24
17
10 11
23
16 13 15 14
12 22
19 20
18 21
2
CODY
Wind/Bighorn
MEETEETSE
BURLINGTON
HOT SPRINGS
BIG HORN
KIRBY
THERMOPOLIS
GREYBULL
BASIN
MANDERSON
WORLAND
3
WASHAKIE
4
5
TEN SLEEP
6
6
4
5
Powder/Tongue
BUFFALO
KAYCEE
CLEARMONT
JOHNSON
MIDWEST
CAMPBELL
GILLETTE
WRIGHT
MOORCROFT
PINE HAVEN
Northeast
CROOK
UPTON
WESTON
SUNDANCE
1
NEWCASTLE
ALPINE
4
3
1
PAVILLION
SHOSHONI
FREMONT
CONVERSE
NIOBRARA
RIVERTON
5
17
6
4
3
7 8
15 16
Bear
THAYNE
AFTON
COKEVILLE
EVANSTON
2
9
1
14
13
12
11
10
11
5
6
7
8
9
12
2
LINCOLN
KEMMERER
3 4
LYMAN
UINTA
MOUNTAIN VIEW
13
OPAL
BIG PINEY
LA BARGE
PINEDALE
GRANGER
LEGEND
Instream Flow Segment
34 35
SUBLETTE
GREEN RIVER
14 15
16
Green
SWEETWATER
ROCK SPRINGS
17
LANDER
HUDSON
7
12
WAMSUTTER
BAIROIL
BAGGS DIXON
RAWLINS
18
19
22
SINCLAIR
21
24
25
CARBON
20
23
10
27
26
NATRONA
SARATOGA
28
29
33
30
31
32
HANNA
RIVERSIDE
ENCAMPMENT
MILLS
ELK MOUNTAIN
"
CASPER
10
MEDICINE BOW
2
9
13
6
7
1
5 4 3
ROLLING HILLS
8
GLENROCK
ROCK RIVER
Platte
ALBANY
LARAMIE
DOUGLAS
LOST SPRINGS
GLENDO
PLATTE
WHEATLAND
GUERNSEY
CHUGWATER
CHEYENNE
MANVILLE
HARTVILLE
LARAMIE
LUSK
FORT LARAMIE
LINGLE
GOSHEN
BURNS
VAN TASSELL
TORRINGTON
YODER
LA GRANGE
ALBIN
PINE BLUFFS
Figure 5-10
Instream Flow Segments
1
5-33

Jackson Lake
TETON
Snake/Salt
Jackson
Palisades
Reservoir
Grassy Lake
Reservoir
PARK
Newton Reservoir
Wind/Bighorn
Dubois
New Fork
Lakes
Buffalo Bill
Reservoir
Lake Creek
Reservoir
Anchor Reservoir
Luce Reservoir
Cody
Lily Pond
Powell
Frannie
Bighorn Lake
Byron
Pilot Butte
Reservoir
Pavillion
BIG HORN
Adelaide Reservoir
Worland
Kirby
HOT SPRINGS
Sawmill Reservoir
Twin Lakes
Burlington
Shell Creek Reservoir
Wiley Lake
Basin
Kearney Lake
Jones Reservoir
Manderson
Cloud Peak
Reservoir
Thermopolis
WASHAKIE
Boysen Reservoir
Willow Park
Reservoir
Dome Lake
Sheridan
JOHNSON
SHERIDAN
Big Goose Park Reservoir
Bighorn Reservoir
Buffalo
Lake DeSmet
Kaycee
Healy Reservoir
Tie Hack Reservoir
Muddy Guard
No. 2 Reservoir
Dull Knife Reservoir
Powder/Tongue
Midwest
CAMPBELL
Gillette
Wright
Northeast
Hulet
CROOK
Keyhole Reservoir
Pine Haven
Moorcroft
Gillette Lake
Betty No. 1
Reservoir
Tract 37
Reservoir
Upton
WESTON
Klodt
Reservoir
Spencer
Reservoir
Sundance
Newcastle
Thayne
Cokeville
Bear
Afton
LINCOLN
Kemmerer
Fremont Lake
South
Boulder Lake
Middle Piney
Reservoir
La Barge
SUBLETTE
Kemmerer Reservoir
Woodruff Narrows Reservoir
Pinedale
Christina Lake
Big Sandy Reservoir
Bull Lake
Reservoir
Shoshone Reservoir
Green
Superior
SWEETWATER
Rock Springs
Lander
Riverton
FREMONT
Frye Lake
Louis Lake
Eden Reservoir East
Wamsutter
Bairoil
Rawlins
Sinclair
NATRONA
Mills
Casper
Gray Reef Reservoir
Alcova Reservoir
Pathfinder Reservoir
Kortes Reservoir
Seminoe Reservoir
Medicine Bow
Wheatland Reservoir No 3
CARBON
Elk Mountain
Rolling Hills
Glenrock
Rock River
Platte
ALBANY
CONVERSE
Douglas
Lost Springs
Glendo
PLATTE
Hartville
Wheatland
NIOBRARA
Manville
Glendo Reservoir
Lusk
Guernsey Ft. Laramie
Wheatland Reservoir No 2
Torrington
GOSHEN
Yoder
Van Tassell
Guernsey Reservoir
Grayrocks Reservoir
La Grange
Evanston
Lyman
Mountain View
UINTA
Austin Reservoir
Green River
Saratoga
Laramie
Flaming Gorge Reservoir
Encampment
Sulphur Creek Reservoir
Lake Hattie
Albin
LARAMIE
Cheyenne
Burns Pine Bluffs
LEGEND
Meeks Cabin Reservoir
Reservoir
Baggs Dixon
"
Figure 5-11
Selected Reservoirs Greater Than 1,000 ac-ft
5-34

6.0 PROJECTIONS
This chapter presents future water demand projections for the state for three growth scenarios
(high, mid, and low). Demographic and economic information is developed and relationships with water
use are established for the various economic sectors within the state. The economic and demographic
data are applied to develop water demand projections for the three growth scenarios.
6.1 FUTURE ECONOMIC AND DEMOGRAPHIC SCENARIOS
6.1.1 Overview of Planning Scenarios
Three alternative planning scenarios were developed for the seven
river basin studies. This development employed various forecasting
approaches that incorporated insights on overall regional growth patterns
from local planning officials and industry representatives. An overview of
each of these scenarios is provided below. More specific details about the
assumptions for the key economic sectors in each river basin and the local
insights on regional growth are provided in the technical memoranda
associated with each of the individual river basin studies.
High Scenario
In the simplest terms, the High Scenario incorporates an estimation of the most growth in each of
the key sectors and in the region that could potentially occur over the forecast horizon.
Mid Scenario
The Mid Scenario represents the assumed most realistic level of growth likely to occur in each of
the key sectors and in the region over the planning horizon. Although the actual economic growth
experienced in the basin may vary somewhat from this projection, the assumed activity levels represent
the rate of growth most likely to be experienced in the river basins and in the state. As such, this scenario
may be the most useful for water planning purposes.
Low Scenario
The Low Scenario embodies the estimated lowest simultaneous growth (or largest contraction)
reasonably likely to occur in each of the key sectors and in the region over the planning horizon.
6.2 AGRICULTURAL DEMAND PROJECTIONS
6.2.1 Introduction
As discussed in Chapter 3, agriculture in Wyoming is dominated by livestock production and this
holds true in all of the seven river basins. Much of the irrigated acreage in Wyoming is devoted to the
production of forage in the form of alfalfa hay, other hay, feed grains, and irrigated pasture.
The factors that will most likely have the largest potential impact on the economic prospects for
state agriculture are the demand for and price of beef. Sales of beef cattle and calves have comprised
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6.0 PROJECTIONS
slightly over 75 percent of total agricultural cash receipts for the period 2000 to 2004 (Equality State
Almanac, 2006). Other potential factors that may significantly impact agriculture include changes in
public land grazing policies, second home and subdivision development, the aging of the ranching
population, and management of cattle range with stockwater supplies. The following are summary
descriptions about prospects for agriculture in Wyoming over the planning horizon under each of the
planning scenarios.
High Scenario
The High Scenario for livestock production reflects what are
considered to be the most optimistic stocking assumptions given production
of feed from irrigated lands and public rangelands and strong demand and
prices for beef, wool, and lamb. Other positive influences on agriculture in
the High Scenario might be slower urban development and land subdivision
or consolidation of ranches; investment in stockwater developments to
increase range productivity; steady prices of inputs like fertilizer; and fewer
cattle from outside areas grazing in the state as state cattle inventories
increase. Sheep inventories would remain constant or decline slightly while
cattle numbers would remain steady or increase, potentially to historic highs
with exception of the Snake/Salt River Basin where all scenarios indicate declines in all livestock
numbers.
Under the High Scenario, irrigated acreage will increase from current levels or remain constant in
all river basins. Increases may be driven by increased production of hay for export as well as to support
the increased livestock. The Wind/Bighorn River Basin will experience the most increase in irrigated
acreage as the Tribal Futures Projects are brought on line and other projects in the basin are developed.
Mid Scenario
The Mid Scenario for livestock production reflects the most realistic stocking assumptions for
lands in Wyoming, given production of feed from irrigated lands and arid rangelands. This scenario also
assumes steady demand and prices for beef, wool, and lamb. Mid Scenario assumptions for agriculture in
Wyoming are moderate urban development and land subdivision or consolidation of ranches; steady
investment in stockwater developments to increase range productivity; and stable prices for inputs like
fertilizer. Across the state, livestock numbers would remain fairly stable. Some river basins will likely
experience continued declines in sheep numbers, or numbers will remain stable as is anticipated in the
Platte River Basin. Most of the river basins will experience steady to slight increases in cattle numbers;
however, the Snake/Salt River Basin is expected to experience declines in both sheep and cattle over the
planning horizon. In the Snake/Salt River Basin, horse numbers make up a larger percentage of total
livestock than in any other basin. Horse numbers are expected to continue to grow in the Snake/Salt
River Basin as the area continues to be a major recreation area with a high demand for recreation horses.
Under the Mid Scenario, irrigated acreage in most of the river basins will remain relatively
constant through the planning horizon. It is expected that most irrigated acreage will remain in
production but that some acreage will be lost as a result of ranch sales to large corporations or to
developers in the areas around Cheyenne, Laramie, and Casper and in the Teton and Lincoln County area.
Ranchers will make up some of these losses by bringing additional acreage under irrigation. In the
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6.0 PROJECTIONS
Wind/Bighorn River Basin, some fairly significant increase may be expected with the development of
some of the Tribal Futures Projects.
Low Scenario
The Low Scenario for livestock production reflects what are considered to be the most pessimistic
stocking assumptions for the state given production of feed from irrigated lands and arid rangelands. This
scenario also assumes weak demand and prices for beef, wool, and lamb. Other negative influences on
agriculture assumed under the Low Scenario are faster urban development and land subdivision or
consolidation of ranches; no investment in stockwater developments to increase range productivity; rising
prices of inputs like fertilizer; and large numbers of outside cattle. Sheep inventories will continue to fall
and cattle numbers will remain steady or decline, potentially to historic lows.
Under the Low Scenario, irrigated acreage will remain constant or decrease from current levels.
The statistics on livestock numbers and irrigated acreage suggest that when economic conditions
deteriorate in the river basin areas, ranchers respond primarily with changes in livestock herds and not as
much with changes in irrigated acreage patterns. Under the Low Scenario, the crop mix is anticipated to
remain unchanged with the highest percent of irrigated acreage planted in alfalfa, other hays, and pasture.
6.2.2 Future Water Needs and Demands
Needs and demands for irrigation water must be
differentiated. A need for additional irrigation water is an
identifiable current or future use that would enhance the economic
well-being of the irrigator and/or the economy of the region as a
whole. Demands are distinguished from needs by the fact that they
are measured in relationship to price. To give a simple example, an
irrigator may need additional irrigation water in a dry year to grow
enough hay to provide winter feed for his cattle. However, if
additional water costs $500 per acre-foot, the irrigator’s demand for additional water would probably be
zero because it would be more cost-effective to either buy additional forage from other producers or
reduce the size of his herd.
In analyzing municipal and industrial water uses, needs and demands are often viewed
interchangeably. The cost of water is usually a relatively minor part of the costs involved in developing
water intensive manufacturing facilities such as electric power plants. As a result, it can be assumed that
industrial users will demand the water that they need to expand production over a reasonable range of
prices. Similarly, municipal needs are usually assumed to be essential and thus will be translated into
demands over a reasonable price range. That convention was used for projecting municipal and industrial
demands. Irrigated agriculture, however, is an industry in which producers are very sensitive to the price
of water, and their demands for water can change dramatically as a function of price.
To determine the level of need and demand for irrigation water, all irrigated lands in the seven
river basins were mapped as part of the river basin planning efforts. Table 6-1 shows the current level of
irrigation in each of the river basins and also shows the projected increase in irrigated acreage for each
basin.
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Table 6-1 Presently Irrigated Acreage and Projected Irrigation Development
30 Year Projections
River Basin Current High Scenario Mid Scenario Low Scenario
acres
Bear 64,000 69,000 61,000
Green 330,000 330,000
Northeast 87,000 87,000
Platte 612,000 649,000 612,000 602,000
Powder/Tongue 170,000 170,000
Snake/Salt 99,000 103,000 87,000 76,000
Wind/Bighorn 1 600,000 810,000 670,000 600,000
Note: Blanks indicate that no data was developed for this scenario.
1 Current Wind/Bighorn figure is modeled irrigated acreage for full-supply scenario and does not include Popo Agie Basin
or Tribal Futures projects.
Irrigation in Wyoming requires large volumes of water, and is the largest single water use in
Wyoming. Irrigation requirements are expressed in terms of diversion requirements and consumptive
irrigation requirements (CIR). Table 6-2 presents the irrigation diversion requirement for each river
basin. Diversion data presented are based on the normal year. Dry year and wet year information is
contained in the individual river basin plans.
Table 6-2 Current and Projected Irrigation Diversions
River Basin
Current
30 Year Projections
Diversions High Scenario Mid Scenario Low Scenario
ac-ft
Bear 1 295,000 312,000 277,000
Green 2
Northeast 152,000 258,000 194,000 152,000
Platte 1,553,000 1,640,000 1,553,000 1,522,000
Powder/Tongue 381,000 594,000 465,000 381,000
Snake/Salt 363,000 382,000 319,000 285,000
Wind/Bighorn 3,278,000 4,070,000 3,549,000 3,278,000
1
A Mid Scenario was not developed in this plan.
2
Diversion data were developed for only those ditches that had measured flow data and are not presented due to the
incomplete nature of the data.
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The CIR or use for each river basin is displayed in Table 6-3.
Table 6-3 Current and Projected Consumptive Irrigation Use
30 Year Projections
River Basin Current Use High Scenario Mid Scenario Low Scenario
ac-ft
Bear 1 95,000 100,000 95,000 89,000
Green 401,000 438,000 423,000 408,000
Northeast 86,000 94,000 91,000 86,000
Platte 663,000 700,000 661,000 650,000
Powder/Tongue 184,000 205,000 194,000 184,000
Snake/Salt 122,000 128,000 107,000 95,000
Wind/Bighorn 1,165,000 1,576,000 1,306,000 1,165,000
1
A Mid Scenario was not developed in this plan. Current use was used in place of the Mid Scenario.
Tables 6-2 and 6-3 present the volumes of water that will be required in each river basin to
provide for the irrigation water needs and demand to satisfy the CIR and the diversion requirement.
6.2.3 Tribal Futures Agricultural Projects
The Wind/Bighorn River Basin shows the greatest potential for new irrigation development. The
tribal awards for future development commonly known as the “Futures Projects” encompass a fairly large
acreage and have an associated senior irrigation diversion right.
As part of the Bighorn Decree (Roncolio, 1982), the Eastern Shoshone and Northern Arapaho
Tribes were awarded Federal Reserved Water Rights for not only lands with existing irrigation, but also
lands that could be economically irrigated as determined through a Potentially Irrigable Acres (PIA)
study. PIA studies have become the benchmark for quantification of Federal Reserved Water Rights
throughout the western United States. A PIA study is a compilation of agronomy, engineering, and
economic analysis that identifies currently undeveloped land that could feasibly be irrigated. The results
of this PIA study were the conceptual development of five projects encompassing approximately 54,000
acres on the Wind River Reservation. The projects, conceptual land area, and awarded diversion
requirement are shown in Table 6-4. Figure 6-1 shows the location of the Futures Projects.
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Table 6-4 Tribal Futures Projects
Awarded (Roncolio, 1982)
Diversion
Land Area Requirement
Land Area
Modeled
Diversion
Requirement
Futures Project acres ac-ft ac-ft/ac acres ac-ft ac-ft/ac
North Crowheart 38,800 147,800 3.8 40,800 155,100 3.8
South Crowheart 4,700 20,100 4.3 5,000 19,700 3.9
Arapahoe 3,800 16,700 4.4 3,800 16,700 4.4
Riverton East 3,800 17,500 4.6 4,000 15,100 3.7
Big Horn Flats 2,700 7,200 2.7 2,800 7,800 2.8
Total 53,800 209,300 3.9 1 56,400 214,400 3.8 1
1 Average Diversion Requirement.
Tribal Futures Projects were included in water supply modeling runs to determine their general
effect on streamflows and other diversions within the WBHB. The data included in the model for the
Futures Projects were developed the same as the other diversion data for the model. An overall efficiency
of 55 percent was utilized for those projects, where conveyance was proposed through open ditches, while
an overall efficiency of 62 percent was used for conveyance through pipelines. Both of these efficiencies
assume improved onfarm applications, such as gated pipe and/or sprinklers as developed in previous
studies for Riverton East (Nelson Engineering, 2001) and the Soil Conservation Service (SCS, 1992).
As shown in Table 6-4, there are slight differences between the awarded and modeled acreages
and diversion requirements for the Futures Projects. The information for the Wind/Bighorn River Basin
plan was developed using the most current reasonable data for climate, crop water requirements, and
anticipated efficiencies for the Projects, thus accounting for the differences in developed values. The
information presented in the Wind/Bighorn River Basin plan regarding Futures Projects is in no way
intended to imply or suggest proposed changes to the decree.
The effects of Tribal Futures Projects on flows within the Wind/Bighorn River Basin and on other
diversions within the basin are more fully described in the Wind/Bighorn River Basin technical
memorandum, “Available Surface Water Determination”. A brief description of each potential Futures
Project within the Wind/Bighorn River Basin is contained in the basin plan. The Arapahoe Irrigation
Project is discussed in the WWDC’s Popo Agie Watershed Study (Anderson Consulting Engineers,
2003).
6.2.4 Irrigable Lands
All of the new irrigation projects identified in the river basin planning area studies are in the
WBHB planning area. New irrigation identified in the other river basin planning areas, is primarily
individual development and on a much smaller scale than in the WBHB.
In addition to Tribal Futures Projects, there are other potential agricultural development projects
within the WBHB that have been discussed over the years. Table 6-5 presents the potentially irrigable
areas. The potentially irrigable areas are also shown on Figure 6-1. The annual CIR and diversion
requirements shown in the table were developed similar to existing irrigated lands.
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Table 6-5 Summary of Potentially Irrigable Lands Within the Wind/Bighorn Basin
Irrigable Annual CIR
Annual Div. Req.
Area Total Unit Total Unit
Basin Name Subbasin acres ac-ft ac-ft/ac ac-ft ac-ft/ac
Bighorn, Polecat Clarks Fork,
Clarks Fork Bench 1 Shoshone 19,200 38,400 2.0 72,960 3.8
North Cody 1 Shoshone 500 850 1.7 1,600 3.2
South Cody 1 Shoshone 2,000 3,400 1.7 6,400 3.2
West Big Horn Lake,
Greybull 1 Greybull 1,000 2,200 2.2 4,300 4.3
Westside 1 Upper Bighorn 11,700 23,400 2.0 45,630 3.9
Bighorn YU Bench 1 Greybull 17,300 29,410 1.7 57,090 3.3
Arapahoe
Little Wind,
Popo Agie 3,800 7,980 2.1 14,820 3.9
Bighorn Flats
Little Wind,
Upper Wind 2,700 4,590 1.7 8,640 3.2
North
Crowheart
Lower Wind,
Upper Wind 38,800 85,360 2.2 162,960 4.2
Riverton
East
Little Wind,
Upper Wind 3,800 7,980 2.1 15,960 4.2
Wind
Sand Mesa 1 Lower Wind 1,700 4,250 2.5 8,330 4.9
South Little Wind,
Crowheart Upper Wind 4,700 9,400 2.0 18,330 3.9
Total (Tribal Futures Projects) 53,800 115,310 2.1 2 220,710 4.1 3
Total (Non-Tribal Futures Projects) 53,400 101,910 1.9 2 196,310 3.7 3
Total 107,200 217,220 2.0 2 417,020 3.9 3
Note: Project names based on general location within WBHB because they are not associated with other previously identified projects.
1
Projects not associated with Tribal Futures.
2 Average Annual CIR.
3
Average Annual Div. Req.
The largest non-Futures Projects irrigable land groups are the Westside Irrigation Project in the
Upper Bighorn River subbasin, lands on the YU Bench in the Greybull River subbasin, and lands on the
Polecat Bench in the Shoshone and Clarks Forks subbasins. More information is contained in the river
basin plan.
Another water use by the agriculture sector is livestock water. While this use is relatively small,
it is closely associated with irrigated agriculture and the production of forage for livestock. Table 6-6
presents estimates of livestock water usage for the three scenarios.
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Table 6-6 Livestock Consumptive Use
River Basin
Current
30-Year Projections
High
Scenario Mid Scenario Low Scenario
ac-ft
Bear 530 610 540 490
Green 1 3,200
Northeast 1 2,900
Platte 6,300 7,600 6,600 5,200
Powder/Tongue 1 2,700
Snake/Salt 470 410 340 210
Wind/Bighorn 1 3,100
1
Current use for these river basin planning areas was estimated based on information in the technical memoranda for
each basin area. Projections for these areas were not prepared as part of the river basin plans for the areas.
6.3 MUNICIPAL AND DOMESTIC DEMAND PROJECTIONS
6.3.1 Introduction
Municipal and domestic use projections were created by combining current use rates with
population projections for each river basin planning area. Current municipal and domestic consumption
or use is described in Chapter 5.
6.3.2 Population Projections
This section presents population projections for the communities and rural areas of the planning
region for the time period from 2000 through 2030 for low, moderate, and high growth planning
scenarios. The projections also provide a basis for assessing water-based recreational resource needs.
Current and Projected Population Estimates
The first step in developing population projections is to estimate current population. Population
estimates for cities and towns were taken from the results of the 2000 census or recent estimates. Because
the geographical boundaries of the river basin planning areas do not adhere to county lines, it was
necessary to adjust the county population estimates from the 2000 census to reflect only the proportion of
each county that lies within each river basin planning area boundary. (Chapter 3 provides more detailed
information.)
The geographical distribution of the current population by county by river basin planning area is
described in the individual river basin plans. The individual river basin plans used or referred to one or
more of the following three population projection methods in developing the individual river basin plan
projections:
! Wyoming Department of Administration and Information (WDAI) projections
! U.S. Census Bureau (USCB) projections
! Historical growth projections
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These three methods were used to generate population forecasts through the year 2030 for
communities and rural areas. The WDAI extended forecasts generally resulted in the smallest population
projections, followed by the USCB projections and the historical growth projections in that order.
Table 6-7 shows the 30-year projected populations of the seven river basins for the high, mid and
low scenarios.
Table 6-7 Actual and Projected Populations
River Basin
30-Year Projections
Population 1 High Scenario Mid Scenario Low Scenario
number of people
Bear 14,550 29,400 21,500 15,100
Green 54,760 91,400 75,000 62,500
Northeast 45,600 75,900 60,700 55,600
Platte 227,330 402,000 343,000 322,000
Powder/Tongue 38,420 52,400 49,100 45,000
Snake/Salt 27,480 75,100 46,700 29,300
Wind/Bighorn 86,050 114,400 94,600 90,400
Total 494,190 840,600 690,600 619,900
1
Individual basin numbers do not total to 493,782, the 2000 census population, due to differences experienced in
disaggregation and assignment of census block data to the river basin areas.
Source: Wyoming Department of Administration and Information, Economic Analysis Division. Profile of General Housing
Characteristics by County and Place, 2000. Census Tracts from 2000 Census of Population and Housing, Census 2000,
U.S. Census Bureau.
WDAI Population Projections
The Economic Analysis Division of the WDAI produces population forecasts for Wyoming
counties, cities, and towns.
The Economic Analysis Division forecasts population only 10 or fewer years into the future
because of the uncertainties associated with such projections. A reasonable set of low growth rate
population projections can be derived by computing the WDAI’s average annual population growth rates
for the river basin planning area by using the most recent forecasts and extending those growth rates
through the planning horizon.
USCB Projections
The USCB periodically produces population forecasts for each of the 50 states using a cohort
survival approach, which is based on births and deaths. USCB forecasts for Wyoming are contained in
two sets of population projections, the Series A and Series B forecasts.
Both series of projections indicate moderate future population growth for Wyoming based upon
migration patterns in the mid-1990s. During that period, there was a moderate influx of new residents
into some parts of Wyoming from elsewhere in the country. The USCB projections are based upon the
assumption that this moderate rate of net in-migration will continue into the future.
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Historical Growth Projections
A third set of population projections was developed from an analysis of historical population
growth. The state experienced rapid population growth during the 30-year period from 1970 through
2000. A reasonable set of high growth population projections can be developed by assuming that the
absolute population growth that occurred during that period will occur during the next 30 years.
Economic Base Methodology
The economic and demographic projection approach employs an established technique in
regional economics known as “economic base analysis”. The economic base approach is a “bottom-up”
method that focuses directly on specific activities that are likely to drive economic and demographic
changes in the future, while at the same time being less data-intensive than econometric modeling
approaches.
A modified version of the economic base forecasting approach was used in some of the river
basin plans. A more detailed discussion of the population projection technique used in each river basin
plan is included in the final river basin plans and the associated technical memorandum.
6.3.3 Municipal and Domestic Use Projections
Current per capita use rates for municipal water consumption are presented in Chapter 5. These
rates were applied to population projections for incorporated cities and towns in the planning area to
estimate future municipal use. For purposes of projecting future use, small, unincorporated areas were
included in the domestic demand projections. A more detailed discussion, of both municipal and
domestic use, is contained in the seven river basin plans.
Table 6-8 shows the projected municipal and domestic water use for the High, Mid, and Low
Scenarios.
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Table 6-8 Projected Municipal and Domestic Water Use
River Basin
High
Scenario
30-Year Projections
Mid
Scenario
Surface Water (ac-ft)
Low
Scenario
Bear 4,700 3,400 2,400
Green 24,500 22,500 21,000
Northeast 0 0 0
Platte 33,500 28,400 26,600
Powder/Tongue 10,000 9,300 8,600
Snake/Salt 0 0 0
Wind/Bighorn 18,000 14,900 14,200
Total 90,700 78,500 72,800
Groundwater (ac-ft)
Bear 1,500 1,100 900
Green 3,700 3,500 3,000
Northeast 15,900 12,700 11,600
Platte 11,200 9,500 8,900
Powder/Tongue 3,300 3,200 2,800
Snake/Salt 18,600 11,500 7,200
Wind/Bighorn 8,500 7,000 6,700
Total 62,700 48,500 41,100
Note: None of the municipal or rural domestic water systems in the Northeast Wyoming River Basin
or in the Snake/Salt River Basin use surface water.
Source: River basin plans and associated technical memoranda.
Under the Mid Scenario, it is projected that in 30 years the state will require about 64,000 acrefeet
of surface water to satisfy the municipal and domestic water demands. The largest basin in terms of
municipal and domestic water demand is the Platte River Basin, and it will annually need to supply over
28,000 acre-feet of consumptive use.
Municipal and domestic groundwater use for the state under the Mid Scenario will require about
48,500 acre-feet to satisfy the projected municipal and domestic water demand. The largest basin in
terms of municipal and domestic consumptive groundwater demand is the Northeast Wyoming River
Basin with a Mid Scenario demand of about 12,700 acre-feet annually in 30 years.
As can be seen from Table 6-8, the state will need to supply a considerably larger amount of both
surface water and groundwater under the High Scenario to satisfy municipal and domestic needs and
demands over the 30-year planning horizon.
6.4 INDUSTRIAL DEMAND PROJECTIONS
Current industrial water uses are described in Chapter 5. This section presents projections of
industrial water needs for the 30-year planning period. These projections provide a basis for gauging the
adequacy of current water supplies in the individual river basin planning areas and the state to meet
potential future needs. Projections were developed for high, mid, and low level growth scenarios.
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6.4.1 Future Coal-fired and Natural Gas-fired Electric Power Production
Several companies have announced plans to build additional
generating capacity in the Northeast Wyoming River Basin, and those
plans are in various stages of implementation. The plans for plants involve
dry cooling towers and limited usage of groundwater for process purposes.
Water requirements for dry-cooled plants are less than for plants with wet
cooling towers which are in use at other locations, including the Dave
Johnston Power Plant in Converse County, Laramie River Station in Platte
County, Naughton Power Plant in Lincoln County, and Jim Bridger Power
Plant in Sweetwater County. While wet-cooled plants are more efficient and less costly to run than drycooled
plants, their water requirements are much larger. Given the fact that there is relatively little
surface water available in proximity to the coal resources of Northeast Wyoming, it appears likely that
dry cooling will remain the technology of choice in Northeast Wyoming for power production for the
foreseeable future.
In the Green River Basin, the expansion would be wet-cooled plants supplied by surface water
from the Green River.
The most agressive development in the Platte River Basin would include the addition of natural
gas-fired generation capacity and coal conversion. This additional capacity would be two wet-cooled
plants.
In the Powder/Tongue River Basin, additional generating capacity would be wet-cooled and
likely associated with Lake DeSmet Reservoir where substantial volumes of water are available.
The Wind/Bighorn River Basin is the remaining basin where coal or natural gas-fired generation
capacity might be built. The development of two coal-fired power plants and two natural gas-fired power
plants would be wet-cooled.
The Bear River Basin and the Snake/Salt River Basin will not likely see any development of coalfired
or natural gas-fired electrical power generation during the planning period.
Projections of future water needs for electric power generation are described below for high,
moderate, and low growth scenarios. The Northeast Wyoming projections are based upon the assumption
that dry cooling and limited groundwater pumping for process water will continue to be the predominant
technology employed. An added assumption for the High and Mid Scenarios is that the transmission
bottleneck out of Wyoming will be eliminated and thus encourage the construction of additional electrical
generating capacity.
High Scenario
In the Green River Basin, the High Scenario assumes that in addition to a 1,000 MW expansion
of the Jim Bridger Power Plant, a new 3,000 MW coal-fired generating facility will be built in the vicinity
of coal deposits near Creston Junction, using water piped from the Green River. This will require an
additional 68,700 acre-feet of cooling water.
The High Scenario for electric power production in Northeast Wyoming assumes that 2,390 MW
of planned capacity addition will take place, and that an additional 1,200 MW of capacity not yet
announced will be added to help meet the nation’s growing energy needs. This additional capacity may
require the adoption of new emissions control technology to meet air quality standards or the relaxation of
those standards to allow increased production, neither of which is assured. Nevertheless, the addition of
3,590 MW of generating capacity constitutes a reasonable High Scenario forecast for Northeast
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6.0 PROJECTIONS
Wyoming. Under all scenarios the 33 MW Osage Power Plant is assumed to be retired. Total generating
capacity for the High Scenario in Northeast Wyoming is 4,020 MW, and total water requirements would
be about 10,100 acre-feet annually. Using wet cooling technology for the new capacity would bring total
water requirements to slightly over 70,000 acre-feet annually.
The Platte River Basin High Scenario assumes the development of 1,000 MW of natural gas-fired
generation capacity plus 500 MW of coal-based generation capacity. The 500 MW of generation capacity
are associated with a coal conversion plant that will produce about nine million barrels of diesel fuel per
day. The natural gas-fired power plant will require about 10,000 acre-feet of water annually. The coal
conversion plant will require about 15,000 acre-feet per year.
In the Powder/Tongue River Basin the High Scenario assumes the development of 2,000 MW of
coal-fired generation capacity in the area of Lake DeSmet Reservoir. With the relatively cheap and
already developed water in Lake DeSmet, it is likely that a 2,000 MW plant will be built during the
planning period. This plant will be wet-cooled and will require about 34,000 acre-feet of water annually.
The High Scenario for the Wind/Bighorn River Basin assumes that there will be two 200 MW
coal-fired power generating plants built in the basin and that there will be two 500 MW natural gas-fired
power plants built in the basin during the planning period. The two coal-fired plants would require 8,000
acre-feet of water while the two natural gas-fired plants would require 10,000 acre-feet of water annually.
The Bear River Basin and the Snake/Salt River Basin are not projected to have any coal-fired or
natural gas fired electrical power generation development during the 30-year planning period.
Future electric power generation water use projections for the High Scenario are presented in
Table 6-9.
Mid Scenario
The moderate growth scenario is based upon the reasonably foreseeable possibility that cogeneration
facilities will not be developed at a rate sufficient to meet regional power needs over the next
30 years.
In the Green River Basin, the logical location for a moderate expansion of generating capacity is
the Jim Bridger Power Plant near Point of Rocks, east of Rock Springs. The facility was originally
designed for up to six 500 MW coal-fired generating units, although only four such units have been
installed. The existing units are among the most cost-efficient in the Rocky Mountain Power generating
system, and an expansion to six coal-fired units at Jim Bridger would be a logical step to increase regional
power production in a cost-effective manner. The moderate growth scenario for electric power
production in the basin projects a 50 percent increase in water requirements for the Jim Bridger Power
Plant over the next 30 years, with water requirements at the Naughton facility remaining constant at
current levels. Total water use for the moderate growth scenario is projected to grow from a current rate
of 47,800 acre-feet annually to approximately 65,000 acre-feet in 30 years.
The moderate growth scenario for electric power production in Northeast Wyoming River Basin
assumes that the permitting and financial uncertainties surrounding future expansion will be resolved over
the next 30 years and that all currently planned capacity additions will be online by then. In that case,
2,390 MW of additional generating capacity would be in place by the year 2030, bringing the total to
2,820 MW. If dry cooling technology is used, total water requirements would be about 6,900 acre-feet
annually. If wet cooling technology is used for new generating units, total water requirements would rise
to about 41,100 acre-feet annually.
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6.0 PROJECTIONS
Table 6-9 Projected Electrical Generation Water Needs
30-Year Projections
River Basin
Type of
Generation
Existing
Generation
Capacity
Additional Projected Generation
Capacity
High
Scenario
Mid
Scenario
Low
Scenario
Cooling Water
Total Use - Surface Water
High
Scenario
Mid
Scenario
Low
Scenario
High
Scenario
Cooling Water
Total Use - Groundwater
Mid
Scenario
MW 1 MW 1 ac-ft ac-ft
Bear None 0 0 0 0 0 0 0 0 0 0
Green Coal 2,700 4,000 1,000 0 116,500 65,000 47,800 0 0 0
Northeast 2 Coal 500 3,600 2,400 1,200 0 0 0 10,100 6,900 3,700
Platte
Low
Scenario
Coal 2,500 500 0 0 15,000 31,900 31,900 0 0 0
Natural Gas 0 1,000 1,000 0 10,000 10,000 0 0 0 0
Powder/Tongue Coal 0 2,000 1,000 0 34,000 17,000 0 0 0 0
Snake/Salt None 0 0 0 0 0 0 0 0 0 0
Wind/Bighorn
Coal 0 400 200 0 8,000 4,000 0 0 0 0
Natural Gas 0 1,000 500 0 10,000 5,000 0 0 0 0
Total 5,700 12,500 6,100 1,200 193,500 132,900 79,700 10,100 6,900 3,700
MW = megawatts
1
2 The 33MW Osage Power Plant is assumed to be retired
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6.0 PROJECTIONS
The Platte River Basin Mid Scenario assumes that a 1,000 MW natural gas-fired power plant is
constructed in the 30-year planning period. This plant would require 10,000 acre-feet of cooling water.
In the Powder/Tongue River Basin for the Mid Scenario, it is assumed that a 1,000 MW coalfired
power plant is constructed near Lake DeSmet Reservoir. The annual water need for this plant is
17,000 acre-feet.
The Mid Scenario for the Wind/Bighorn River Basin assumes that there will be a 200 MW coalfired
power generating plant built in the basin and that there will be a 500 MW natural gas-fired power
plant built in the basin during the planning period. The coal fired plant would require 4,000 acre-feet of
water while the natural gas-fired plant would require 5,000 acre-feet of water annually.
Future electric power generation water use projections for the Mid Scenario are presented in
Table 6-9.
Low Scenario
In the Green River Basin, the Low Scenario for future power
generation projects current levels of water consumption for power generation
to remain constant over the next thirty years (approximately 47,800 acre-feet
annually).
The Low Scenario is based upon the assumption that additional power
needs in the western U.S. over the next 30 years will be met by the
construction of new generating facilities outside of the basin, possibly cogeneration
facilities developed in conjunction with industrial plants in other
states.
The Low Scenario for Northeast Wyoming future electric power production assumes that only 50
percent of the 2,390 MW of announced new capacity will eventually be built. That additional capacity
would bring total generating capacity in the planning area to 1,625 MW during the 30-year planning
period. If dry cooling technology is used, total annual water use for power generation would rise to about
3,700 acre-feet annually. Almost all of this water would be supplied by ground water wells. If low cost
surface water or CBM water were available in sufficient quantities to make wet cooling technology
practical for the new plants, water consumption would rise to about 20,800 acre-feet annually.
The Low Scenarios for the Platte River, Powder/Tongue River, and Wind/Bighorn River Basins
assume that no new-coal fired or natural gas-fired power generation capacity is developed.
Future electric power generation water use projections for the Low Scenario are presented in
Table 6-9.
6.4.2 Coal, Uranium, and Miscellaneous Mining
Coal
Wyoming is the number one coal-producing state with the bulk of Wyoming’s coal being mined
in the Northeast Wyoming River Basin planning area. Northeast Wyoming has enormous resources of
low-sulfur, low-BTU coal that can be mined from the surface due to relatively shallow overburden.
During the year 2000, there were 14 active mines in the planning area with a total annual production of
322.7 million tons.
These coal mines use water primarily for dust abatement and reclamation, with lesser amounts
used for equipment wash-down and typical sanitary purposes. The primary sources of water for most
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mines are dewatering wells drilled into the coal seam ahead of advancing pit operations and sump wells to
remove water from the pit. A few mines are extracting dry coal, however, and have drilled groundwater
wells away from the coal seam to meet their needs.
In the Green River Basin, coal is produced primarily to supply the two coal-fired electric
generation plants. During the year 2000, there were two active mines in the planning area with a total
annual production of almost 13.7 million tons. Coal mining water uses in the Green River Basin are very
similar to the uses in the Northeast Wyoming River basin.
In the Platte River Basin, there were two active coal mines at the start of the planning period,
however, one is in the process of closing and going into reclamation. In 2000 these two mines produced
about 2 million tons of coal.
The remaining river basin with coal-producing potential is the
Powder/Tongue River Basin. This basin presently has no active producing
mines.
Future water use by the coal industry is expected to increase slightly for
two reasons. First, the pits at some mines are expanding away from the coal
processing facilities onsite, thus requiring longer hauls and more water use for
dust suppression. Second, some mines anticipate expanding production in the
future if coal prices remain firm at current levels or increase. Nevertheless, most
mines will continue to meet their operational water needs from dewatering wells
and sumps on site. These activities are not expected to affect either surface water
resources or other groundwater users.
Uranium
Uranium has been mined in several of the river basin planning areas. The only active uranium
mines are in the Platte River Basin. It is projected in the High Scenario that Jackpot Mine above
Pathfinder Reservoir will reopen and an in situ mine will open in the Gas Hills area of the Wind/Bighorn
River Basin. The Kennecott Uranium Company is not anticipated to reopen its mine in the Great Divide
Basin of the Green River Basin planning area.
Miscellaneous Mining
Other minerals that are mined in Wyoming are bentonite, gypsum, aggregates, sand, and gravel.
Active bentonite and gypsum mining is primarily located in the Wind/Bighorn River Basin. Small
mining operations, extracting aggregate, sand, and gravel, are widely scattered across the state and use
varying but small amounts of water.
6.4.3 Oil Production and Refining
All but three of the counties in Wyoming have active crude oil production. In 2000 Wyoming
produced 60,607,000 barrels of crude oil. Production dropped to 51,651,000 barrels in 2004 (Equality
State Almanac, 2006). This is consistent with the long-term trend of declining oil production in
Wyoming. In addition to the actual extraction of the oil, the state also has oil refining capabilities. The
bulk of the refineries are located in the Platte River Basin.
Water use in this sector varies across the state but typically is relatively minor. Water is often
produced as a by-product of oil extraction. This water is reinjected, used for enhanced oil recovery, or
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discharged. The companies also drill water wells to provide water for enhanced recovery of oil. Actual
water withdrawals are not monitored so the actual amount of water used or discharged by the industry is
difficult to determine. Approaches to estimating water use for oil production and refining in the seven
river basin areas differ considerably. Detailed information on the approach used and results are contained
in the individual river basin plans and associated technical memoranda.
6.4.4 Coalbed Methane and Natural Gas Production
Natural gas and coalbed methane (CBM) development use little water in exploration and
production. CBM usually produces water during the methane extraction process.
CBM production has become widespread in the Northeast Wyoming River Basin and the
Powder/Tongue River Basin over the past few years and is expected to increase in the future. CBM
development is not a consumptive user of water resources but produces groundwater as a by-product of
gas production. The process involves pumping water from coal seams to relieve pressure on methane gas
so that it can be captured at the surface. The availability and disposal of CBM process water present both
problems and opportunities in the formulation of a water plan. Figure 6-2 shows the locations of CBM
wells and development areas.
In the Northeast Wyoming River Basin Plan, projected CBM water production for Northeast
Wyoming was expected to reach a peak of about 55,000 acre-feet annually by the year 2004. Production
was expected to remain at that level for about five years and then drop off to less than 2,000 acre-feet
annually by the year 2019.
In the Powder/Tongue River Basins Plan, projected water production for Powder/Tongue River
Basin CBM wells was expected to reach a peak of about 190,000 acre-feet annually by the year 2005.
Production was expected to remain at that level for about five years, and then drop off to less than 25,000
acre-feet annually by the year 2019. More recent studies by the Wyoming State Geological Survey
(Trihydro, 2005) reduced previously published estimates for CBM production through 2010. Figure 6-3
shows the historical and projected numbers of producing
wells and production from that report. Figure 6-4 shows
the cumulative production of both water and gas from
CBM development. Significant volumes of water have
been produced by this industry. Figure 6-5 shows the
CBM production regions and the volumes of water and
CBM that have been produced.
If the dramatic projected drop-off in CBM
production water occurs as indicated in the Northeast
Wyoming River Basin and the Powder/Tongue River
Basin, it poses problems for the potential use of CBM
production water for industrial purposes such as electric power generation. Most large industrial facilities
have design lives of 35 to 50 years or longer, while the projections show that large amounts of CBM
water will be available for only a relatively short period.
At least one power company has expressed an interest in using CBM water for cooling purposes
in Northeast Wyoming. There are several potential problems with implementing such a proposal,
however. One problem is the life expectancy of the resource as mentioned above. Also, the CBM
industry is composed of a large number of companies. Organizing those individuals and companies and
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6.0 PROJECTIONS
providing the infrastructure needed to transport a consistent volume of water to a site for cooling purposes
could prove to be a daunting challenge. Nevertheless, the potential use of CBM water for industrial
purposes remains an interesting possibility.
The Green River and the Wind/Bighorn River Basins are just entering the CBM production arena.
The Bureau of Land Management (BLM) has projected that employment in this sector in the Great Divide
Basin of the Green River Basin could approach 3,300 jobs during the planning period.
Natural gas is produced in all but three counties in Wyoming. Natural gas production is reported
in thousands of MCF (MCF is thousand cubic feet). In 2000, Wyoming produced 1,454,793 thousand
MCF of natural gas. Natural gas production increased to 1,927,837 thousand MCF in 2004 (Equality
State Almanac). Experts anticipate that natural gas production across the state will continue to increase as
it has over the past 20 years. However, some of the minor natural gas producing counties will see
declines in production over the 30-year planning period.
6.4.5 Coal Conversion Facilities
Several companies have studied the possibility of building coal conversion facilities in Campbell
County over the past 20 years. There appear to be two rationales for such facilities. One rationale is the
fact that coal contains a high percentage of water by weight, meaning that eliminating or reducing the
water content of coal prior to shipment could result in substantial savings in transportation costs to out-of
-state utilities and other users. The second rationale is that the vast coal reserves of the region could be
used to produce synthetic versions of fuels such as gasoline if petroleum prices were to increase or
government programs were in place to stimulate domestic energy production.
Since 1980, three coal conversion facilities have been planned for Northeast Wyoming and have
been issued construction permits by the Wyoming Industrial Siting Administration, although none have
been built to date. The Platte River Basin also has potential for a coal conversion plant.
For the low growth scenario, it was assumed that the market forces that have prevented the
construction of such facilities in the past would continue throughout the 30-year planning period.
For the moderate growth scenario, it was assumed that two such facilities would become
operational in the Northeast Wyoming River Basin, one to convert coal to solid fuels and one to convert
coal to liquid fuels. The water requirements of the two plants are 2,200 acre-feet annually. This demand
would probably be met from groundwater sources.
The high growth scenario assumes that in addition to the coal conversion facilities described
above, one coal-to-gasoline plant will become operational in Northeast Wyoming over the next 30 years.
This plant would have an annual consumptive water use requirement of approximately 5,000 acre-feet,
bringing total Northeast Wyoming water use for the high growth scenario to 7,200 acre-feet annually.
This requirement would most likely be met from groundwater sources. In the Platte River Basin, a coalto-diesel
fuel plant would be constructed over the next 30 years. The plant would also generate electrical
power. Annual water consumption would be 15,000 acre-feet (as shown in Table 6-9).
6.4.6 Soda Ash Production
Soda ash is produced only in the Green River Basin planning area. One of the major uses of soda
ash is in the production of glass. The Green River Basin is the site of five industrial facilities that convert
trona to soda ash. As a group, these five facilities produced approximately 11.7 million tons of soda ash
in 1999 and consumptively used about 17,900 acre-feet of water from the Green River. Not all of this
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6.0 PROJECTIONS
water is used in soda ash production or related work; some soda ash facilities use cooling water for onsite
electric power generation and sell their excess power. Total industry water usage in 1999 for all purposes
was estimated at about 18,100 acre-feet annually.
Future growth in soda ash production in the Green River Basin will be largely dependent upon
foreign export markets. U.S. consumption has been relatively flat in recent years and is expected to grow
by only 1.0 to 1.5 percent annually for the foreseeable future. This relatively low growth rate is
attributable to the fact the U.S. market is relatively mature in terms of per capita consumption of soda ash
products.
Foreign demand for soda ash, especially in developing countries, is expected to increase at a more
rapid rate than in the U.S. over the next 30 years. As disposable income rises in developing countries,
consumption of beverages in glass containers is expected to become commonplace. The increased use of
glass containers in foreign markets is expected to translate into increased demand for U.S. soda ash
because the U.S. has the world’s largest deposits of trona and is the lowest-cost producer of soda ash.
Other factors that affect future U.S. soda ash production include trade barriers that many
countries have established to protect their domestic soda ash industries. Over the next 30 years, there is
the potential for lowering trade barriers and opening up new markets for U.S. soda ash. Soda ash exports
from the Green River Basin may also receive a boost from future cost savings in the production (using
solution mining) and transportation of soda ash.
Three scenarios for future water needs for the Green River Basin’s soda ash industry are
described below.
High Scenario
The high growth scenario for soda ash production in the Green River Basin, projects increasing
efficiencies in production and transportation through solution mining and competition in rail
transportation of the finished product. If trade barriers to U.S. exports of soda ash are gradually lowered
or eliminated over the next 30 years, Wyoming producers could be expected to benefit enormously
because they have a competitive advantage with respect to production costs that few other suppliers can
equal. The high growth scenario for Wyoming producers is based upon the assumption that they could
reasonably capture one-third of the total world market of 53.8 million tons by the year 2030.
If domestic production grows at 1.25 percent annually and that exports grow to one-third of
foreign consumption by the year 2030, total estimated soda ash production in the Green River Basin
would be 28.1 million tons in 30 years. If 50 percent of the increased production comes from solution
mining (750 gallons per ton) and 50 percent from conventional processes (450 gallons per ton), the
increase in annual water requirements for the industry by the year 2030 would be 30,200 acre-feet. Total
water requirements for the industry would be 48,300 acre-feet annually, an increase of 167 percent over
current levels.
Mid Scenario
The moderate growth scenario projects no significant changes in the structure of domestic or
international markets for soda ash over the next 30 years. This scenario projects the possibility that
producers will be able to achieve an additional competitive advantage in the export marketplace through
reductions in rail transportation costs and the implementation of solution mining for a portion of their
future production.
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6.0 PROJECTIONS
Wyoming producers could reasonably expect to increase their share of foreign market penetration
from 20 to 25 percent, meaning that total foreign sales would approach 13.5 million tons annually by the
year 2030. If domestic sales continue to grow at the projected rate of 1.25 percent per year, total soda ash
production would be 23.8 million tons by the year 2030, an increase of 12.1 million tons over current
levels.
For purposes of estimating water requirements for this scenario, it was assumed that 50 percent of
future production increases would come from solution mining and that solution mining techniques would
require 750 gallons of water per ton of soda ash production. Based upon these assumptions, the
consumptive use of water by soda ash industry in the Green River Basin would grow by 22,300 acre-feet
annually by the year 2030 to a total of 40,400 acre-feet. This figure represents a 123 percent increase
over current water consumption levels.
Low Scenario
The low growth scenario for future soda ash production projects no significant changes in the
structure of domestic or international markets for soda ash over the 30 year planning period, and no
significant changes in production and transportation costs for Wyoming producers. Under these
conditions, Green River Basin producers would be expected to maintain their current shares of both
domestic and international markets, and their production would be expected to grow proportionally to
growth in consumption. The overall future growth rate for soda ash production in the basin is projected to
be 1.75 percent annually for the low growth scenario.
Based upon industry interviews, the overall average consumptive use rate for current production
in the Green River Basin is approximately 450 gallons of water per ton of soda ash production. This
figure was used to project future water requirements for the industry for the low growth scenario.
At a 1.75 percent annual growth rate, soda ash production in the Green River Basin will grow
from 11.7 million tons in 1999 to 20.0 million tons by the year 2030. The production increase of 8.3
million tons annually will require approximately 11,500 acre-feet of water. That increase would bring
total consumptive use up to 29,600 acre-feet by the year 2030, an increase of 64 percent over current
levels.
6.4.7 Miscellaneous Industry
Miscellaneous industrial use is generally an unverifiable use throughout Wyoming. Most of this
use is assumed to remain constant over the 30-year planning period. Miscellaneous use includes sugar
refineries, hydroelectric and wind generation plants, chemical plants, fertilizer plants, and new industry.
There are three sugar refineries in Wyoming, one in the Platte River Basin and two in the
Wind/Bighorn River Basin. Based on interviews in the Platte River Basin, the High Scenario assumes a
10 percent increase in production and water use. The Low Scenario assumes a 10 percent decline in
production and water use. In the Mid Scenario, it is assumed that production and water use will remain
constant over the planning period.
In the Wind/Bighorn River Basin, it is anticipated that the two sugar refineries, located in
Worland and Lovell will continue to operate at current levels for all three scenarios.
Hydroelectric power generation is a nonconsumptive use but does provide employment and a
resource to the economy of the state. The U.S. Bureau of Reclamation (USBR) operates plants at 13
sites; six are located in the Platte River Basin, six in the Wind/Bighorn River Basin, and one in the Green
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6.0 PROJECTIONS
River Basin. Several small private hydroelectric plants are located throughout the state. In addition to the
hydroelectric plants, there are two wind farms generating electricity from wind power. One is located in
the Bear River Basin, and one is located in the Platte River Basin.
Chemical plants in Wyoming are not large and do not consume large amounts of water.
Examples of chemical plants include the Wyoming Ethanol plant in Torrington and the Dyno Nobel
ammonium nitrate plant near Cheyenne. Similar assumptions were made for future operation of these
plants. In the High Scenario, a 10 percent increase in production and water use would occur; in the Low
Scenario, a 10 percent decrease in production and water use would occur; and in the Mid Scenario, they
would hold steady.
FS Industries operates a fertilizer plant in Rock Springs and is supplied water by the Joint Powers
Water Board. This industry presently consumes about 560 acre-feet annually. In the High Scenario, it is
anticipated that this use could go to 1,500 acre-feet annually. In the Mid Scenario, use would increase to
1,000 acre-feet annually. In the Low Scenario, use would remain steady at present levels.
6.4.8 Industrial Summary
Industrial water use projections for Wyoming described
above focus on existing industries and their future water needs. The
potential for new industries to locate in the state to take advantage of
available water resources also merits discussion. According to the
U.S. Census Bureau (USCB), four industry groups account for over
95 percent of all of the industrial water used in this country each
year. These industries are electric power producers, chemical and
allied products manufacturers, primary metals producers, and paper and allied products manufacturers.
Electric power producers alone consume over 80 percent of all industrial water used in this country each
year. The other three industry groups account for roughly 14 percent of all industrial water use.
Wyoming is already well represented with respect to electric power production and chemical
manufacturers (the soda ash, phosphate, and ammonium nitrate industries fall into this group). It appears
likely that any new water-intensive industrial developments over the next 30 years will fall into the
electric power generation and/or chemical products categories. The other two intensive water use
industries, primary metals and paper producers, tend to locate near the source of their largest process
inputs -- metals and wood, respectively.
The possibility remains that new industrial water uses not discussed in this report will develop
over the next 30 years; however, the nature and extent of such developments is not foreseeable at this
time, and water requirements for such developments are not included in these projections.
Table 6-10 shows the projected industrial demands over the 30-year planning period. It can be
easily seen that industrial use varies greatly across the state. It should also be noted that some small
unquantified mining use has not been included in all basin projections due to lack of data and small
volume of use. In the Wind/Bighorn River Basin water rights were used to estimate and project use. This
likely overstates actual consumptive use somewhat in that basin.
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Table 6-10 Total Industrial Water Demand Projections
River Basin
30-Year Projections
High Scenario Mid Scenario Low Scenario
ac-ft
Bear 500 0 0
Green 166,300 106,400 78,000
Northeast 1 17,300 9,100 3,700
Platte 115,800 92,500 75,300
Powder/Tongue 35,000 17,000 0
Snake/Salt 50 48 24
Wind/Bighorn 115,000 106,000 92,000
Total 449,950 331,048 249,024
1 In Northeast Wyoming, industrial water use is assumed to use dry cooling technology. If wet
cooling is used, then demands would increase to 77,200 for the High Scenario; 20,800 for the
Low Scenario; and 43,300 for the Mid Scenario.
6.5 RECREATIONAL DEMAND PROJECTIONS
6.5.1 Introduction
The tourism and recreation sector is important throughout the state and contributes to sales,
income, and employment in two of the state’s large economic sectors--retail trade and services. As
tourism and recreation contribute to providing jobs and income for the state, the effects on economic and
population projections are captured in the municipal and rural domestic projections. More importantly,
tourism and recreation create notable consumptive and nonconsumptive demands on water in Wyoming
for golfing, alpine skiing, angling, boating, swimming, waterskiing, and enjoying amenities such as
creeks, rivers, lakes, reservoirs, and the scenery and habitats that accompany them.
It was assumed that local, state, and federal agencies will continue to develop and maintain
recreational amenities across the state to take advantage of water resources. No new reservoirs or other
large water-based recreational facilities were identified in the river basin plans. However, water-based
recreation activities were noted to be on the rise in some sectors in some river basins. Examples are
guided angling and river floating. While travel, tourism, and recreation are important to the economy of
the state and the individual river basin planning areas, some river basin planning areas lack large
destination tourist attraction.
6.5.2 Future Recreational Demand
Future demands for recreational water resources in Wyoming depend upon numerous factors,
including population growth, tourism growth, and participation rates in various water-based recreational
activities. Future participation rates depend upon changes in preferences over time as well as the
availability of water resources and the amount of congestion encountered at recreational sites. Changes in
future recreational preferences are hard to predict, so the projections described in this section are based
upon the assumption that participation rates remain constant over the planning period. This assumption
means that projected recreational demands are proportional to growth in population and tourism in the
respective basins.
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Projections of population growth are summarized in Table 6-11 in terms of average annual
growth rates for the high, low, and mid growth planning scenarios. Table 6-11 also projects tourism
growth over the planning period for the three scenarios. The other information needed to project future
recreation demand is a breakdown of recreational activity between residents and nonresidents. No precise
estimates exist, but based upon what information is available and the judgment of professionals in the
WGFD, it was assumed that 80 percent of future hunting and fishing activity would be by Wyoming
residents and 20 percent by nonresidents.
Table 6-11 Projected Annual Growth Rates: Population and Tourism
River Basin
Average Annual Population Growth
Rates - Percentage
High
Scenario
Mid
Scenario
30-Year Projections
Low
Scenario
Bear 2.31 1.25 0.05
Average Annual Tourism Growth
Rates - Percentage
High
Scenario
Mid
Scenario
Low
Scenario
Green 1.35 0.68 0.08 3 2 1
Northeast 1.51 0.75 0.52 3 2 1
Platte 1.92 1.38 1.17
Powder/Tongue 1.04 0.82 0.53 3 2 1
Snake/Salt 3.41 1.78 0.21
Wind/Bighorn 0.91 0.32 0.00 3 2 1
Note: Tourism and recreation growth rates were not estimated for the Bear River Basin, the Platte River Basin, and the
Snake/Salt River Basin.
This information was used to project future water-based recreational activity days for four river
basin planning areas over the 30-year planning period. Those projections are given in Table 6-12. The
demand for still water fishing in the planning areas is projected to expand significantly over the next three
decades. Similar increases are projected for stream fishing demands. The demand for waterfowl hunting
is also expected to increase, but at a lesser growth rate than for fishing.
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Table 6-12 Current and Projected Water-Based Recreational Activity Days
River Basin 1
Green
Northeast
Powder/Tongue
30-Year Projections
Activity Current High Scenario Mid Scenario Low Scenario
number of days
Still water fishing 485,000 868,800 685,300 547,000
Stream fishing 281,700 531,400 414,500 326,900
Waterfowl
hunting 10,600 17,600 14,100 11,500
Still water fishing 50,000 93,000 72,000 62,000
Stream fishing 15,000 28,000 22,000 19,000
Waterfowl
hunting 3,000 5,000 4,000 3,500
Still water fishing 132,000 208,000 183,000 159,000
Stream fishing 140,000 221,000 194,000 169,000
Waterfowl
hunting 2,000 2,700 2,500 2,300
Fishing 2 488,000 722,000 577,000 488,000
Wind/Bighorn
Waterfowl
hunting 28,500 79,000 61,500 28,500
1 Water-based recreational activity days were not developed and projected for the Bear River Basin, the Platte River Basin, and the Snake/Salt River
Basin.
2
Fishing in the Wind/Bighorn River Basin was not broken out into still water fishing and stream fishing.
In the Platte River Basin and in the Snake/Salt River Basin, projections of water consumption
were prepared for golf course irrigation and snowmaking for alpine skiing. These projections are shown
in Table 6-13. This effort was not conducted for the remaining river basin planning areas.
Table 6-13 Current and Projected Water Consumption for Golf and Skiing
River Basin
Activity
Current
High
Scenario
30-Year Projections
Mid
Scenario
Low
Scenario
Golf Course Irrigation 4,400 6,300 5,000 4,400
Platte Alpine Skiing Snowmaking 10 10 10 10
Golf Course Irrigation 880 1,440 1,240 880
Snake/Salt Alpine Skiing Snowmaking 60 140 100 60
ac-ft
Total 5,350 7,890 6,350 5,350
6.5.3 Adequacy of Existing Resources
The WGFD in the past has estimated the supply of water resources available to meet the demands
of fishermen in various regions of the state. These supply estimates were expressed in terms of fishermen
days, and reflect the amount of pressure the WGFD believed that publicly accessible fisheries could
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6.0 PROJECTIONS
withstand without significant deterioration. Although these estimates have not been updated in the past
decade, they serve as one benchmark for judging the capacity of fisheries in the planning area to meet
projected future demands. Unfortunately, the WGFD did not estimate fishery supplies separately for each
river basin planning area. The Powder/Tongue, Little Missouri, Belle Fourche, Cheyenne, and Niobrara
River Basins were grouped together as were the Green and Bear River Basins. Nevertheless, it is useful to
review these supply estimates as background for assessing resource adequacy.
According to the WGFD, the Powder/Tongue and Northeast Wyoming planning areas combined
provide an annual supply of 405,000 activity days of fishing opportunities. With the exception of
Keyhole Reservoir, almost all of this supply is located in the Powder/Tongue River Basin. When this
figure is contrasted with a current utilization rate of 272,000 activity days in the Powder/Tongue Basin, it
is apparent that there is no current overall shortage of angling opportunities. Individual waters may
experience overcrowding at times, however, because they are easily accessible.
The projections of future demands for fishing
opportunities in the Powder/Tongue Basins (Table 6-12)
range from 328,000 to 429,000 activity days annually over
the planning period, depending upon the growth scenario
used. These scenarios indicate that fishing pressure
demands may approach the supply of resources available in
the two river basin planning areas over the next 30 years.
The implications of this conclusion are limited by the fact
that there is a relatively fixed supply of streams in the area
that are suitable for maintaining recreational fisheries. One
inference that can be drawn is that future activities that would denigrate existing recreational stream
fisheries could have significant negative recreational effects, while activities that enhance fisheries habitat
could have significant positive effects.
According to the WGFD, the Green River Basin and the Bear River Basin combined provide an
annual supply of 1,122,800 activity days of lake and reservoir fishing opportunities. Almost all of this
supply is located in the Green River Basin. When contrasted with current utilization rates of about
485,000 activity days of use annually, it is apparent that there is no current shortage of still water angling
opportunities in the Green River Basin. This observation is consistent with the fact that the region is
endowed with numerous lake and reservoir fisheries ranging from small alpine lakes in the higher
elevations of the Bridger-Teton National Forest to Flaming Gorge and Fontenelle Reservoirs in the lower
part of the basin.
Projections of future demands for still water fishing opportunities in the Green River Basin (Table
6-12), range from 547,000 to 870,000 activity days annually over the planning period, depending upon
the growth scenario used. None of these projections approach the estimated supply of over 1.1 million
angling days, meaning that the supply of lake and reservoir fishery resources in the basin should be
adequate to meet projected needs for the foreseeable future. Another inference that can be drawn from
these projections is that private landowners who control access to good-quality stream fisheries in the
basin own a valuable asset and may be able to derive income in the coming decades by allowing access to
those fisheries, either through private leases, leases to public agencies such as the WGFD, or daily access
fees.
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6.0 PROJECTIONS
The other water-based recreational pursuit for which demand projections were developed is
waterfowl hunting. Those projections indicate that demand is expected to rise from the current level. The
WGFD has not estimated the supply of waterfowl hunting opportunities in the basins, partially because
populations are migratory and hunting seasons and bag limits are established in accordance with
guidelines established by the U.S. Fish and Wildlife Service (USFWS).
6.6 ENVIRONMENTAL DEMAND PROJECTIONS
Current environmental uses of water in Wyoming are described in Chapter 5. Those uses include:
! Instream flows and reservoir bypasses
! Minimum reservoir pools
! Maintenance of wetlands, riparian habitat, and other wildlife habitat
Environmental water requirements are not necessarily related to changes in population or tourism.
Instead, environmental water requirements are at least partially a function of human desires concerning
the type of environment in which people want to live. These desires are expressed in many ways,
including environmental programs and regulations promulgated by elected representatives at the state and
federal levels. Thus, future environmental water requirements will be determined, at least partially, by
existing and new legislation dealing with environmental issues at the state and federal levels, and how
that legislation is implemented by federal and state agencies.
Future water requirements for instream flows depend largely upon how Wyoming’s instream flow
legislation is implemented over the 30-year planning period. Projecting the outcome of this process
quantitatively would be difficult and is perhaps unnecessary because instream flows and other
environmental water uses are largely nonconsumptive. Instream flow designations can conflict with
potential new out-of-stream uses at specific locations, however, a topic that is discussed below.
6.6.1 Instream Flows
Wyoming’s instream flow statutes recognize the economic fact that water resources have value in
nonconsumptive uses such as instream flows. Such flows not only contribute to aesthetic character and
biological diversity of the river basin planning areas; they also support recreational fisheries that are
important to river basin residents and to the river basin and state economies.
The WGFD has a goal of maintaining and enhancing existing fisheries through the statutory
designation of instream flow segments and other management strategies. Through 2006, a total of 100
instream flow applications have been filed with the SEO. The WWDC has completed 83 instream flow
feasibility studies. The extent to which current filings and future instream flow requests may conflict
with potential storage developments for supplemental irrigation water is unknown, but the potential for
conflicts does exist. These conflicts would have to be resolved on a case-by-case basis, weighing the
potential benefits to the state of instream water uses versus out-of stream consumptive in- state water
uses.
6.6.2 Minimum Reservoir Pools
Another environmental water use is the provision of minimum reservoir pools for fish and
wildlife purposes. Six reservoirs in the Powder/Tongue River Basin have minimum pools listed in their
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6.0 PROJECTIONS
permitting documents: Park, Dull Knife, Willow Park, Kearney, Cloud Peak, and Tie Hack. Five
reservoirs in the Green River Basin have similar permit conditions: Big Sandy, Boulder, Flaming Gorge,
Fontenelle, and High Savery. In the Wind/Bighorn River Basin, the USBR has five reservoirs that have
conservation pools that include fishery and wildlife uses as well as water quality and recreation: Bighorn
Lake, Boysen Reservoir, Buffalo Bill Reservoir, Bull Lake Reservoir and Pilot Butte Reservoir. The
USBR also operates Jackson Lake to provide a minimum pool for fisheries and other uses. The USBR
also operates seven dams in the Platte River Basin. Given the current federal regulatory environment and
public desires to maintain and enhance recreational fisheries in the Platte Basin, it is likely that any
additional storage developed in the future will have a portion of its storage devoted to fish and wildlife
purposes.
6.6.3 Minimum Releases and Reservoir Bypasses
Another tool for maintaining fisheries habitat in the river basin planning areas is the provision of
minimum flow bypasses at reservoir sites or minimum releases from storage. The seven river basin
reports indicate that currently there are three reservoirs in the Powder/Tongue River Basin that have
minimum flow bypasses, four in the Green River Basin, one in the Snake/Salt River Basin, three in the
Wind/Bighorn River Basin, and five in the Platte River Basin. The development of additional reservoir
storage in the future would likely bring about requests by the WGFD and others for such minimum flow
bypass requirements. As discussed elsewhere, the likelihood of additional storage being developed in the
planning area will be greatly influenced by future trends in cattle and forage prices and state funding
mechanisms available to irrigators in need of supplemental water.
The USBR is aware of the WGFD’s desire to have a 280 cfs minimum flow just below Jackson
Lake Dam. The USBR strives to meet or exceed this amount with its winter releases. A meeting is held
each fall among the USBR, the SEO, and the WGFD to determine the winter release schedule for Jackson
Lake Dam.
6.6.4 Wetlands and Wildlife Habitat
Another important environmental use of water in
the river basin planning areas is the provision of habitat for
wildlife. Wildlife habitat exists in wetland and riparian
areas on public and private lands throughout the state,
some of it occurring naturally and some of it as a result of
human activity. A tabulation of wetlands wildlife habitat
areas in the planning areas has been undertaken as a part of
the geographical information system developed for this
study. A description of the information in this database is
contained in separate technical memoranda.
Three federal programs, the Conservation Reserve Program (CRP), the Wetlands Reserve
Program (WRP), and the Wildlife Habitat Incentives Program (WHIP) encourage the development of
wildlife habitat on private lands. The CRP is administered by the Farm Service Agency of the U.S.
Department of Agriculture (USDA) and provides incentive payments for various conservation practices
that will enhance wildlife habitat, as well as improve water quality and reduce erosion. The WRP is
administered by the Natural Resources Conservation Service (NRCS) of the USDA. It is a voluntary
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6.0 PROJECTIONS
program that provides financial and technical assistance to private landowners to reestablish wetlands on
their property. The WHIP is also administered by the NRCS, and it provides technical and financial
assistance to private landowners interested in improving wildlife habitat on their property. None of these
programs result in significant amounts of consumptive water use. As a result, no projections of future
water needs for such programs were developed as a part of this water plan.
In the Bear River Basin, a fairly large area has been designated as the Cokeville Meadows
National Wildlife Refuge. If fully developed as recommended by the USFWS, the refuge would cover
about 26,657 acres. This area contains significant wetland areas and areas that are presently hay
meadows. Full implementation of the refuge could impact irrigated agriculture and irrigation
consumptive use. This was considered in the agriculture demand projections above.
6.6.5 Direct Wildlife Consumption
As stated in Chapter 5, if all river basin planning areas are assumed to be the same as the Green
River Basin, use would be about 3,500 acre-feet annually. This level of consumptive use is projected to
remain relatively small and unchanged over the planning period.
6.7 SUMMARY OF FUTURE WATER DEMAND PROJECTIONS
Table 6-14 presents the projected demands for the four major water-using sectors in Wyoming for
each scenario, high, mid, and low. Recreational consumptive water use projections were not prepared in
the Bear River, Green River, Northeast Wyoming, Powder/Tongue, or Wind/Bighorn River Basin
planning areas.
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6.0 PROJECTIONS
Table 6-14 Projected Annual Total Consumptive Water Demands
Type of Use
Agriculture Municipal & Domestic Industrial Recreational
30 Year Projections 30 Year Projections 30 Year Projections 30 Year Projections
Low
Scenario
Mid
Scenario
High
Scenario
Low
Scenario
Mid
Scenario
High
Scenario
Low
Scenario
Mid
Scenario
High
Scenario
Low
Scenario
Mid
Scenario
High
Scenario
River Basin
ac-ft ac-ft ac-ft ac-ft
Bear 1 100,000 94,500 88,900 6,200 4,500 4,700 500 0 0
Green 438,000 423,000 408,000 13,700 11,500 9,700 166,300 106,400 78,000
Northeast 75,700 72,800 69,500 15,900 12,700 11,600 17,300 9,100 3,700
Platte 700,000 661,000 650,000 44,600 37,800 35,400 115,800 92,500 75,300 6,300 5,000 4,400
Powder/Tongue 205,000 194,400 183,800 13,300 12,400 11,400 35,000 17,000 0
Snake/Salt 128,100 107,100 94,900 18,600 11,500 7,200 50 48 24 1,600 1,300 950
Wind/Bighorn 2 1,576,400 1,305,700 1,165,500 26,500 21,900 21,000 115,000 106,000 92,000
Total 3,223,200 2,858,500 2,660,600 138,800 112,400 101,000 449,900 331,000 249,000 7,900 6,300 5,400
In the Bear River Basin study, a Mid Scenario was not completed for agriculture. In this table the Mid Scenario is estimated based on the current uses.
1
2 Wind/Bighorn River Basin Industrial use and projections are based on water rights rather than actual consumption. This tends to over state oil and gas industry use as well as other uses.
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6.0 PROJECTIONS
Table 6-15 presents the current and projected future water demands for each of the seven river
basin planning areas and a total for the state for all sectors. These projections are presented by future
scenario. The table presents both surface water and groundwater demands (demands presented in Table
6-15 may be compared to legally available flows as shown in Table 7–2).
River Basin
Table 6-15 Summary of Current and Projected Future Water Uses
Water
30-Year Projections 1
Source Current Use 1 High Scenario Mid Scenario Low Scenario
Bear 2 99,300 108,900 103,200 100,100
Green 609,500 766,700 681,500 630,900
Northeast 92,500 99,200 96,300 93,000
Surface
Platte Water
780,700 962,000 898,200 883,200
Powder/Tongue 207,600 267,200 237,300 209,300
Snake/Salt 194,200 202,200 179,300 168,100
Wind/Bighorn 3
1,329,200 3,053,800 1,501,100 1,318,400
Total Surface Water 3,313,000 5,460,000 3,696,900 3,403,000
Bear 2 3,000 3,600 2,600
Green 800 1,100 1,100 900
Northeast 30,500 56,300 44,100 35,200
Platte Groundwater 124,400 126,100 118,500 100,900
Powder/Tongue 2,500 3,300 3,200 2,800
Snake/Salt 6,800 18,700 11,700 7,400
Wind/Bighorn 3
6,400 8,500 7,000 6,700
Total Groundwater 174,400 217,600 185,600 156,500
1 Includes reservoir evaporation as a use.
ac-ft
2
In the Bear River Basin study, a Mid Scenario was not completed for agriculture. Includes agriculture estimate.
3
Wind/Bighorn River Basin industrial use and projections are based on water rights rather than actual consumption. This tends to over state oil and gas industry use
as well as other uses.
6.8 REFERENCES
Anderson Consulting Engineers. 2003. Popo Agie Watershed Plan. Prepared for
Wyoming Water Development Commission.
Economic Analysis Division. 2006. Equality State Almanac.
Nelson Engineering. 2001. Riverton East Irrigation Project, Level II Feasibility Study.
Prepared for the Wyoming Water Development Commission.
Roncolio, Teno. 1982. Report Concerning Reserved Water Right Claims By and On
Behalf of the Tribes of the Wind River Indian Reservation, Wyoming. Civil Case No. 4993,
District Court of the Fifth Judicial District, State of Wyoming. December 15.
Trihydro Corporation. 2005. Platte River Basin Plan Final Report. De Bruin Interview.
Soil Conservation Service (SCS) 1992. Interim Irrigation On-Farm Report for Wind
River Basin Water Supply Study (DRAFT).
Trihydro Corporation. 2005. Platte River Basin Plan Final Report. De Bruin Interview.
6-30-6-

Powell
Polecat Bench
Byron
Lovell
North Cody
BIG HORN
PARK
Cody
South Cody
Greybull
West Greybull
Burlington
YU Bench
Basin
Manderson
Meeteetse
Westside
Worland
WASHAKIE
HOT SPRINGS
Kirby
Thermopolis
Sand Mesa
Pavillion
Shoshoni
Riverton
FREMONT
Hudson
Lander
LEGEND
Wind River Indian
Irrigable Lands
Tribal Futures
Reservation Boundary Projects
Note: A dot denotes the general location of irrigable lands.
6-31
"
Figure 6-1
Tribal Futures Projects
and Irrigable Lands

6-32

6-33

6-34

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7.0 AVAILABILITY
uses.
This chapter presents estimates of the availability of surface water and groundwater for future
7.1 SURFACE WATER
7.1.1 Introduction
The following subsections describe the analysis of existing surface water data, creation of
spreadsheet-based surface water models, and use of the models’ output to estimate water availability. The
modeled results described herein denote physical availability over and above existing uses, which is to be
distinguished from legal or permitted availability. As projects are proposed in the future, surface water
physical availability will be reduced due to environmental and administrative requirements. However,
physical availability is the important first step in assessing the viability of any future project. Lack of
physical availability of water for a project is an obvious fatal flaw for any water development.
7.1.2 Methodology
The physical availability of surface water was determined through the construction and use of
spreadsheet simulation models that calculate water availability based on the physical amount of water
present at a specific node or location less historical diversions, compact requirements, and minimum
flows. The determination of available surface water is broken down into the following seven
components:
! Compilation of historic streamflow records.
! Study period selection.
! Data extension.
! Estimating natural flow at ungaged model nodes.
! Determining streamflows during wet, normal, and dry years.
! Spreadsheet model development and calibration.
! Determination of physically present surface water.
The Guidelines for Development of Basin Plans (WWDC, 2001) recommends that for the
purposes of the river basin planning process, a hydrologic analysis be conducted for three periods using
average dry year conditions, average normal year conditions, and average wet year conditions. Therefore,
each hydrologic region in a basinwide model has three associated spreadsheet models representing those
three hydrologic conditions. The gaged flows used in the spreadsheet model are developed by averaging
recorded monthly streamflows for groups of years falling into those three hydrologic categories during a
consistent period of record.
To determine the study period, historic streamflow records were analyzed for each basin. In the
selection process, major events that would have affected streamflow were considered. These events were
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7.0 AVAILABILITY
minimized to the extent possible, but it is impossible to find a period in which there were no significant
events. Each of the river basin planning areas had a slightly different study period. The study periods
used are shown below.
Bear 1971-1998
Green 1971-1998
Northeast Wyoming 1970-1999
Platte 1972-2001
Powder/Tongue 1970-1999
Snake/Salt 1971-2001
Wind/Bighorn 1973-2001
The periods selected from 1970 through 2001 contain
extended periods of dry years including some of the driest years of
record as well as periods of normal and wet hydrologic conditions
throughout the river basin planning areas. These study periods also
have the greatest abundance of recorded streamflow data and ditch
diversion data and therefore require less data synthesis. A study period
from the 1970 through 2001 time frame was therefore selected
independently for each river basin planning area as appropriate for
purposes of water availability modeling for the individual river basin
plan.
A more detailed discussion and supporting documentation for the selection of the individual study
periods and the modeling are provided in the “Surface Water Hydrology” technical memoranda for each of
the river basin planning areas.
7.1.3 Surface Water Model
The WWDC has undertaken river basin planning efforts throughout Wyoming. The purpose of
the statewide planning process is to provide decision-makers with current, defensible data to allow them
to manage water resources for the benefit of all the state's citizens. Spreadsheet models were developed to
determine average monthly streamflow in the basin during wet, normal, and dry years. The purpose of
these models was to validate existing basin uses, assist in determining the timing and location of
water physically available for future development, and help to assess impacts of future water supply
alternatives.
The WWDC specified that the river basin models be consistent and use software available to the
average citizen. Accordingly, Excel was selected as the software to support the spreadsheet modeling
effort. The spreadsheet model developed for the Bear River, the first basin plan undertaken, became a
template for subsequent river basin modeling, and new features were added as unique circumstances were
encountered in the basins.
Model Overview
For six modeled river basin planning areas and subbasins, three models were developed,
reflecting each of three hydrologic conditions: dry, normal, and wet year water supply. The Platte River
Basin planning area was not modeled as information was available from litigation and negotiation. The
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7.0 AVAILABILITY
spreadsheets each represent one calendar year of flows, on a monthly time step. The modelers relied on
historical gage data to identify the hydrologic conditions for each year in the study period.
A detailed description of the modeling effort for each of the six modeled river basin planning
areas is contained in the hydrology technical memorandum for each of those basin planning areas.
Model Structure and Components
Each of the subbasin models is a workbook consisting of numerous individual pages
(worksheets). Each worksheet is a component of the model and completes a specific task required for
execution of the model. There are five basic types of worksheets:
! Navigation Worksheets: are Graphical User Interfaces (GUIs) containing buttons used to
move within the workbook.
! Input Worksheets: are raw data entry worksheets (USGS gage data or headwater inflow
data, diversion data, etc.).
! Computation Worksheets: compute various components of the model (gains/losses).
! Reach/Node Worksheets: calculate the water budget node by node.
! Results Worksheets: tabulate and present the model output.
Each river basin planning area was delineated into river or stream reaches and nodes. The choice
of nodes must consider the objectives of the study and the available data. It also must contain all the
water resource features that govern the operation of the basin.
Stream Gage Data
Monthly stream gage data were obtained from the Wyoming Water Resources Data System
(WRDS) and the USGS for each of the stream gages used in the model. Linear regression techniques were
used to estimate missing values for the many gages that had incomplete records. The Mixed Station
Model developed by the USGS was used to perform the regression and data filling. Once the gages were
filled in for the study period, monthly values for dry, normal, and wet conditions were averaged from the
dry, normal, or wet years of the study period. The dry, normal, and wet years were determined on a
subbasin level from indicator gages in each subbasin. The model uses estimated flow at ungaged
headwater nodes as if they were gages.
Additional information on stream gage data and data extension is contained in the hydrology
technical memorandum for each of the six modeled river basin planning areas.
Diversion Data
Surface water diversions are primarily for agricultural use. If actual diversion data existed for a
modeled stream, that information was used in the modeling effort. However, because actual diversion
records were unavailable in some basins, estimates of diversions were made, or the model simulated the
depletion based on the consumptive portion of the diversion being taken from the stream. In river basin
planning areas where this technique was used, the model treats this quantity as if it was the diverted
amount and it is referred to as "diversion data," although it is a depletion quantity.
Data on the diversion data sheet are used to calculate ungaged reach gains and losses, and in some
cases, inflow at ungaged headwater nodes. They are also used as the diversion demand in the
Reach/Node worksheets.
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Reach Gain/Loss
The models simulate major diversions and features of the basins, but minor water features such as
small tributaries lacking historical records and diversions for small permitted acreages are not explicitly
included. Some features are aggregated and modeled, while the effects of many others are lumped
together using a modeling construct called "ungaged reach gains and losses." These ungaged gains and
losses account for all water in the water budget that is not explicitly named.
7.1.4 Supply Estimates
An output worksheet in each spreadsheet model summarizes
monthly flow at the downstream end of each reach and provides the
basis of this analysis. In general, simulated flow at the reach
terminus indicates how much water is physically present, but it may
not fully reflect flow that is available for future appropriation. This
apparently "available flow" may already be appropriated to a
downstream user, may be allocated downstream to satisfy compact
or decree obligations, may be satisfying an instream flow right, or
may result from reservoir storage water being delivered to specific points of diversion downstream. In
short, it is important to acknowledge these existing demands when determining developable flow.
To determine how much of the physical supply is actually developable for future uses, physical
supply at a reach terminus must be reduced to provide for the following circumstances:
! assumed approval of pending instream flow right applications.
! deliveries of storage water.
The flow that is physically present and could be developed for future uses at each point is defined
as the minimum of the physical supply value, adjusted to take into account the above-listed instream
demands, and the adjusted physically present flow at all downstream reaches. In other words, if
adjusted physical supply at the node is the limiting value, then all that water can be removed from the
stream without impacting either instream demand at this location, or downstream appropriators. Thus,
water available for future appropriation must be defined first at the most downstream point, with upstream
availability calculated in stream order. These calculations were made on a monthly basis, and annual
availability was computed as the sum of monthly available water. Calculating annual availability in this
way can yield a different value than applying the same logic to annual flows for each reach. The
summation of monthly values is more accurate, reflecting constraints of downstream use on a monthly
basis.
The physically available supply adjusted for downstream demands and delivery of storage water
is further subject to compact limitations. The limitation is on basinwide annual use, based on total annual
flow at the state line. In some parts of the basin, the compact may be more limiting than the amount of
water unappropriated within Wyoming. Furthermore, availability across the entire basin, once the
compact is considered, may be less than the combined available supplies as defined by the spreadsheet
analysis.
As virgin flow estimates were not prepared in the seven river basin plans, a comparison of present
flows to current levels of depletion was made. Table 7-1 shows the flows that were estimated for the
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7.0 AVAILABILITY
average or normal hydrologic condition. These flow estimates were reduced by the current depletions
estimated in the seven river basin planning area plans. In the 1973 Framework Water Plan, depleted
streamflow leaving Wyoming was estimated at 14,740,200 acre-feet. From Table 7-1, it can be seen that
the depleted streamflow leaving Wyoming has diminished somewhat. The reduction in streamflow
leaving the state can be attributed to increased consumptive use and possibly a drier study period. Direct
comparison of the 1973 Framework Water Plan hydrology to the 1970 to 2001 hydrology was not done in
the individual river basin plans.
Table 7-1 Average Annual Streamflow and Uses - Normal Condition
Basin
GREAT BASIN
Depletions of Streamflow to Wyoming
State Line
Depleted
Outflow -
Municipal,
Streamflow
Natural
Domestic,
Reservoir
Leaving
Conditions 1 Irrigation 2 & Stock 2 Industrial 2 Evaporation 2 Total 2 Wyoming 3
ac-ft
Wyoming's
Remaining
Share
Under
Compact
Bear River 526,000 92,300 1,400 300 5,300 99,300 426,700 187,800
COLORADO RIVER
Green River 4 2,616,500 401,000 20,900 66,300 121,300 609,500 2,007,000 221,300
MISSOURI RIVER
Northeast
Wyoming 5 240,500 69,000 0 0 23,500 92,500 148,000 9,800
Platte River 6 1,307,400 477,300 19,300 70,300 213,800 780,700 526,700 0
Powder/Tongue
River 982,600 184,000 12,300 0 11,300 207,600 775,000 248,100
Wind/Bighorn
River 4,628,600 1,165,500 9,300 15,700 138,700 1,329,200 3,299,400 2,491,500
Yellowstone
River 7 3,149,600 3,149,600 0
COLUMBIA RIVER
Snake/Salt River 8 3,540,000 122,000 0 0 72,200 194,200 3,345,800 155,000
Total 16,991,200 2,511,100 63,200 152,600 586,100 3,313,000 13,678,200 3,313,500
1 Estimates are based on outflow plus depletions from the current river basin plans.
2 Depletion estimates are from the current river basin plans.
3 Depleted flows are based on outflow estimates from the current river basin plans.
4
Depletions for municipal, domestic, and stock include 14,400 acre-feet diverted to the N. Platte for City of Cheyenne use.
5 Excludes the flows for the Little Missouri and Niobrara Rivers.
6 The Platte River system is fully appropriated in that a water supply that is based on a water right with a current-day priority cannot be expected to provide a
reliable supply due to water rights administation. Estimates exclude the flows and depletions from the Horse Creek and South Platte drainages.
7 Drainage area is within Yellowstone National Park and includes estimates for the Madison, Gibbon, Firehole, and Gallatin Rivers.
8
Excludes the flows for the Henrys Fork and Teton Rivers.
The methodology used in the basin studies to evaluate Wyoming’s remaining share under the
interstate compacts and decrees was coordinated through the Wyoming State Engineer’s Office (SEO)
and relies heavily on previous work performed by others on behalf of the State. A more detailed
evaluation was beyond the scope of the river basin planning effort. The methodology employed provides
estimates of Wyoming’s allocation under each of the three hydrologic conditions (wet, normal, and dry
years). With the exception of the Platte River Basin, the basin planning efforts determined the three
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hydrologic conditions. A detailed description of this work is contained in the hydrology technical
memoranda associated with the individual plans.
7.1.5 Basin Supply Estimates
The following subsections contain basin planning area presentations of the physically available
flows and legally available flows. Physically available flows were determined for all of the river basin
planning areas except the Platte River. Legally available flows were not estimated for all of the river
basin planning areas, therefore, Figures 7-1 through 7-7 present physically available flow. The planning
area flows for all of the basins except the Platte River Basin are shown in Table 7-2. The flow estimates
were prepared for three hydrologic conditions: wet, normal, and dry. More detailed discussions of
hydrology for each of these six basins are contained in the basin plan final reports and technical
memoranda.
Bear River Basin
The Bear River Basin planning area flows are shown in Table 7–2. The physically available
flows and legally available flows were prepared for three hydrologic conditions, wet, normal, and dry.
Physically available flows and the location of the estimated flows are presented on Figure 7-1.
Green River Basin
Table 7-2 indicates that there is significant physically available flow in the Green and Little
Snake Rivers. Figure 7-2 shows the locations where flows were determined to physically exist for the
Green River. Figure 7-3 shows the flows and their locations for the Little Snake River. During the Green
River Basin study, estimates of legally available flow were not prepared.
Northeast Wyoming River Basins
Physically available flow estimates and the location of the flow estimates are displayed on Figure
7-4. Table 7-2 indicates that there is very limited legally available surface water in the Northeast
Wyoming River Basin planning area. During the Northeast Wyoming study, estimates for legally
available flows were prepared for only the Belle Fourche River and Redwater Creek. No flow estimates
were prepared for the Little Missouri River and Niobrara River.
Platte River Basin
Flow estimates were not made for the Platte River Basin during the river basin planning effort.
Hydrologic information was provided through the Nebraska v Wyoming lawsuit. In the framework
planning effort, North Platte River flows were estimated for the three hydrologic conditions, wet, normal,
and dry, based on USGS gaged flow data. The Platte River system is fully appropriated. In the Platte
River system, there is very limited legally available surface water in the planning area under normal
conditions. A water supply based on a current-day water right filing would be in priority and able to be
utilized only during extremely wet hydrologic conditions due to water rights administration and therefore
would be of little value.
Powder/Tongue River Basin
Physically available flow estimates and the location of the estimated flows are displayed on
Figure 7-5. Table 7-2 indicates that there is considerable legally available flow in the Powder River and
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Tongue River. During the Powder/Tongue Rivers Basin study, estimates of the legally available flows in
the Little Powder River and the Little Bighorn River were not made. Legally available flows may exist in
those drainages.
Snake/Salt Rives Basin
Physically available flow estimates and the location of the estimated flows are shown on Figure
7-6. During the Snake/Salt Rivers Basin study, no estimates of flows were made for the Teton and
Henrys Fork Rivers. Physically available flows and legally available flows may exist in those drainages.
Wind/Bighorn River Basin
Flow estimates were prepared for the three hydrologic conditions, wet, normal and dry. The
physically available flow estimates and the location of the estimated flows are presented on Figure 7-7.
Table 7-2 shows that the Wind/Bighorn and Clarks Fork Rivers are among the most hydrologically
prolific rivers in Wyoming. During the Wind/Bighorn River Basin study, model runs were made for
conditions with the Tribal Futures Projects developed as well as without the development of the Tribal
Futures Projects. These two scenarios do not affect the legally available flows as there is a decreed
amount of water associated with the Tribal Futures Projects. In Table 7-2, the legally available flows
shown for the Upper Wind, Little Wind, and Lower Wind Rivers include the Tribal Futures decreed water
right. A more detailed discussion of this situation is contained in the Wind/Bighorn River Basin Plan
final report and the associated technical memorandum.
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Table 7-2 Available Flows
Hydrologic Condition
Wet Normal Dry
Physically
Available Flow
Legally
Available Flow
Physically
Available Flow
Legally
Available Flow
Physically
Available Flow
Legally
Available Flow
Basin
ac-ft per year
Bear River
Upper Division 360,000 325,000 176,000 142,000 37,000 27,000
Central Division 786,000 508,000 427,000 188,000 132,000 0
Green River
Henrys Fork 125,000 NA 60,000 NA 23,000 NA
Lower Blacks Fork 422,000 NA 229,000 NA 101,000 NA
Lower Hams Fork 186,000 NA 95,000 NA 48,000 NA
Upper Blacks Fork 247,000 NA 136,000 NA 54,000 NA
Upper Little Snake River 311,000 NA 211,000 NA 111,000 NA
Lower Little Snake River 665,000 NA 449,000 NA 189,000 NA
Lower Green River 1,924,000 NA 1,269,000 NA 620,000 NA
Above Fontenelle Reservoir 1,659,000 NA 1,073,000 NA 496,000 NA
Upper Green River 701,000 NA 464,000 NA 251,000 NA
New Fork River 776,000 NA 573,000 NA 301,000 NA
Horn Creek 93,000 NA 57,000 NA 24,000 NA
Cottonwood Creek 97,000 NA 50,000 NA 15,000 NA
West Fork New Fork 183,000 NA 122,000 NA 57,000 NA
Pole Creek 404,000 NA 282,000 NA 146,000 NA
East Fork New Fork 211,000 NA 119,000 NA 56,000 NA
Piney Creek 76,000 NA 42,000 NA 18,000 NA
Northeast Wyoming
Upper Belle Fourche 14,000 NA 4,000 NA 200 NA
Middle Belle Fourche 9,000 NA 3,500 NA 400 NA
Lower Belle Fourche 151,000 15,600 71,000 7,400 13,000 1,100
Redwater Creek 34,000 3,300 26,000 2,400 17,000 1,400
Upper Beaver Creek 11,000 NA 9,000 NA 5,000 NA
Middle Beaver Creek 17,000 NA 14,000 NA 9,000 NA
Lower Beaver Creek 30,000 NA 20,000 NA 14,000 NA
Northern Tribs to Cheyenne River 58,000 NA 13,000 NA 2,000 NA
Southern Tribs to Cheyenne River 45,000 NA 18,000 NA 3,000 NA
Lower Cheyenne River 103,000 NA 31,000 NA 5,000 NA
Little Missouri River NA NA NA NA NA NA
Niobrara River NA NA NA NA NA NA
Powder/Tongue River
Little Bighorn 152,000 NA 113,000 NA 81,000 NA
Tongue River 473,000 163,000 326,000 90,000 218,000 40,000
Upper Clear Creek 213,000 NA 124,000 NA 80,000 NA
Lower Clear Creek (Powder River) 547,000 211,500 324,000 131,000 194,000 74,300
Upper Crazy Woman Creek 49,000 NA 22,000 NA 6,000 NA
Lower Crazy Woman Creek 61,000 NA 31,000 NA 16,000 NA
Upper Powder River 230,000 NA 153,000 NA 91,000 NA
South Fork Powder River 44,000 NA 27,000 NA 13,000 NA
Lower Powder River 328,000 NA 195,000 NA 111,000 NA
Little Powder River 48,000 NA 12,000 NA 3,000 NA
Snake/Salt River
Salt River 694,000 31,000 458,000 22,000 216,000 12,000
Snake River 4,159,000 165,000 2,888,000 116,000 1,769,000 69,000
Teton River NA NA NA NA NA NA
Henrys Fork NA NA NA NA NA NA
Wind/Bighorn River
Clarks Fork 1,144,000 686,000 740,000 444,000 499,000 299,000
Upper Wind River 1 471,000 355,000 250,000 150,000 75,000 70,000
Little Wind River 1 137,000 137,000 88,000 88,000 27,000 27,000
Lower Wind River 1 987,000 878,000 749,000 684,000 332,000 293,000
Upper Bighorn River 1,695,000 NA 1,303,000 NA 871,000 NA
Owl Creek 48,000 NA 28,000 NA 9,000 NA
Nowood River 425,000 NA 296,000 NA 249,000 NA
Lower Bighorn River 1,912,000 NA 1,568,000 NA 920,000 NA
Greybull River NA NA 108,000 NA 48,000 NA
Shoshone River 1,082,000 NA 748,000 NA 472,000 NA
Bull Lake Creek 162,000 112,000 108,000 71,000 14,000 14,000
Dinwoody Creek 64,000 57,000 40,000 37,000 6,000 6,000
Middle Fork Popo Agie River 166,000 166,000 108,000 108,000 61,000 61,000
North Fork Little Wind River 95,000 95,000 63,000 63,000 12,000 12,000
Shell Creek 57,000 NA 47,000 NA 19,000 NA
Note: NA - Information was not presented in the individual basin plans.
1 Legally available flows include the development of the Tribal Futures Projects.
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7.1.6 Future Supply Estimates
The most conservative estimate of water availability is the dry hydrologic condition depleted by
the projected uses discussed in Chapter 6. In the river basin plans, the most likely projection scenario is
the moderate or Mid Scenario. Table 7-3 shows the flow estimates resulting from the mid-level
depletions and the dry hydrologic condition.
Table 7-3 Average Annual Streamflow and Uses - Mid-Level Development - Dry Condition
Future Depletions of Streamflow to Wyoming
Basin
GREAT BASIN
State Line
Depleted
Outflow -
Municipal,
Streamflow
Natural
Domestic,
Reservoir
Leaving
Conditions 1 Irrigation 2 & Stock 2 Industrial 2 Evaporation 2 Total 2 Wyoming 3
ac-ft
Wyoming's
Remaining
Share
Under
Compact
Bear River 235,200 94,500 3,400 0 5,300 103,200 132,000 0
COLORADO RIVER
Green River 4 1,614,500 423,000 30,800 106,400 121,300 681,500 933,000 150,200
MISSOURI RIVER
Northeast Wyoming 5 145,300 72,800 0 0 23,500 96,300 49,000 2,500
Platte River 6 1,110,800 484,600 27,100 61,300 213,800 786,800 324,000 0
Powder/Tongue
River 733,300 194,000 15,000 17,000 11,300 237,300 496,000 248,100
Wind/Bighorn River 3,686,100 1,305,700 18,000 38,700 138,700 1,501,100 2,185,000 1,648,000
Yellowstone River 7 2,374,000 2,374,000 0
COLUMBIA RIVER
Snake/Salt River 8 2,164,300 107,100 0 0 72,200 179,300 1,985,000 90,000
Total 12,063,500 2,681,700 94,300 223,400 586,100 3,585,500 8,478,000 2,138,800
1 Estimates are based on outflow plus depletions from the current river basin plans.
2 Depletion estimates are from the current river basin plans.
3 Depleted flows are based on outflow estimates from the current river basin plans.
4
Depletions for municipal, domestic, and stock include 22,700 acre-feet per year diverted to the N. Platte for
City of Cheyenne use.
5 Excludes the flows for the Little Missouri and Niobrara Rivers.
6 The Platte River system is fully appropriated in that a water supply that is based on a water right with a current day priority cannot be expected to provide a
reliable supply due to water rights administation. Estimates exclude the flows and depletions from the Horse Creek and South Platte drainages.
7 Drainage area is within Yellowstone National Park and includes estimates for the Madison, Gibbon, Firehole, and Gallatin Rivers.
8
Excludes the flows for the Henrys Fork and Teton Rivers.
Under the dry hydrologic condition, in the Bear River Basin, Northeast Wyoming River Basin,
and the Platte River Basin, there is little if any legally available surface water.
7.2 GROUNDWATER
7.2.1 Background
The availability of groundwater is a function of the physical characteristics of the aquifer at the
location of interest (see Chapter 4) and the value of the intended use. For example, an industrial use may
be able to afford to drill deep wells, sustain large drawdowns, and treat groundwater of undesirable
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7.0 AVAILABILITY
quality, whereas an irrigation use may be economical only where wells are shallow, production is high,
and quality is adequate without treatment. Virtually any of the “major” aquifers described in Chapter 4
could provide useful groundwater supplies, given sufficient development value. The “minor” and
“marginal” aquifers could provide modest supplies of good-quality groundwater at many locations.
Successful groundwater development in the “major aquicludes” group will be dependent upon locally
favorable conditions and minimal quantity and quality demands.
Development of groundwater in sufficient quantities and of sufficient quality to meet specific
project goals will require site-specific hydrogeologic analyses. None of the aquifers discussed in Chapter
4 are universally productive; none are entirely free of water quality concerns. While the generalizations
of this report can provide guidance on the location and potential of various aquifers, local evaluation
programs are essential to development success.
The relationship between the groundwater and surface water portions of the overall water
resource depends upon the location, depth, rate, volume, and use of the groundwater withdrawn, all in the
context of the local and regional hydrogeologic environment. When a well is initially pumped,
groundwater is removed from storage to create a cone of depression. That cone will grow deeper and
broader as pumping continues until a balance is established between pumping from the aquifer and inflow
to the aquifer from 1) adjacent water-bearing rocks and/or 2) surface water sources. The latter may
include stream infiltration induced by pumping, interception of groundwater flow that would otherwise
continue towards discharge at the surface, or production of groundwater that would otherwise be taken up
and transpired by plants (a capture process known as “ET salvage”).
7.2.2 Diversion Rates
In general, groundwater diversion rates of less than 5 gpm are widely, although not universally,
available throughout Wyoming. Diversion rates in the 5 to 50 gpm range are likely obtainable from most
of the areas of “major aquifers” shown on Figure 4-9. Diversion rates in excess of 50 gpm may require
favorable local conditions of permeability. Rates on the order of 1,000 gpm are only routinely available
from certain areas of productive alluvium (e.g., the Snake River plain) and from well-recharged and
fractured occurrences of the major bedrock limestone aquifers. These assessments apply to instantaneous
diversion rates, however, and may or may not represent the conditions necessary to sustain those rates
over extended periods, when subject to the cumulative impacts of multiple wells, or when stream
depletion is an issue.
7.2.3 Groundwater in Storage
The depth to the groundwater table is rarely more than a few hundred feet. Beneath that, water is
stored in the pore space of the rocks to a depth where porosity falls effectively to zero, e.g., in the
crystalline rocks known as “basement”. In Wyoming’s deepest basins, sedimentary rocks – sandstone,
shale, limestone, etc. – extend to depths of 30,000 feet. Thus, there is a vast amount of groundwater in
storage, although much of it is too expensive to develop – due to unfavorable permeability, depth, or
quality – to represent a useful resource. Not surprisingly, calculations of the total volume of groundwater
in storage generate impressively large values. For example, the 1973 Framework Water Plan estimated
total bedrock-aquifer storage for the state of 3.1 billion acre-feet 1 .
1 Based on estimates that 10 percent of the total volume of sediments in each basin is “aquifer material” and 5 percent of that material is groundwater.
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Calculations of groundwater storage in alluvial aquifers are somewhat more meaningful, as much
of this water is reasonably assessable. The 1973 Framework Plan estimated alluvial aquifer storage for
the state at 10.2 million acre-feet. Neither this nor the estimate of bedrock groundwater storage has been
updated.
Groundwater in storage can be viewed as 1) a surface reservoir, from which water can be
extracted repeatedly as it is subsequently refilled, or 2) a groundwater “mine”, from which water can be
extracted one time. The alluvial aquifer is most akin to a surface reservoir. It is filled either by
streamflow infiltration or groundwater recharge that would otherwise proceed into the stream. Use of
aquifer storage reduces streamflow, and that reduction continues until the reservoir is refilled. Where
quantities of water in excess of contemporaneous streamflow are needed seasonally, the groundwater
reservoir can be exercised to better align demands with supply by “evening out” surpluses and deficits.
This process happens naturally across many of Wyoming’s irrigated lands, as large springtime diversions
generate return flows that sustain late-season streamflows.
Similarly, artificial aquifer storage and recovery (ASR) projects can be developed to deliberately
recharge and draft groundwater reservoirs. Permitting requirements and land-use conflicts can be
substantially less for groundwater reservoir projects than for surface reservoirs, evaporation losses are
less, and water-treatment issues may be avoided. Although such projects are currently uncommon in
Wyoming, there have been several studies of ASR in the Cheyenne area, and Laramie is currently
investigating ASR as a technique for banking excess groundwater for later use.
More like a groundwater “mine” are aquifers for which surface connection is measured on the
scale of decades or centuries. While this groundwater, too, will ultimately be replaced from surface
sources, that replacement may be so diffuse and over such a long time period that it is effectively a
nonrenewable resource. For example, a study of the Splitrock Aquifer south of the Sweetwater River
currently being completed by the WWDC concludes that 200,000 acre-feet of groundwater can be
removed over a 40-year period without meeting the Modified North Platte Decree criteria for
“hydrological connection” 2 .
At present, no statewide criteria have been promulgated for assessment of the interaction of
groundwater with surface water 3 , nor have estimates been developed of groundwater storage volumes
available under “not connected” status. In general, the deeper and more distant from surface water
features the groundwater is, the less is the likelihood of significant surface water connection.
The removal of groundwater from storage is indicated by a lowering of the groundwater table (or,
in the case of a confined aquifer, by a decrease in pressure). Bedrock aquifers are generally deeper and
more distant from streams than are alluvial aquifers and are more likely to experience groundwater level
declines before production rates and recharge rates come into balance. Short-term fluctuations in
groundwater levels may reflect seasonal variations in recharge and discharge, multi-season climate cycles,
or deliberate drafting and recovery management. Long-term changes in groundwater levels indicate a
deficit (or, in some cases, a surplus) of recharge relative to production. As groundwater-levels decline,
users of the aquifer may experience difficulty in obtaining historical quantities of groundwater, and
conflicts may develop.
Reports of groundwater level declines and conflicts are concentrated in the Platte and Powder
2 The Modified North Platte Decree was negotiated to define “hydrological connection” as a stream depletion volume of 28 percent or more of the volume
pumped over 40 years.
3 In other states, criteria of 10 percent in 50 years, 1 percent in 100 years, etc. are used to regulate aquifer stream interactions.
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River Basins. The Platte is home to all three of Wyoming’s Groundwater Control Areas – Prairie Center,
Platte County, and Laramie County – each precipitated by declining groundwater levels. See Figure 7-8.
It has also been the basin of groundwater interference complaints/investigations near Saratoga, Bates
Creek, Glenrock, Horseshoe Creek, Cottonwood Creek, Hawk Springs, and Laramie.
In the Powder River Basin, concerns with groundwater level declines are centered on the coalbed
methane (CBM) industry. CBM production is inherently in conflict with groundwater levels as it depends
on substantial drawdown to release the methane gas from the coal seams. For the same reason, CBM
development cannot occur where permeabilities are high, so it is an industry focused on areas where
groundwater supplies are not abundant to begin with. Short-term drawdowns in the Wasatch aquifer are
projected by the BLM EIS to be 500-800 feet over much of the basin. Recovered water levels following
CBM exhaustion are projected to remain 30 feet below original levels.
As CBM production spreads to other basins, it will target coal seams in the “sandstone” aquifers
shown on Figure 4-9. Impacts to existing groundwater users in these areas remain to be seen. Because
the coal seams are generally deeper than in the Powder River Basin, conflicts with existing users are
likely to be less.
No significant areas of groundwater decline are reported for the Bear, Snake/Salt, or Green River
Basins. In the Wind/Bighorn Basin, groundwater levels have dropped as a result of municipal and
irrigation withdrawals in the Riverton and Hyattville areas, respectively.
7.2.4 Groundwater Recharge
A common approach to estimating the quantity of groundwater available for continuous
development, as opposed to one-time extraction, is to estimate groundwater recharge. If no more water is
taken from the groundwater reservoir than flows into the reservoir, no long-term decline will occur. Total
groundwater recharge was estimated in several of the basin plans:
! 2 million ac-ft/yr for the Platte River Basin, based on recharge equal to 10 percent of
precipitation.
! 50,000 ac-ft/yr for the Green River Basin, based on recharge equal to 10 percent of precipitation,
but only for those areas where precipitation exceeds potential evapotranspiration.
! 1 million ac-ft/yr for the Snake/Salt River Basin, based on detailed estimates of recharge rates
from the University of Wyoming groundwater vulnerability study (Wyoming Water Resources
Center, 1998).
! 14,000 ac-ft/yr for the Bear River Basin, based on recharge equal to 2 percent of precipitation.
There is little consensus on detailed estimation of groundwater recharge rates, which are a
complex function of the seasonal timing, duration, intensity, and type of precipitation; the infiltration
characteristics of the soil; the hydraulic properties of the uppermost geologic materials; and the manner in
which groundwater recharge moves within and between aquifers. Groundwater recharge is the source of
“base flow” to streams. While matching groundwater consumption to recharge would prevent widespread
groundwater level declines, it would also lead to dry streambeds for much of the year.
Where groundwater is closely connected with surface water, as in much of the alluvial aquifers,
the locations and long-term availability of groundwater are effectively the same as for surface water.
There may still be good reasons to develop groundwater. A municipality, for example, may choose to
divert groundwater rather than the same quantity surface water, despite a depletive connection, to capture
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the substantial benefits of more stable chemistry, much reduced treatment requirements, higher winter
temperatures, etc. Similarly, a decision on development of additional water supplies as groundwater or
surface water may depend on the availability of project funding, which may vary by water source. Where
surface flows are adequate to meet demands on average, but may be seasonally inadequate or may be
compromised by short-term drought cycles, use of the alluvial groundwater reservoir may be useful to
modulate variations in the availability of surface water resources over time.
The most abundant supply of undeveloped alluvial groundwater appears to be in the Snake/Salt
Basin, particularly in the Snake River Aquifer in Teton County. Given the abundance of available surface
water in that basin, conflicts with surface water are not expected to be a major constraint on groundwater
development. In the Platte Basin, in contrast, surface water connection is addressed by the Modified
North Platte Decree and the recently finalized Platte River Recovery Implementation Program (PRRIP),
and presents a major limitation on future development. Maps have been developed of those portions of
the Platte River Basin that, upon initial investigation, appear to produce depletions less than the
“hydrologically connected’ criteria. In areas more closely associated with stream depletions, major
additional development of groundwater in the Platte Basin is likely to come primarily through trade or
replacement arrangements with respect to surface water.
In summary, the above approaches to estimate the amount of groundwater in storage and the total
recharge to groundwater provide upper bounds on the possible supplies of mineable groundwater and
sustainable groundwater production, respectively. As a practical matter, however, the available
groundwater supply is substantially less.
7.2.5 Groundwater Quality
Most water uses have some sensitivity to water quality. Thus,
groundwater availability also will be a function of how the quality from a
particular aquifer and location aligns with the needs of a particular use.
As explained in Chapter 4, natural groundwater quality is generally best
closest to outcrop and deteriorates the longer groundwater has been in
contact with aquifer minerals. This effect is weakest in the “major
aquifers” of Figure 4-9 and strongest in the “minor” and “marginal”
aquifers.
For the most part, Wyoming has been relatively free of
widespread human impacts to groundwater quality. Beyond conflicts
associated with relatively high concentrations of nitrates in water supply
wells around Torrington, generally understood to result from application
of crop fertilizer, groundwater contamination issues in Wyoming have
largely been confined to local incidents of spills and leaks. These
incidents have compromised the availability of groundwater in local areas
but rarely have had widespread effects.
As discussed in Chapter 4, certain Wyoming aquifers are more susceptible to contamination than
others. The alluvial aquifers are generally the most productive, but due to their relatively high
permeabilities, exposure at the surface, and location along developed stream corridors, they are more
subject to water quality impacts from surface uses.
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7.2.6 Basin Summaries
Table 7-4 summarizes the general groundwater availability conclusions of the individual river
basin plans. Only the “major” aquifers are addressed in Table 7-4.
Table 7-4 Groundwater Availability Summary
Bear River Basin
Alluvial Aquifers
Aquifer (Group)
Snake/Salt River Basin
Alluvial Aquifers
Aquifer (Group)
Local development potential, with surface water depletion
Other Aquifers
Highly localized potential for high yields and quality, depending on
local geologic conditions; stream depletion concerns may apply
Green River Basin
Alluvial Aquifers
Local development potential, with surface water depletion
Major Aquifers - Sandstones
Coalbed methane production may provide groundwater
Northeast Wyoming and Powder River Basin
Madison Formation (Major Aquifers - Limestone)
Total recharge estimated at 75,000 ac-ft/yr
Potential well yields up to >1,000 gpm
Accessible depths around Black Hills
Water quality likely deterioriates with depth
Lance/Fox Hills (Major Aquifers - Sandstones)
Low to moderate yields
Potential high-fluoride issues
Fort Union / Wasatch Formations (Major Aquifers - Sandstones)
Coalbed methane groundwater production provides use
opportunities and water level impacts
Alluvial Aquifers
Local development potential, with surface water depletion
Platte River Basin
Alluvial Aquifers
Development potential only with recognition of surface depletion
Ogalalla and Arikaree Formations (Major Aquifers - Sandstones)
Additional development potential in South Platte drainage, subject
to Control Area limitations
North Platte development potential mainly in areas deemed "not
hydrologically connected"
Casper Formation (Major Aquifers - Limestone)
Production highly dependent on local geologic conditions
Accessible depths along north and east slopes of Laramie Range
North Platte development potential mainly in areas deemed "not
hydrologically connected"
Yields up to 1,000 gpm potentially available, with surface water
depletion
Highest availability along Snake River
Potential quality concerns with proliferation of septic systems
Salt Lake Formation (Major Aquifers - Sandstones)
High-yield wells highly dependent upon local geologic conditions
Other Aquifers
Highly localized potential for high yields and quality, depending on
local geologic conditions
Wind/Bighorn River Basin
Alluvial Aquifers
Well yields 10 - 500 gpm
Surface water depletion issues
Wind River Formation (Major Aquifers - Sandstones)
Already heavily developed in some areas
Potential for high-capacity wells elsewhere
Groundwater quality variations may constrain use
Madison Formation (Major Aquifers - Limestone)
Potential for >1,000 gpm flowing wells
Production highly dependent on local geologic conditions
Accessible depths along west slope of Bighorn Mountains,
northeast slopes of Wind River Mountains
Flathead Formation (mapped with Major Aquifers - Limestone)
Yield potential for >1000 gpm flowing wells highly dependent upon
local geologic conditions
Accessible depths along west slope of Bighorn Mountains
In general, groundwater availability is greatest for the alluvial aquifers of the state, with the
understanding that connections with surface water will have to be addressed. The “major aquifers -
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limestone” group has potential for development of high-yield, perhaps flowing, wells adjacent to most
Wyoming mountain ranges, but these aquifers are highly dependent upon local geologic conditions to
produce favorable conditions.
Table 7-5 shows SEO groundwater permits by type of use by river basin for the state. In addition,
the table shows the 10-year growth rates of permit applications.
Table 7-5 Groundwater Permits Summary
Irrigation
Rural Drinking
Water Municipal Industrial CBM
River Basin
Total
Permits
10-Yr
Growth
Total
Permits
10-Yr
Growth
Total
Permits
10-Yr
Growth
Total
Permits
10-Yr
Growth
Total
Permits
10-Yr
Growth
Bear 59 4.0% 1,037 2.6% 8 4.8% 18 0.0% 0 0.0%
Green 90 2.3% 7,193 3.9% 34 1.6% 262 1.9% 798 53.5%
Northeast 289 0.9% 9,779 2.4% 109 2.9% 558 2.6% 9,446 45.3%
Platte 2,022 1.1% 29,320 2.8% 278 0.9% 362 1.8% 81
Powder/Tongue 177 2.5% 9,829 3.6% 15 1.4% 282 1.4% 22,490 81.8%
Snake/Salt 86 2.7% 4,919 4.5% 23 2.5% 10 1.1% 0 0.0%
Wind/Bighorn 238 4.3% 16,132 2.5% 98 1.3% 314 0.4% 16
Total 2,961 1.5% 78,209 3.0% 565 1.5% 1,806 1.7% 32,831 60.3%
Note: All wells with zero yields excluded; wells with "unknown" yields or no yield data included.
A more detailed discussion of the groundwater situation in the individual river basin planning
areas is contained in the individual river basin plans and associated technical memoranda.
7.3 WATER CONSERVATION
7.3.1 Introduction
In general, the state has adequate water to serve the needs of its river basin residents. For the
most part, water shortages are seasonal, and their effects can be magnified by drought conditions. Water
conservation is any beneficial reduction in water losses, waste, or use.
Agricultural water consumption is the major water use sector in Wyoming. The Irrigation
Association, an international organization that was started in 1949 and states that it is dedicated to
“promoting water and soil conservation through proper water management,” takes the following positions
regarding long-range water conservation planning:
! Measure all water use.
! Price water so as to recognize its finite nature, provide financial incentives to users who
conserve water, and provide financial penalties to users who waste water.
! Hold all water users responsible for protecting the quality of the water that they use.
! Create financial systems to reward users of efficient irrigation systems.
! Create national education programs regarding the “absolute necessity of supporting
regulatory policies which reward conservation and efficient water use”.
! Support water reclamation and reuse initiatives, particularly for irrigation, but also for
municipal, industrial, and other water uses sectors.
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! Increase support for developing new water sources, including new conveyance and storage
systems and incorporating into development plans appropriate environmental concerns.
! Maintain water conservation planning as an ongoing program.
! Promote policies which allow for the lease, sale, or transfer of “established water rights”
and/or the lease, sale, and transfer of water without jeopardizing established water rights,
whenever possible. (Irrigation Association, 2005)
Water conservation in Wyoming involves all uses including agriculture, municipalities, industry,
recreation, and environmental concerns. In the past, water conservation efforts were mainly focused on
improving efficiency of agricultural water use. As communities within the state have grown and changed,
there is a growing interest in flat water activities and streamflow-related recreation. Water conservation
has different meaning at different times of the year and to different water users. Given Wyoming’s
climate and topography, storage of spring runoff must be included in consideration of water conservation
for any water use sector (Tyrrell, 2004). The following is a discussion of water conservation activities
and opportunities.
7.3.2 Agricultural Water Conservation
The largest water savings by quantity are generally
realized by conservation in the agricultural sector, as it
represents the largest use of water in the state. For this
reason, much of the focus of water conservation is on
irrigation practices. In order to determine what future
conservation efforts will be effective, an inventory of
existing facilities is necessary. Major items of interest in
this inventory include conveyance facilities and irrigation
methods.
A significant portion of water diverted for irrigation
can be lost during conveyance to the field through seepage, deep percolation, phreatophytes, evaporation,
and so forth. Water is typically diverted from the river or stream into a canal or ditch, which is generally
of earth construction and unlined. The soils in many of the river basin valleys are predominantly gravelly
loams as they were formed on the alluvium of the many rivers, streams, and washes that are present in the
valleys. Water will quickly percolate through these granular soils. No extensive studies have evaluated
ditch conveyance losses across the state.
The USBR and WWDC have worked on joint funded projects where the open canal and lateral
system has been replaced with an enclosed gravity pressurized sprinkler system. The Sand Mesa project
on the Midvale Irrigation District is an example.
Membrane liners have been used with good results on some of the large USBR canals around the
state. Research has indicated that application of polyacrylamide (PAM) to the canal bottom and sides will
reduce seepage losses and increase transmission efficiencies.
Irrigation methods also present an opportunity for water conservation. In Wyoming, historically
flood irrigation was the most popular method used and still is very popular in spite of its low efficiency.
Efficiency of flood irrigation has improved through the use of gated pipe and surge valves. Use of this
technology has reduced water loss to seepage in laterals and to deep percolation that is not available to the
crops.
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Since the early 1970s many areas in Wyoming have converted to sprinkler irrigation. Utilization
of hand lines or wheel lines has been replaced by use of center pivot systems. Sprinkler design and
efficiency have also increased over time with the use of low energy consuming or low pressure
application systems. For the most part, the conversion from flood to sprinkler irrigation has had a
positive effect, as crop yields have increased considerably. Also, more acres of cropland can be irrigated
late in the summer when there is less water available. However, some positive aspects of flood irrigation
have been reduced with the conversion to sprinkler irrigation, such as groundwater recharge, reduction of
peak runoff, and enhanced late season flow due to late season irrigation return flows.
7.3.3 Industrial Water Conservation
Industrial water use is very important as industry employs a significant percent of the state’s work
force and generates a large portion of the state’s payroll. Conservation by industry differs by industrial
sector.
In the case of cooling water, a means of conserving water is dry cooling. As with many of the
other conservation measures, dry cooling comes at a cost both in construction and efficiency. In some
sectors, reuse of water may be a conservation measure.
The other major industrial water use category is for process water. Conservation in an industrial
process may be tied to major redesign of the particular industrial or manufacturing process. These
changes are industrial sector-specific as well as individual plant-specific.
7.3.4 Municipal Water Conservation
Municipal water use is a significant use of water in the state following agricultural and industrial
water use. Water conservation measures have been implemented by some of the municipalities in
Wyoming; however, it has not been a major focus in all areas of the state.
Conservation measures generally consist of individual customer meters that track actual water
use. Meters can also help determine if there are major losses in the distribution system through leaks.
Many municipalities meter their public water systems, but some systems do not and have little or no
incentive to conserve water. The expense of installing meters can be seen as prohibitive, and is unpopular
politically. Also, some systems encourage water use during the winter months to prevent frozen pipes.
Some systems are requiring meters on new hookups and considering phasing in metering for the existing
population.
7.3.5 Recreational and Environmental Water Conservation
A growing amount of water use in the state is related to recreational and environmental uses.
While these are generally nonconsumptive uses, water is still key to many of these activities. Various
wetland and riparian enhancement projects have been conducted throughout the state over the years.
While these projects do not necessarily conserve water, they do conserve or enhance habitat for fish,
waterfowl, and other animals. Water utilized for wetlands may also be considered conservation of bird or
fish habitat, although more water is used than if the wetland was not maintained. Also, the USBR has
agreed to maintenance flows at some USBR dams in order to provide sufficient flow for fish during the
winter months or other periods of aquatic concern.
Water storage can serve an important role in meeting these water needs by providing increased
management of the available water supply for these uses. Storage can also serve to conserve water by
meeting the needs of the resource while holding over surplus water for later use.
7-17

7.0 AVAILABILITY
Fencing to keep cattle off of a stream bank can help reduce erosion, improve water quality, and
maintain habitat. In these circumstances, an off-stream location for stock watering must be developed.
7.3.6 Conclusion
In order for conservation methods to be successfully implemented, there must often be an
incentive or benefit for those involved. This incentive may be in various forms, such as increased crop
yields, improved fishing, reduced costs, and so forth.
Reduction of conveyance losses and improvement of irrigation efficiency do not necessarily
equate to less water used. In areas of deficit, conservation measures may result in the conserved water
being applied to additional acres or providing a full supply of water throughout the season without a
decrease in the water diverted. However, this improvement in efficiency will likely result in an increase
in the crop quality and yield.
Prior to implementation of conservation improvements, the situation should be studied to see how
conservation is addressing the issue and to make sure that the program will have the intended result.
Under the prior appropriation doctrine, water left in the stream is available to other users, and
there is presently no mechanism whereby a diverter can capitalize on investment in conserving measures
where the saving remains in the stream for use by other interests.
Water saved or water yield from conservation was not estimated in the river basin planning area
studies. The amount of saved water or water yield, from conservation measures, is site-specific, and as
was noted above, conservation measures may actually result in more water use rather than less.
7.4 REFERENCES
Irrigation Association, The. 2005. Drought: A Handbook for Prevention and Action.
http://www.irrigation.org.
Tyrrell, P., Wyoming State Engineer. 2004. Water Conservation and Wyoming Law:
What Are Our Current Constraints? In Proceedings of the Wyoming Water Association 2004
Annual Educational Seminar and Meeting. October 27-29, 2004. Casper, WY.
Wyoming Water Development Commission. 2001. Guidelines for Development of Basin
Plans.
Wyoming Water Resources Center. University of Wyoming. 1998. Wyoming
Groundwater Vulnerability Assessment Handbook.
7-18

THAYNE
Note: The Physically Available Flow estimates are for a specific
location and are not additive with other availability estimates.
In other words, if a project were constructed that depleted
water at a given location, availability at this and other
locations in the basin would be reduced.
PINEDALE
AFTON
Central
Division
SUBLETTE
ID A H O
Dry: 132K
Normal: 427K
Wet: 786K
#*
Thomas Fork
Bear River
Smiths Fork
Smiths Fork
LINCOLN
LA BARGE
COKEVILLE
Dry: 37K
Normal: 176K
Wet: 360K
#*
Bear River
Twin Creek
KEMMERER
OPAL
Dry: 80K
Normal: 190K
Wet: 370K
GRANGER
SWEETWATER
#*
GREEN RIVER
Bear River
Yellow Creek
EVANSTON
Upper
Division
UINTA
LYMAN
MOUNTAIN VIEW
#*
Dry: 77K
Normal: 168K
Wet: 315K
U T A H
#
Dry: 0K
Normal: 50K
Wet: 100K
LEGEND
Available Flow Marker
Physically Available Flow,
thousand ac-ft
7-19
"
Figure 7-1
Bear River Basin
Physically Available Flows

I D A H O
JACKSON
Note: The Physically Available Flow
estimates are for TETON a specific location
and are not additive with other
availability estimates. In other
words, if a project were constructed
that depleted water at a given location,
ALPINE
availability at this and other locations
in the basin would be reduced.
#*
Dry: 219K
Normal: 355K
Wet: 494K
PAVILLION
THAYNE
SUBLETTE
PINEDALE
Dry: 134K
Normal: 260K
Wet: 360K
FREMONT
LANDER
HUDSON
AFTON
Cottonwood Creek
#* #*
Dry: 146K
Normal: 282K
Wet: 404K
Dry: 251K
Normal: 464K
Wet: 701K
#*
Dry: 56K
Normal: 119K
Wet: 211K
LINCOLN
La Barge Creek
BIG PINEY
LA BARGE
Dry: 496K
Normal: 1,073K
Wet: 1,659K
#* #*
#*
Dry: 301K
Normal: 573K
Wet: 776K
Dry: 57K
Normal: 122K
Wet: 183K
Little Sandy Creek
Pacific Creek
COKEVILLE
Fontenelle Creek
Slate Creek
Shute Creek
Shute Creek
KEMMERER
OPAL
Dry: 48K
Normal: 95K
Wet: 186K
SUPERIOR
SWEETWATER
EVANSTON
UINTA
Muddy Creek
Albert Creek
Dry: 11K
Normal: 18K
Wet: 33K
Dry: 23K
Normal: 52K
Wet: 102K
#*#*
Smiths Fork
UTA H
Muddy Creek
LYMAN
#*
#*
Dry: 18K
Normal: 33K
Wet: 56K
Dry Muddy Creek
MOUNTAIN VIEW
#* #*
Dry: 13K
Normal: 59K
Wet: 59K
#*
#*
#*
Dry: 54K
Normal: 136K
Wet: 247K
Dry: 28K
Normal: 59K
Wet: 116K
GRANGER
Dry: 10K
Normal: 51K
Wet: 51K
Dry: 101K
Normal: 229K
Wet: 422K
Big Dry Creek
Dry: 10K
Normal: 32K
Wet: 32K
#*
Dry: 620K
Normal: 1,269K
Wet: 1,924K
#*
Green River
GREEN RIVER
Dry: 23K
Normal: 60K
Wet: 123K
#*
ROCK SPRINGS
Vermillion Creek
COLORA DO
Shell Creek
#
Dry: 0K
Normal: 50K
Wet: 100K
LEGEND
Available Flow Marker
Physically Available Flow,
thousand ac-ft
7-20
"
Figure 7-2
Green River Basin, Upper Green
Physically Available Flows

Note: The Physically Available Flow
estimates are for a specific location
and are not additive with other
availability estimates. In other
words, if a project were constructed
that depleted water at a given location,
availability at this and other locations
in the basin would be reduced.
BAIROIL
SWEETWATER
RAWLINS SINCLAIR
HANNA
WAMSUTTER
CARBON
ELK MOUNTAIN
Dry: 32K
Normal: 69K
Wet: 94K
ENCAMPMENT
Mu dd y Cr
Dry: 189K
Normal: 449K
Wet: 665K
Little Sn a
e River
Dry: 41K
Normal: 89K
Wet: 121K
Savery Cr
Battle C
r
N. F or k Little Snake River
k
Dry: 149K
Normal: 338K
Wet: 486K
Dry: 30K
Normal: 66K
Wet: 89K
Dry: 111K
Normal: 211K
Wet: 311K
C O L O R A D O
#
Dry: 0K
Normal: 50K
Wet: 100K
LEGEND
Available Flow Marker
Physically Available Flow,
thousand ac-ft
"
7-21
Figure 7-3
Green River Basin, Little Snake River
Physically Available Flows

Dry: 0K
Normal: 50K
Wet: 100K
#
CAMPBELL
Mud Spring Creek
Upper Antelope Creek
GILLETTE
Cheyenne River
WRIGHT
Cabollo Creek
Hay Creek
Dry Fork Cheyenne River
Note: The Physically Available Flow
estimates are for a specific CONVERSE location
and are not additive with other
availability ROLLING estimates. HILLS In other
words, if GLENROCK a project were constructed
that depleted water at a given location,
availability at this and other locations DOUGLAS
in the basin would be reduced.
LEGEND
Available Flow Marker
Physically Available Flow,
thousand ac-ft
North Fork Little Missouri River
Prairie Creek
Dry: 0K
Normal: 4K
Wet: 14K
Black Thunder Creek
#* #* #* #*
Dry: 0K
Normal: 3K
Wet: 5K
Dry: 1K
Normal: 13K
Wet: 22K
Dry: 0K
Normal: 4K
Wet: 9K
MOORCROFT
Buffalo Creek
Walker Creek
Wind Creek
Dry: 1K
Normal: 3K
Wet: 21K
#*
Lightning Creek
Twentymile Creek
LOST SPRINGS
7-22
M O N T A N A
Little Missouri River
Arch Creek
#*
Belle Fourche River
Inyan Kara Creek
Lodgepole Creek
Upper Lance Creek
#*
CROOK
WESTON
"
Dry: 1K
Normal: 10K
Wet: 15K
UPTON
Dry: 4K
Normal: 36K
Wet: 69K
HULETT
MANVILLE
Upper Belle Fourche River
Upper Beaver Creek
#*
Lower Redwater Creek
SUNDANCE
Oil Creek
Cheyenne River
#*
#*
Lower Lance Creek
Niobrara River
Dry: 4K
Normal: 7K
Wet: 9K
#*
Old Woman Creek
Sand Creek
#*
#*
#* #*#*#*
Upper Redwater Creek
Lower Beaver Creek
Dry: 9K
Normal: 14K
Wet: 17K
Dry: 2K
Normal: 13K
Wet: 58K
NIOBRARA
LUSK
Dry: 3K
Normal: 14K
Wet: 36K
#*
#*
Bergreen Creek
#*
Dry: 5K
Normal: 9K
Wet: 11K
#*
Cheyenne River
Niobrara River
Dry: 1K
Normal: 2K
Wet: 4K
Dry: 4K
Normal: 4K
Wet: 6K
Dry: 4K
Normal: 5K
Wet: 8K
#*
Dry: 3K
Normal: 18K
Wet: 45K
Van Tassel Creek
Dry: 13K
Normal: 71K
Wet: 151K
Dry: 17K
Normal: 26K
Wet: 34K
Dry: 1K
Normal: 6K
Wet: 11K
Dry: 1K
Normal: 1K
Wet: 1K
N E B R A S K A
S O U T H D A K O T A
Dry: 14K
Normal: 20K
Wet: 30K
Dry: 5K
Normal: 31K
Wet: 103K
VAN TASSELL
Figure 7-4
Northeast River Basin
Physically Available Flows

Note: The Physically Available Flow
estimates are for a specific location
and are not additive with other
availability estimates. In other
words, if a project were constructed
that depleted water at a given location,
availability at this and other locations
in the basin would be reduced.
MANDERSON
WORLAND
Upper Little Bighorn River
BIG HORN
#* #*
WASHAKIE
HOT
SPRINGS
Dry: 9K
Normal: 12K
Wet: 16K
Dry: 81K
Normal: 113K
Wet: 152K
TEN SLEEP
Dry: 107K
Normal: 156K
Wet: 216K
Dry: 83K
Normal: 135K
Wet: 215K
j
Tongue River
DAYTON
Dry: 34K
Normal: 59K
Wet: 101K
#*
#*#*
Big Goose Creek
Dry: 218K
Normal: 326K
Wet: 473K
SHERIDAN
#*#*
Dry: 39K
Normal: 66K
Wet: 108K
Dry: 26K
Normal: 44K
Wet: 87K
Dry: 7K
Normal: 15K
Wet: 33K
#*#*
Dry: 2K
Normal: 9K
Wet: 22K
Powder
Dry: 18K
Normal: 27K
Wet: 34K
Praire Dog Creek
Dry: 24K
Normal: 43K
Wet: 69K
Piney Creek
#*
Rock Creek
#*#* #*
Badger Creek
#*
#* #*#*
Upper Clear Creek
Dry: 3K
Normal: 13K
Wet: 32K
Dry: 19K
Normal: 30K
Wet: 39K
Dry: 23K
Normal: 32K
Wet: 40K
Dry: 16K
Normal: 31K
Wet: 60K
Dry: 2K
Normal: 7K
Wet: 16K
-
#* #*
#*
#* #*
North Fork Powder River
Powder River
Dry: 41K
Normal: 58K
Wet: 102K
Dry: 28K
Normal: 41K
Wet: 48K
Murphy Creek
SHERIDAN
#*
Clear
#*
#*
Dry: 28K
Normal: 54K
Wet: 103K
Upper Crazy Women Creek
JOHNSON
KAYCEE
MO N T A N A
CLEARMONT
Dry: 24K
Normal: 48K
Wet: 100K
Lower Clear Creek
#*
Lower Salt Creek
Powder River
Powder River
#*
#*
Lower Crazy Women Creek
Dry: 6K
Normal: 22K
Wet: 49K
Dry: 8K
Normal: 13K
Wet: 19K
Dry: 13K
Normal: 27K
Wet: 44K
Dry: 80K
Normal: 124K
Wet: 213K
Dry: 74K
Normal: 120K
Wet: 209K
North Fork Powder River
#*
#*
Fortification Creek
Dry: 16K
Normal: 31K
Wet: 61K
Willow Creek
Dry Fork Powder River
Dry: 91K
Normal: 153K
Wet: 230K
#*
Spotted Horse Creek
Dry: 111K
Normal: 195K
Wet: 328K
Pumpkin Creek
Wild Horse Creek
Dead Horse Creek
Dry: 194K
Normal: 324K
Wet: 547K
Dry: 113K
Normal: 200K
Wet: 334K
Dry: 3K
Normal: 12K
Wet: 48K
Wildcat Creek
Little Powder River
Dry: 2K
Normal: 10K
Wet: 40K
Dry Creek
GILLETTE
#*
#*
CAMPBELL
WRIGHT
Dry: 3K
Normal: 12K
Wet: 48K
Spring Creek
#*
Cottonwood Creek
Indian Creek
MIDWEST
Castle Creek
Upper Salt Creek
#
Dry: 0K
Normal: 50K
Wet: 100K
FREMONT
LEGEND
Available Flow Marker
Wallace Creek
Physically Available Flow,
thousand ac-ft
NATRONA
7-23
CASPER
"
ROLLING HILLS
CONVERSE
Figure 7-5
Powder/Tongue River Basin
Physically Available Flows

M O N T A N A
Note: The Physically Available Flow
estimates are for a specific location
and are not additive with other
availability estimates. In other
words, if a project were constructed
that depleted water at a given location,
availability at this and other locations
in the basin would PARK be reduced.
Upper Falls River
Snake River
Snake River
TETON
Snake River
Buffalo Fork
Dry: 1,007K
Normal: 1,750K
Wet: 2,583K
Dry: 223K
Normal: 338K
Wet: 466K
JACKSON
DUBOIS
FREMONT
I D A H O
ALPINE
Dry: 216K
Normal: 458K
Wet: 694K
Greys River
Lower Hoback River
Dry: 1,769K
Normal: 2,888K
Wet: 4,159K
Upper Hoback River
Lower Salt River
Dry: 210K
Normal: 415K
Wet: 605K
PINEDALE
Upper Salt River
Salt River
AFTON
Dry: 25K
Normal: 44K
Wet: 72K
LINCOLN
MARBLETON
BIG PINEY
SUBLETTE
#
Dry: 0K
Normal: 50K
Wet: 100K
LEGEND
Available Flow Marker
Physically Available Flow,
thousand ac-ft
7-24
"
Figure 7-6
Snake/Salt River Basin
Physically Available Flows

Clarks Fork Yellowstone River-Bear Creek
MONT A N A
Note: The Physically Available Flow
estimates are for a specific location
and are not additive with other
availability estimates. In other
words, if a project were constructed
that depleted water at a given location,
availability at this and other locations
in the basin would be reduced.
Clarks Fork Yellowstone River
Lamar River
Upper Lamar River
Crandall Creek
Upper North Fork Shoshone River
Yellowstone River-Mountain Creek
Yellowstone River
Thorofare Creek
PARK
Sunlight Creek
Middle North Fork Shoshone Fork
Upper South Fork Shoshone River
Warm Spring Creek
#*
Clarks Fork Yellowstone River-Bennett Creek
Lower North Fork Shoshone River
Middle South Fork Shoshone River
Clarks Fork Yellowstone River
Lower South Fork Shoshone River
Dry: 499K
Normal: 740K
Wet: 1,144K
CODY
Wood River
Shoshone River
Upper Greybull River
MEETEETSE
North Fork Dry Creek
Middle Greybull Creek
North Fork Owl Creek
FRANNIE
DEAVER
Gooseberry Creek
HOT SPRINGS
Dry Creek
Dry: 472K
Normal: 748K
Wet: 1,082K
BURLINGTON
#*
Dry: 48K
Normal: 108K
Wet: 97K
Dry: 9K
Normal: 28K
Wet: 48K
#*
Bighorn River
#*
#*
#*
Lower Greybull River
Cottonwood Creek
BIG HORN
Little Dry Creek
Porcupine Creek
Lower Shell Creek
Bighorn River
#*
Lower Fifteenmile Creek
THERMOPOLIS
Dry: 920K
Normal: 1,568K
Wet: 1,912K
GREYBULL
KIRBY
BASIN
Nowater Creek
Upper Shell Creek
Nowood River-Sand Creek
MANDERSON
Kirby Cr
WORLAND
#*
Paint Rock Creek
East Fork Nowater Creek
Dry: 871K
Normal: 1,303K
Wet: 1,695K
Dry: 19K
Normal: 47K
Wet: 57K
Nowood River
WASHAKIE
SHERIDAN
Dry: 249K
Normal: 296K
Wet: 425K
Tensleep Creek
TEN SLEEP
Buffalo Creek
RANCHESTER
DAYTON
Deep Creek
JOHNSON
Spring Creek
East Fork Wind River
DUBOIS
Torrey Creek
Dry: 6K
Normal: 40K
Wet: 64K
Wind River
PINEDALE
SUBLETTE
Sand Draw
#*
Dry: 14K
Normal: 108K
Wet: 162K
#*
Bull Lake Creek
Crow Creek
#*
Dry: 27K
Normal: 88K
Wet: 137K
Dry: 12K
Normal: 63K
Wet: 95K
Dry: 75K
Normal: 250K
Wet: 471K
#*
Popo Agie River
PAVILLION
LANDER
Fivemile Creek
FREMONT
#*
HUDSON
#*
RIVERTON
Lower Badwater Creek
#*
Dry: 68K
Normal: 108K
Wet: 168K
SHOSHONI
Dry: 332K
Normal: 749K
Wet: 987K
Poison Creek
Upper Poison Creek
Upper Badwater Creek
NATRONA
Little Popo Agie River
#
Dry: 0K
Normal: 50K
Wet: 100K
LEGEND
Available Flow Marker
Physically Available Flow,
thousand ac-ft
7-25
"
Figure 7-7
Wind/Bighorn River Basin
Physically Available Flows

FRANNIE
DEAVER COWLEY
LOVELL
BYRON
POWELL
PARK
BIG HORN
CODY
BURLINGTON
GREYBULL
BASIN
Wind/Bighorn
MANDERSON
WORLAND
TETON
HOT SPRINGS
KIRBY
Snake/Salt
DUBOIS
THERMOPOLIS
JACKSON
ALPINE
PAVILLION
SHOSHONI
RIVERTON
THAYNE
FREMONT
PINEDALE
LANDER
HUDSON
AFTON
SUBLETTE
BIG PINEY
LINCOLN
LA BARGE
COKEVILLE
Bear
Green
KEMMERER
OPAL
SUPERIOR
WAMSUTTER
GRANGER
SWEETWATER
ROCK SPRINGS
GREEN RIVER
UINTA
EVANSTON
LYMAN
MOUNTAIN VIEW
Laramie
County
LEGEND
Platte
County
Prairie
Center
RANCHESTER
DAYTON
SHERIDAN
SHERIDAN
HULETT
CLEARMONT
BUFFALO
Powder/Tongue
CROOK
CAMPBELL
GILLETTE
MOORCROFT
SUNDANCE
PINE HAVEN
UPTON
TEN SLEEP
JOHNSON
WASHAKIE
WRIGHT
KAYCEE
Northeast
WESTON
NEWCASTLE
MIDWEST
NIOBRARA
NATRONA
ROLLING HILLS
CONVERSE
GLENROCK
MILLS CASPER
MANVILLE
LUSK
DOUGLAS LOST SPRINGS
VAN TASSELL
GLENDO
PLATTE
HARTVILLE
GUERNSEY
BAIROIL
FORT LARAMIE
LINGLE
MEDICINE BOW
HANNA
Platte
TORRINGTON
WHEATLAND
GOSHEN
YODER
RAWLINS SINCLAIR
CHUGWATER
ROCK RIVER
CARBON ELK MOUNTAIN
LA GRANGE
ALBANY
SARATOGA
ALBIN
LARAMIE
BURNS PINE BLUFFS
ENCAMPMENT
LARAMIE CHEYENNE
BAGGS
DIXON
"
Figure 7-8
Groundwater Control Areas
7-26

8.0 OPPORTUNITIES
8.1 INTRODUCTION
Previous chapters of this report quantify water resources available
for development and use and identify present and future water needs in the
basins. The list of water use opportunities presented in this chapter is
intended to be used by potential project sponsors and other organizations that
need to develop a water supply to satisfy their specific needs.
Opportunities, for the most part, came from basic project planning.
The opportunities were placed on a list and information on each opportunity
was entered into a matrix for each of the river basin planning areas. The
matrix allowed evaluation of a specific opportunity relative to similar or
related opportunities. The methodology evaluates opportunities as to
whether they are desirable, functional, and capable of receiving the support
required for development.
The procedure used to complete this task consists of the following steps:
1. Use screening criteria developed in the basin plans to evaluate future water use opportunities.
2. Use a long-list of future water use opportunities developed in the basin plans.
3. Use a short-list of future water use opportunities developed in the basin plans.
4. Evaluate the opportunities on the short list.
5. Develop a Framework Scoring Matrix of advanced opportunities, specifically for the
Framework Water Plan, where appropriate.
8.2 SCREENING CRITERIA FROM THE BASIN PLANS
The process of screening water use opportunities was conducted in a progressive manner in six of
the seven basin plans. This process had not been performed for the Bear River Basin. The screening
process was developed in the following manner unless noted in the individual basin discussions.
8.2.1 Long List of Future Water Use Opportunities
During preparation of the six basin plans (Bear River Basin excluded), long lists of future water
use opportunities were initially prepared using information from published reports available for the
planning area. The level of information and data available for the projects identified through the literature
review varied from very sketchy to completed conceptual designs. Comments and suggestions received
from members of the Basin Advisory Group (BAG) contributed to the development of the final version of
the long list.
8-1

8.0 OPPORTUNITIES
8.2.2 Short List of Future Water Use Opportunities
Generally, the next step in each basin was to prepare a ranked short list of opportunities. In this
step, six criteria were evaluated to present an overall picture of the favorability of a project or
opportunity. These criteria were evaluated using a matrix approach and those matrices have been
included as various tables in this chapter. It should be noted that each basin used slightly different
scoring methods. Therefore, the matrix scoring cannot be compared across basins. The following
sections summarize the evaluation criteria.
Water Availability
This criterion reflects the general ability of a project to function given likely bypasses for prior
rights and environmental uses. It is not a reflection of the relative size of a project.
Financial Feasibility
This criterion reflects the effects of the combination of technical feasibility (high or low
construction cost) and economic use to which the water would be put (e.g., irrigation of native meadow
versus cultivation of alfalfa or row crops). The intent of this ranking is to indicate the likely ability to
afford the project or meet Wyoming Water Development Commission (WWDC) or other funding source
criteria. A low number represents a project with a cost so high that it would be difficult to finance,
whereas a high number represents a project that should more easily meet funding and repayment
requirements.
Public Acceptance
This criterion reflects the extent to which a project will encounter or create public controversy
(low number) versus a project that would likely engender broad public support (high number). For
example, on-stream storage in environmentally sensitive areas would be very controversial, while offchannel
storage in less sensitive areas would more likely be supported.
Number of Sponsors/Beneficiaries/Participants
Under this criterion, all other things being equal, a project serving a larger segment of the
population would rank higher (higher number) than one serving only a few people (lower number).
Legal/Institutional Concerns
This criterion reflects the perceived relative ease (high number) or difficulty (low number) with
which a project could be authorized and permitted under existing state and federal law.
Environmental/Recreational Benefits
This criterion reflects the net effect of positive environmental and recreational aspects of a project
as offset, to the extent it can be determined, by potential negative impacts on these attributes.
8.2.3 Framework Scoring Matrix
A Framework Scoring Matrix was developed specifically for this Framework Water Plan to allow
comparison of potential projects that had come into play since publication of the basin plans (Green,
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8.0 OPPORTUNITIES
Northeast, Wind/Bighorn) and to evaluate opportunities in the Bear River that had not been previously
ranked. This scoring matrix includes both monetary and non-monetary factors.
Monetary Factors
! Size – reservoir size in acre-feet.
! Irrigated Acreage – presently irrigated acreage.
! 2007 Total Project Costs – project costs updated to 2007.
! Unit Cost – project costs divided by project size.
! Sponsor’s Cost – cost per irrigated acre per year assuming WWDC financing (two-thirds
grant, one-third loan at 4 percent for 20 years).
! Comments
Non-monetary Factors
! Need – project need based on shortages.
! Water Availability – availability of water.
! Project Ability to Meet Need – project location and size relative to needs.
! Multiple Use Potential – potential for recreation, flood control, water quality improvement,
etc.
! Geotechnical Feasibility – preliminary geotechnical evaluation.
! Land Ownership – preliminary evaluation of landownership issues.
! Cultural Resources – preliminary evaluation of impacts.
! Environmental Impacts –preliminary evaluation of impacts on wetlands, riparian habitat,
wildlife, etc.
! Ability to Permit – comparative evaluation of potential for successful project permitting.
! Cost – relative evaluation of project costs versus project benefits.
! Total – total of non-monetary factor scores.
Each of the non-monetary factors was assigned a weighted value that reflects the importance of
that factor to project feasibility, and each potential project was assigned a score from 0 to 10 for each
factor.
8.2.4 Agricultural Needs
Chapter 6 outlines the projected future water needs for the seven river basin planning areas in the
state. Agriculture is the major water user in the state and exhibits the bulk of the seasonal shortage needs
across the state.
The estimates of existing agricultural need used in the Framework Scoring Matrix were based
upon full supply requirements. Full supply requirements were determined by applying the irrigation
water requirement to the actual irrigated acreage. The water requirement derived from this calculation
was compared to the historical diversions during dry years. The difference between the full supply
requirement minus the historical diversion is the estimated shortage.
The results of the agricultural water use estimates were used as inputs to the water availability
models prepared for the planning effort as discussed in Chapter 7. The modeling was used to determine
the availability of excess flows for future development and also as a means of determining where there
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8.0 OPPORTUNITIES
are needs for supplemental water supplies under existing conditions. The need for these supplemental
supplies should be consistent with irrigators’ perceptions of those needs. The diversion records during
non-supply-limited conditions (wet years) were used in the planning area as a measure of the level of
supply that irrigators have settled on, under existing conditions, as a balance between maximizing crop
yields and conserving limited resources. This is defined here as the “full supply diversion requirement”.
The difference between the full supply diversion requirement and the dry year diversions was used to
estimate need.
8.2.5 Potential Groundwater Development
Although there have been considerable hydrogeological investigations in the state, there have
been few regional assessments of the annual recharge, storage, and sustained yield capability of the major
aquifer systems in the state. Figure 4-9 shows the various aquifers and the basins where those aquifers
occur. Groundwater development potential of the various aquifer systems is discussed in the groundwater
section of Chapter 7.
8.3 BEAR RIVER BASIN
Future water use opportunities for the Bear River Basin are
addressed in this section.
8.3.1 Physically Available Flows
The physically available flows at locations within the basin are
provided in Table 7-2 and shown on Figure 7-1 in Chapter 7. The flows
are indicated for dry, normal, and wet years in acre-feet per year. The
available flows indicate that many of the tributaries have quite low flows in
dry years, which usually results in potential for shortages.
8.3.2 Compact Limitations
The Bear River Compact of 1978 controls the split of water on the Bear River between Wyoming,
Idaho, and Utah. The compact limitations are discussed in detail in Chapter 3. The legally available
flows for the Upper and Central Divisions are summarized in Table 7-2 in Chapter 7. Compact
provisions severely limit the available flow during dry years, particularly in the Central Basin.
8.3.3 Agricultural Needs
Almost every area of the Bear River Basin planning area can be considered water-short during
dry years. The needs identified in the Basin Plan involved existing agricultural needs. Consequently, the
opportunities are primarily focused on meeting those needs. The projected diversions and consumptive
use for high, mid, and low planning scenarios are presented in Tables 6-2 and 6-3 in Chapter 6. Table 8-1
indicates estimates of existing agricultural needs for the subbasins. The irrigated acres within those
subbasins are also indicated.
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Table 8-1 Agricultural Needs, Bear River Basin
Irrigated Lands
Needs for Dry
Hydrologic
Condition
Subbasin acres ac-ft per year
Upper Division 40,400 11,000
Central Division 23,500 12,000
8.3.4 Long and Short Lists of Future Water Use Opportunities
No specific long or short lists were developed for the Basin Plan.
8.3.5 Central Division Investigations
The Central Division of the Bear River extends from Pixley Dam to Stewart Dam in Idaho. Past
investigations for storage have been confined to Smiths Fork Creek. The most recent study, Cokeville
Reservoir Level I Study (Sunrise Engineers, Inc., 2004), analyzed six sites on the Smiths Fork: the Lower
Teichert/Bagley site, Upper Teichert/Bagley site, Smiths Fork site, Ashby site, Ferney Glade site, and
Tres Pass site. The alternatives were sized to meet irrigation shortages and varied in capacity depending
upon the locations of the drainage. The six alternatives were evaluated for various criteria. Based on the
evaluation, the Upper Teichert/Bagley site and the Smiths Fork site were advanced to preliminary design,
cost estimate, and economic analyses.
These two sites, shown on Figure 8-1, were on-channel sites with significant environmental
impacts, primarily to wetlands. The projects had no designated recreation pools, so potential multiple use
was limited.
The potential for off-channel reservoirs to lessen environmental impacts was considered in the
2004 study, but no sites were pursued. A potential site on Muddy Creek could store significant amounts
of water. The reservoir would be supplied from a seven-mile canal from the Smiths Fork. The site has
minimal wetland and aquatic resources. Most site-specific data are unavailable. The site has been
included in the secondary selection screening with data gaps indicated.
8.3.6 Upper Division Investigations
The Upper Division of the Bear River extends downstream to Pixley Dam. The shortages are
located such that storage would be most effectively located in the upper reaches, primarily in Utah. A
study was conducted in 1983 by Forsgren-Perkins Engineering for the WWDC. This study identified the
West Fork Reservoir site as the most suitable for supplemental irrigation storage.
The West Fork Reservoir site was advanced to Level III-Phase I of Final Design by 1985. The
site was investigated extensively, including geotechnical investigations, preliminary design, and
development of cost estimates. The reservoir was sized at 12,000 acre-feet and was a single-purpose
reservoir to be used for supplemental irrigation storage. The site is located approximately five miles into
Utah.
The project did not advance to construction due to sponsor financial and legal concerns. The cost
estimates of the project were updated to 2007 costs using United States Bureau of Reclamation (USBR)
cost indices. The project has favorable financial potential. The project lacks some information.
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8.0 OPPORTUNITIES
The West Fork project has the best potential for storage development in the Upper Division.
Missing data, primarily information on the ability to permit, should be acquired in order to advance the
project. The potential for a multipurpose project should be investigated which could affect reservoir
sizing. The project cost estimate should be updated and expanded to address the multipurpose concept.
8.3.7 Framework Scoring Matrix
To more fully evaluate the previously studied alternatives, a Framework Scoring Matrix was
developed. The projects included in the matrix are the Upper Teichert/Bagley site, Smiths Fork site,
Muddy Creek off-channel site from the Smiths Fork, and West Fork site. As shown on Tables 8-2 and 8-
3, the matrix indicates the shortages of information or information gaps.
8.3.8 Recommendations
The following recommendations could result in storage projects to alleviate shortages in the Bear
River Basin if sufficient interest is indicated by the BAG.
Central Division
Perform preliminary investigations and preliminary designs for a multipurpose storage project on
the Muddy Creek site. Develop the information needed for the secondary selection scoring matrix
including cost estimates and economics. The Muddy Creek Reservoir site has many data gaps but has the
best potential for development. A Level I study would be needed to determine project feasibility.
Upper Division
Update the work previously performed on the West Fork site. Develop additional information to
fill in data gaps indicated in the framework scoring matrix. This site was previously shown to have very
economical cost per acre-foot of storage. A Level II study would be needed to determine project
feasibility. A multipurpose storage project should be investigated.
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Table 8-2 Framework Scoring Matrix, Bear River Basin
Storage
Irrigated
Lands
Project
Yield
2007
Project
Cost
Storage
Cost
Sponsor
Cost per
Acre*
Sponsor
Cost per
Acre-
Foot*
Project ac-ft acres
ac-ft per
year $M $ per ac-ft $ per acre $ per ac-ft Comments
Smiths Fork Res 17,000 20,411 5,260 53.9 3,171 65 251
Smiths Fork site. 125 acres wetlands
impacted.
Upper Teichert Bagley Res 14,000 20,411 4,233 47.5 3,393 57 275
Smiths Fork site. 141 acres wetlands
impacted.
Muddy Creek Res 20,000 20,411 NA NA NA NA NA
Smiths Fork off-channel site. Sevenmile
canal required.
West Fork Res 12,000 18,700 NA 24.0 2,000 NA NA Located in Utah. 1985 updated costs.
* Assumed WWDC Standard Funding Package of two-thirds grant and one-third loan at four percent interest rate.
Table 8-3 Framework Selection Scoring, Nonmonetary Factors, Bear River Basin
Project Need
Water
Availability
Ability to
Meet
Need
Multiple
Use
Potential
Geotech
Feasibility
Land
Ownership
Cultural
Resources
Environ.
Impacts
Ability to
Permit Cost
Weight: 20 10 10 10 10 10 10 20 20 20 Total
Smiths
Fork Res 10 10 10 2 8 6 10 2 4 4 860
Upper
Teichert
Bagley
Res 10 10 9 2 8 6 10 2 4 4 850
Muddy
Creek Res 10 9 9 8 NA NA NA 8 8 4 NA
West Fork
Res 10 10 10 NA 8 8 NA NA NA 9 NA
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8.0 OPPORTUNITIES
8.3.9 Future Groundwater Development
Current groundwater withdrawal estimates indicate that, on average, less than 3,000 acre-feet per
year of groundwater is currently used in the Bear River Basin. The majority of this use is from the
alluvial aquifer. Future development of this aquifer could provide additional water to meet increased
demands; however, there are limitations and restrictions to additional depletions outlined in the Bear
River Compact. These restrictions consider withdrawals from the alluvial aquifer similar to river
withdrawals.
It is estimated that additional development in the bedrock aquifers up to 14,000 acre-feet per year
would be sustainable. Well development in the bedrock aquifers needs to be studied in greater detail to
determine the impact on Bear River flows and the extent to which compact restrictions may apply.
The current and projected groundwater use in the Bear River Basin is summarized in Table 6-15
in Chapter 6. The projections were developed for Low, Mid, and High Scenarios. The municipal and
domestic groundwater projections are summarized in Table 6-8.
8.4 GREEN RIVER BASIN
Future water use opportunities in the Green River Basin are addressed in this section.
8.4.1 Physically Available Flows
The physically available flows for the subbasins of the Green River are summarized in Table 7-2
and shown on Figures 7-2 and 7-3 in Chapter 7. The available flows were developed for dry, normal, and
wet hydrologic conditions. The available flows in the main stem of the Green River and in the major
tributaries are relatively high even in dry years. The flows on some of the smaller tributaries indicate
potential needs due to the relatively low flows in dry years.
8.4.2 Compact Limitations
Wyoming’s ability to develop and consumptively use water in the Green River Basin is primarily
constrained by the two interstate Compacts, the Colorado River Compact and the Upper Colorado River
Basin Compact. The compact limitations are discussed in detail in Chapter 3.
8.4.3 Agricultural Needs
Needs within the Green River Basin primarily occur on the
tributaries. The needs identified in the Basin Plan involved
existing agricultural shortages. Consequently, the opportunities
are primarily focused on meeting those needs. The projected
diversions and consumptive use for high, mid, and low planning
scenarios are presented in Tables 6-2 and 6-3 in Chapter 6.
Table 8-4 indicates estimates of existing agricultural needs
for the subbasins. The irrigated acres within those subbasins are
also indicated.
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Table 8-4 Agricultural Needs, Green River Basin
Tributaries
Irrigated Lands
Needs for Dry
Hyrdrologic
Condition
Subbasin acres ac-ft per year
Cottonwood Creek 23,810 13,500
Willow Creek 12,150
25,595
West Fork New Fork
7,200
East Fork New Fork 5,497 4,200
Piney Creek 38,691 18,700
Hams Fork 10,287 2,700
Horse Creek 17,372 3,900
Beaver Creek 9,660 3,900
8.4.4 Long List of Future Water Use Opportunities
The long list of opportunities developed in the Basin Plan for the Green River Basin included a
total of 75 projects. Essentially all of the projects on the list were storage projects.
8.4.5 Short List of Future Water Use Opportunities
The long list was evaluated by the BAG to develop the short list of opportunities to consider. The
short list was developed in the Basin Plan according to the following ordered set of priorities:
! Rehabilitation projects that preserve existing uses and economic dependencies.
! Projects that rectify existing demands/needs/shortages.
! Projects that meet projected future demands/needs/shortages.
! Transbasin diversions of water that enhance in-state uses.
The short list of future water use opportunities is shown in Table 8-5 and on Figures 8-2 and 8-3.
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Table 8-5 Evaluated Short List: Green River Basin
Est. Yield,
Capacity, or
Depletion 1
Project Type 3 ac-ft
Water
Availability
Financial
Feasibility
8-10
Public
Acceptance
Project Evaluation Criteria 2
No. of Sponsors/
Beneficiaries
Legal/
Institutional
Environmental/
Recreation
Benefits
Type 1 3 9 3 9 5 5
Eden Reservoir Rehabilitation 6,300 c 6 9 9 8 8 2 248
Misc. Canal Rehab (Conservation) unk 9 7 8 6 6 2 208
Middle Piney Reservoir 4,201 c 8 5 5 5 3 4 164
Sixty Seven Enlargement (off ch) 5,600 c 5 5 6 4 6 2 154
Grieve Reservoir 4,860 y 4 4 6 4 6 4 152
Type 2 8 5 8 6 10 3
Upper Green River
Green River Supplemental Supply 22,000 d 7 6 6 8 5 2 238
Sand Hill (off ch) 14,100 c 5 6 7 6 6 3 231
Fontenelle Creek Narrows 2,500 c 6 5 6 4 6 5 220
McNinch Wash (off ch) 5,600 c 5 5 7 4 6 3 214
Snider Basin 4,300 c 6 6 5 5 5 5 213
South Cottonwood 6,000 c 6 5 5 5 5 5 208
Groundwater Development unk 2 2 9 2 9 2 206
North Piney Creek 5,600 c 6 2 5 5 5 5 193
LaBarge Meadows 4,800 c 5 3 5 4 5 5 184
Warren Bridge 33,400 c 8 5 2 8 1 4 175
Fish Creek 1,400 c 3 5 5 2 5 4 163
Green River Lakes Enl.

8.0 OPPORTUNITIES
Table 8-5 Evaluated Short List: Green River Basin
Est. Yield,
Capacity, or
Depletion 1
Project Type 3 ac-ft
Water
Availability
Financial
Feasibility
Public
Acceptance
Project Evaluation Criteria 2
No. of Sponsors/
Beneficiaries
Legal/
Institutional
Environmental/
Recreation
Benefits
Groundwater Development unk 2 2 9 2 9 2 206
Storage Project unk 5 4 7 3 5 4 196
TOTAL
SCORE
Type 3 8 5 8 6 10 3
Green Below Fontenelle
Groundwater Development unk 2 2 9 2 9 2 206
Eden Project Improvements (USBR) 10,000 d 6 5 6 6 2 2 183
Seedskadee Project (USBR) 86,000 d 9 3 4 5 1 2 165
Upper Green River
Green River Supplemental Supply 22,000 d 6 6 6 8 5 2 230
Groundwater Development unk 2 2 9 2 9 2 206
East Side Project 32,000 d 6 5 4 4 3 3 168
Kendall (Upper Kendall) >100,000 c 9 5 1 8 0 4 165
Lower Kendall >100,000 c 9 5 1 8 0 4 165
New Fork Narrows >100,000 c 9 4 1 5 0 4 142
Blacks Fork /Hams Fork Rivers
Viva Naughton Enlargement 36,000 c 7 5 6 5 5 6 227
Stateline Enlargement unk 6 5 6 7 4 5 218
Meek's Cabin Enlargement unk 5 5 6 7 4 5 210
Groundwater Development unk 2 2 9 2 9 2 206
Little Snake River
Groundwater Development unk 2 2 9 2 9 2 206
Lower Willow Creek 2,700 y 5 5 5 5 4 5 190
Upper Willow Creek (CO) 1,500 y 4 5 5 4 4 5 176
Dolan Mesa Canal 2,700 d 5 3 5 3 4 4 165
Savery-Pot Hook Project (USBR) 5,000 y 6 4 4 6 1 5 161
Type 4 3 5 10 6 9 5
Green Below Fontenelle
Plains Reservoir (off ch) 100,000 c 9 4 0 7 0 3 104
New Fork Narrows >100,000 c 9 3 0 5 0 3 87
1 y = yield, c = capacity, d = depletion, unk = unknown
Each criterion has a different weighting for each type of project; 10 is most important, 1 is least important. Weighting factors are shown in bold.
Under each project, the criteria are individually scored; 10 means largely favorable, 0 is unfavorable.
Total scores are the additive result of multiplying each project criteria weighting by the associated project type criteria score.
2
Type 1: Rehabilitation projects that preserve existing uses
Type 2: Projects that rectify existing shortages
Type 3: Projects that meet projected future demands
Type 4: Projects that enhance uses in other Wyoming basins
3
8-11
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8.0 OPPORTUNITIES
8.4.6 Supplemental Studies
Reservoir studies have been commissioned by the WWDC to supplement the information
contained in the Basin Plan. These studies are summarized below.
Green River Ground Water Recharge and Alternative Storage, Level I Project
This study, performed by States West Water Resources Corporation (SWWRC, 2001)
investigated the potential for groundwater recharge and potential storage sites in the Green River Basin.
The study evaluated needs within the basin, which have been summarized earlier in this report. Screening
of the short list projects resulted in seven storage projects being investigated in detail. These sites
included the following projects, which are shown on Figure 8-2.
! Sand Hill Reservoir
! McNinch Reservoir
! East Fork River Reservoir
! East Fork Gorge Reservoir
! Church Reservoir
! Viva Naughton Enlargement
! Dempsey Basin Reservoir
Agricultural shortages within the Green River Basin are confined to the tributaries. The SWWRC
(SWWRC, 2001) report identified projects to address shortages in the East Fork of the New Fork, Hams
Fork, and the Piney Creek tributaries. The results of the secondary screening process indicate that
agriculture probably cannot afford the projects as single-purpose reservoirs. The potential for developing
these projects for multiple use should be considered. The Hams Fork projects, including the Viva
Naughton Enlargement and Dempsey Basin off-channel storage project, are currently being studied as
multipurpose projects.
Middle Piney Reservoir Rehabilitation-Level II Study
This study was commissioned by the WWDC in 2006. The objective of the study is to determine
the rehabilitation improvements necessary to utilize approximately 4,200 acre-feet of existing storage.
Dam safety issues presently preclude use of the storage.
Upper Green River Storage Study
This study was conducted by Kleinfelder, Inc. in 2007 to evaluate shortages and potential need in
the Upper Green River Basin. The study evaluated the following potential reservoirs as shown on Figures
8-2 and 8-3.
! Lower Willow Creek Reservoir (Little Snake River Basin)
! Mickelson Creek Reservoir
! Horse Pasture Draw Reservoir
! Cow Gulch Reservoir
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8.0 OPPORTUNITIES
Little Snake River Dams-Level II Study
This study was conducted by Gannett Fleming in 2003 for the WWDC. Three potential storage
sites were investigated: the Upper Willow Creek Dam and Reservoir, Upper Cottonwood Creek
Reservoir, and Grieve Reservoir Rehabilitation. The study included subsurface investigations at the
Upper Willow Creek site.
8.4.7 Framework Scoring Matrix
The sites investigated in the supplemental studies were evaluated utilizing the Framework
Scoring Matrix developed for this Plan. The results are shown in Tables 8-6 and 8-7.
Table 8-6 Framework Scoring Matrix, Green River Basin
Storage
Irrigated
Lands
Project
Yield
2007
Project
Cost
Storage
Cost
Sponsor
Cost per
Acre*
Sponsor
Cost per
Acre-Foot*
Project ac-ft acres
ac-ft per
year $M $ per ac-ft $ per acre $ per ac-ft Comments
Middle Piney
Rehab 4,200 NA NA NA NA NA NA Piney Creek drainage.
Horse Pasture
Draw Res 5,710 15,151 5,152 20.6 3,608 33 98
Sand Hill Res 14,500 10,000 14,100 32.8 2,262 80 57
Church Res 10,000 5,497 4,200 20.5 2,050 91 120
Dempsey Basin
Res 24,000 10,287 10,700 NA NA NA NA
Grieve Reservoir
Rehabilitation 400 NA 300 0.5 1,250 NA 41
Viva Naughton Enl 24,000 10,287 10,700 NA NA NA NA
North Horse Creek
drainage off-channel site.
Piney Creek drainage
off-channel site would
require 3-mile canal.
East Fork drainage offchannel
site would
require 2-mile canal;
water supply concerns.
Off-channel site; Hams
Fork drainage; critical
cultural impacts.
Little Snake drainage,
off-channel.
Hams Fork drainage;
critical cultural impacts;
large wetland impacts;
multipurpose reservoir.
Mickelson Creek
Res 7,300 19,183 5,835 31.9 4,370 41 133
Cow Gulch Res 13,330 11,583 2,793 19.5 1,463 41 170
McNinch Res 4,600 6,000 5,600 28.6 6,217 117 125
South Cottonwood Creek
drainage off-channel site.
Beaver Creek drainage
off-channel site.
Piney Creek drainage
off-channel site would
require 6-mile canal.
Lower Willow
Creek Res 23,190 10,011 5,943 45.1 1,945 110 185 Willow Creek drainage.
East Fork Gorge
Res 1,900 5,497 1,900 30.7 16,158 137 395 New Fork drainage.
East Fork River
Res 1,700 5,497 1,700 19.1 11,235 85 275 New Fork drainage.
Upper Willow
Creek 10,000 NA 4,570 22.5 2,250 NA 121
Little Snake drainage
located in Colorado.
Upper Cottonwood
Creek 1,000 NA NA 7.2 7,200 NA NA Little Snake drainage.
* Assumed WWDC Standard Funding Package of two-thirds grant and one-third loan at four percent interest rate.
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Table 8-7 Framework Selection Scoring, Nonmonetary Factors, Green River Basin
Project Need
Water
Availability
Ability to
Meet Need
Multiple
Use
Potential
Geotech
Feasibility
Land
Ownership
Cultural
Resources
Environ.
Impacts
Ability to
Permit Cost
Weight: 20 10 10 10 10 10 10 20 20 20 Total
Middle Piney
Reservoir
Rehabilitation 10 10 10 10 8 10 8 8 10 10 1,320
Horse Pasture
Draw Res 10 8 8 4 6 5 8 8 8 6 1,030
Sand Hill Off-
Channel Res 10 10 8 4 6 7 6 9 9 7 1,110
Church-New Fork
Reservoir 10 4 10 4 6 9 8 8 9 8 1,110
Dempsey Basin-
Hams Fork
Reservoir 10 8 10 6 NA 5 NA NA NA NA NA
Grieve Reservoir
Rehabilitation 8 10 8 2 8 6 NA NA NA 8 NA
Viva Naughton-
Hams Fork
Enlargement 10 8 10 8 8 10 NA NA NA NA NA
Mickelson Creek
Res 10 6 5 4 6 7 8 8 8 5 980
Cow Gulch Res 10 6 8 4 6 7 6 6 6 5 910
McNinch Wash
Off-Channel Res 4 10 4 4 6 7 5 8 8 5 860
Lower Willow
Creek Res 10 8 4 4 6 8 8 4 4 4 820
East Fork Gorge-
New Fork
Reservoir 10 10 4 4 5 8 8 6 2 1 770
East Fork New
Fork Reservoir 10 10 4 4 5 7 8 5 2 2 760
Upper Willow
Creek 8 8 8 8 8 5 NA NA NA 7 NA
Upper Cottonwood
Creek 4 NA NA NA 6 NA NA NA NA 2 NA
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8.0 OPPORTUNITIES
8.4.8 Recommendations for Storage Opportunities
Piney Creek Drainage and Tributaries
Two projects that could meet most of the needs on the drainage have been identified in the
Framework Scoring Matrix as the best alternatives.
Sand Hill Off-Channel Reservoir
This site is off-channel and would be supplied by a three-mile canal from Middle Piney and South
Piney Creeks. The proposed storage was 14,500 acre-feet as a single-purpose reservoir for agriculture.
This potential storage project had the third highest matrix score in the basin and relatively low cost per
acre-foot of storage. A Level II study would be needed to determine the feasibility of this project. The
potential for a multipurpose reservoir should be investigated.
Middle Piney Reservoir Rehabilitation
This rehabilitation project would allow storage of 4,200 acre-feet. This project had the highest
score in the basin and will have a very low cost per acre-foot of storage. The Level II study currently in
progress will develop the information necessary to determine project feasibility.
East Fork of the New Fork Drainage (Church Off-Channel Reservoir)
One project, the Church Reservoir off-channel site, has been identified as the best alternative to
meet the needs on this drainage. This site would be supplied by a canal from tributaries of the East Fork
River and could store a maximum of 10,000 acre-feet. This site is an alternate to the other two East Fork
sites. This potential storage project had a high matrix score in the basin and reasonable costs per acrefoot
of storage. This reservoir would need to be advanced with a Level II study. Geotechnical concerns
and water supply concerns need to be addressed to determine project feasibility.
Hams Fork Drainage
Two projects are currently being investigated to meet the shortages on the Hams Fork. The Viva
Naughton Reservoir Enlargement and the Dempsey Basin off-channel reservoir would meet needs of the
irrigators, municipalities, and Naughton Power Plant. The current study will determine the best
alternative to meet the needs. Cultural issues have been encountered at both sites. This project will be
advanced with a Level II study in 2007 to determine the preferred alternative and project feasibility. The
two sites were similar in scoring and cost, and either project would meet the needs of the drainage.
Viva Naughton Enlargement
This existing reservoir is located on the Hams Fork. A potential enlargement of 24,180 acre-feet
has been proposed for agricultural, municipal, and industrial uses.
Dempsey Basin Reservoir
This site is an off-channel alternative to Viva Naughton and would be supplied by a canal from
the Hams Fork upstream of Viva Naughton. A size of 24,180 acre-feet was proposed.
8-15

8.0 OPPORTUNITIES
Cottonwood Creek Drainage (Mickelson Creek Off-Channel Reservoir)
One project, the Mickelson Creek Reservoir, has been identified as the best alternative to meet
the needs in this drainage.
This potential storage project is off-channel and would require an approximately one-mile
diversion canal from South Cottonwood Creek. The proposed storage capacity was 7,300 acre-feet. This
project, although mid-range in scoring and cost, is the best alternative in the drainage. A Level II study
would be needed to determine the feasibility of this project. The potential for a multipurpose reservoir
should be investigated.
Horse Creek Drainage (Horse Pasture Draw Off-Channel Reservoir)
One project, the Horse Pasture Draw Reservoir, has been
identified as the best alternative to meet the needs in this drainage.
This potential storage project is off-channel and would require an
approximately one-mile diversion canal from North Horse Creek. The
proposed storage capacity was 5,710 acre-feet. This project is in the
mid range in scoring and costs but is the best alternative in the
drainage. A Level II study would be needed to determine the
feasibility of this project. The potential for a multipurpose reservoir
should be investigated.
Beaver Creek Drainage (Cow Gulch Off-Channel Reservoir)
One project, the Cow Gulch Reservoir, has been identified as the best alternative to meet the
needs in this drainage. This potential storage project is off-channel and would require an approximate
four and one-half mile canal to divert water from Middle Beaver Creek and South Beaver Creek. The
proposed storage capacity was 13,330 acre-feet. This site was not highly rated but is the best alternative
identified in the drainage. A Level II study would be needed to determine the feasibility of this project.
The potential for a multipurpose reservoir should be investigated.
8.4.9 Future Groundwater Development
There is virtually no information on the overall groundwater basin water budget, such that major
inflow and outflow components may be quantified. Accordingly, it is difficult to evaluate the Green River
Basin’s safe, long-term yield for purposes of defining future groundwater development potential.
The basin has a total area of about 20,000 square miles (12.8 million acres). However, there are
large areas of the basin in which potential evapotranspiration (ET) significantly exceeds average rainfall.
For purposes of this analysis, it is assumed that recharge is effectively zero in areas where ET
significantly exceeds rainfall. In the remaining parts of the Basin, mainly the mountain and foothills areas,
rainfall exceeds potential (ET). These areas have been mapped and are estimated to have an area of
approximately 925,000 acres. The average “surplus” rainfall (where annual rainfall exceeds annual ET) is
assumed to be about 6 inches. It is also assumed that approximately 10 percent of the surplus rainfall
recharges the groundwater system. This approach yields an estimate of about 50,000 acre-feet per year of
groundwater recharge, which is considered to be an approximation of basin groundwater yield. These
estimates neglect the potential for interbasin movement of groundwater. They also neglect the large
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8.0 OPPORTUNITIES
quantity of groundwater in storage that could potentially be developed without experiencing significant
basinwide impacts.
By comparison, the USGS (Martin, 1996; Glover, et al; 1998) estimates approximately 100,000
acre-feet per year of groundwater recharge by precipitation to the Tertiary-age rocks. For planning
purposes, it is concluded that basin yield is on the order of between 50,000 and 100,000 acre-feet per
year.
Currently, there is no evidence to suggest overdevelopment of the principal aquifer systems. It
could be concluded that there is significant potential for additional development of these aquifer systems,
with little risk of depleting this resource. However, the lack of overdevelopment actually means there is a
smaller chance that aquifer storage and retrieval techniques will be successful.
There are many factors that may affect future development and availability of groundwater
resources. In the case of the Quaternary-age alluvial aquifers, any future development of groundwater
resources may be expected to have a direct and near-immediate impact on the adjacent rivers and streams
within the alluvial system. Another factor is the potential development of groundwater associated with the
coal bed methane (CBM) extraction industry.
The current and projected groundwater use in the Green River Basin is summarized in Table 6-15
in Chapter 6. The projections were developed for Low, Mid, and High Scenarios. The municipal and
domestic groundwater projections are summarized in Table 6-8.
8.5 NORTHEAST WYOMING RIVER BASIN
Future water use opportunities for the Northeast Wyoming River Basin are addressed in this
section.
8.5.1 Physically Available Flows
The physically available flows at locations within the subbasins of Northeast Wyoming are
shown in Figure 7-4 and are summarized in Table 7-2 of Chapter 7. The available flows are indicated for
dry, normal, and wet hydrologic conditions. As indicated by the figure and table, the estimated available
flows are significantly lower in dry years than wet years in the Cheyenne River and Belle Fourche River
subbasins. Available flows in the Redwater Creek and Beaver Creek subbasins vary to a much lesser
degree from dry years to wet years. The needs in a basin are usually associated with low available flows
in dry years.
8.5.2 Compact Limitations
Three interstate compacts have been negotiated by the States of Wyoming, Montana, North
Dakota, and South Dakota for divisions of the waters of the Little Missouri River, Belle Fourche River,
and Cheyenne River. Of these three compacts, only the Belle Fourche River Compact has been formally
accepted by all interests. The provisions of this are discussed in Chapter 3 of this report. Wyoming’s
apportionment of the Belle Fourche River under the three hydrologic conditions (wet, normal, and dry
years) is summarized in Table 8-8.
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Table 8-8 Apportionment of Available Flow Per Belle Fourche River
Compact
Hydrologic
Condition
Average Annual Apportionment
Belle Fourche
River Redwater Creek Total
ac-ft
Wet Years 15,600 3,300 18,900
Normal Years 7,400 2,400 9,800
Dry Years 1,100 1,400 2,500
8.5.3 Agricultural Need
Almost every area of the Northeast Wyoming River Basin planning area can be considered watershort
during dry years. The needs identified in the Basin Plan involved existing agricultural shortages.
Consequently, the opportunities are primarily focused on meeting those needs. The projected diversions
and consumptive use for high, mid, and low planning scenarios are presented in Tables 6-2 and 6-3 in
Chapter 6.
Table 8-9 includes estimates of existing agricultural needs in dry years and the irrigated acres for
the subbasins.
Table 8-9 Agricultural Needs, Northeast Wyoming River Basin
Irrigated Lands
Needs for Dry
Hydrologic
Condition
Subbasin acres ac-ft per year
Upper Belle Fourche 3,312 8,500
Middle Belle Fourche 9,011 19,600
Lower Belle Fourche 5,584 13,600
Redwater Creek 2,213 1,400
Upper Beaver Creek 669 1,200
Middle Beaver Creek 6,000 11,200
Lower Beaver Creek 3,561 6,800
Northern Tribs to Cheyenne River 7,958 22,100
Southern Tribs to Cheyenne River 12,736 37,200
Lower Cheyenne River 2,602 6,900
Little Missouri River 9,799 31,200
Niobrara River 847 1,300
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8.5.4 Long List of Future Water Use Opportunities
The long list of future water use opportunities compiled in the Basin Plan comprised 14 projects.
The opportunities were identified in the Belle Fourche River Basin and the Cheyenne River Basin. No
opportunities were identified in the Little Missouri River Basin or the Niobrara River Basin. This list was
reviewed by the BAG to produce the short list of water use opportunities.
8.5.5 Short List of Future Water Use Opportunities
Short lists of potential projects were developed in the Basin Plan for the Belle Fourche and
Cheyenne River subbasins as shown in Tables 8-10 and 8-11. The short lists included four types of
projects:
! Type 1: Rehabilitation projects that preserve existing uses.
! Type 2: Projects that rectify existing shortages consistent with the hierarchy of preferred uses
established by the Wyoming statutes.
! Type 3: Projects that meet projected future demands consistent with the hierarchy of
preferred uses established by the Wyoming statutes.
! Type 4: Projects that enhance uses in other Wyoming basins through trans-basin diversions.
The storage projects included in the short list are shown on Figure 8-4. No specific storage
projects were identified in the Niobrara River, Little Missouri River, or the main stem of the Cheyenne
River.
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Table 8-10 Evaluated Short List: Belle Fourche River Basin
Est. Yield,
Capacity,
or
Depletion 1
Project Type 3 ac-ft
Water
Availability
Financial
Feasibility
Project Evaluation Criteria 2
Public
Acceptance
No. of
Sponsors/
Beneficiaries
Legal/
Institutional
Environmental/
Recreation
Benefits
TOTAL
SCORE
Type 1 (None)
Type 2 6 7 4 5 7 6
Inyan Kara Creek Reservoir 1,000 c 7 6 8 5 8 5 227
Enl. Driskill No. 1 Reservoir 2,800 c 7 8 6 5 5 7 224
Miller Creek Reservoir 1,000 c 6 6 8 5 8 5 221
Lytle Creek Reservoir 1,000 c 6 6 8 5 8 5 221
Blacktail Creek Reservoir 1,000 c 6 6 8 5 8 5 221
Beaver Creek Reservoir 1,000 c 6 6 8 5 8 5 221
Livingston Creek Reservoir 955 c 5 6 8 5 8 5 215
Type 3 6 8 4 5 5 6
CBM Aquifer Storage and
Retrieval unk 7 6 7 7 4 7 215
Groundwater Development unk 6 5 8 4 7 5 193
Trans-basin Diversions to
Gillette unk 8 4 7 6 3 5 183
Type 4 (None)
1 y = yield, c = capacity, d = depletion, unk = unknown
Each criterion has a different weighting for each type of project; 10 is most important, 1 is least important. Weighting factors are shown in bold.
2
Under each project, the criteria are individually scored; 10 means largely favorable, 0 is unfavorable.
Total scores are the additive result of multiplying each project criteria weighting by the associated project type criteria score.
Type 1: Rehabilitation projects that preserve existing uses
3
Type 2: Projects that rectify existing shortages
Type 3: Projects that meet projected future demands
Type 4: Projects that enhance uses in other Wyoming basins
8-20
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Table 8-11 Evaluated Short List: Cheyenne River Basin
Est. Yield,
Capacity,
or
Depletion 1
Project Type 3 ac-ft
Water
Availability
Financial
Feasibility
Project Evaluation Criteria 2
Public
Acceptance
No. of
Sponsors/
Beneficiaries
Legal/
Institutional
Environmental/
Recreation
Benefits
TOTAL
SCORE
Type 1 (None)
Type 2 7 8 5 6 4 5
Beaver Creek Reservoir (north) 7,775 c 7 4 7 5 7 7 209
Stockade Beaver Creek Reservoir 6,100 c 7 3 5 5 5 5 173
Type 3 7 8 7 7 5 6
Beaver Creek Reservoir (south) 15,000 y 6 5 6 5 6 8 237
Groundwater Development unk 5 6 5 5 7 5 218
Type 4 (None)
1 y = yield, c = capacity, d = depletion, unk = unknown
Each criterion has a different weighting for each type of project; 10 is most important, 1 is least important. Weighting factors are shown in bold.
2
Under each project, the criteria are individually scored; 10 means largely favorable, 0 is unfavorable.
Total scores are the additive result of multiplying each project criteria weighting by the associated project type criteria score.
Type 1: Rehabilitation projects that preserve existing uses
3
Type 2: Projects that rectify existing shortages
Type 3: Projects that meet projected future demands
Type 4: Projects that enhance uses in other Wyoming basins
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8.5.6 Supplemental Studies
Reservoir studies have been commissioned by the WWDC to supplement those contained in the
basin plan. These studies are summarized below.
Crook County Reservoirs and Water Management Study-Level I
The WWDC commissioned a study entitled “Crook County Reservoirs and Water Management
Study-Level I” (SEH, Inc., 2006). This study investigated potential reservoir projects located in Crook
County in the Belle Fourche River and Redwater Creek subbasins. The study included the short list
projects plus a site in the Redwater Creek subbasin. The sites investigated included the following, which
are shown in Figure 8-4.
! Blacktail Creek Reservoir
! Oak Creek Reservoir
! Pine Creek Reservoir
! Miller Creek Reservoir
! Lower Inyan Kara Creek Reservoir
! Upper Inyan Kara Creek Reservoir
! Redwater Creek Reservoir
The study developed technical information, environmental data, and estimated costs of the
reservoir sites.
Crook County Reservoir Project-Level I
The Lytle Creek Reservoir site was investigated in a separate study entitled “Crook County
Reservoir Project – Level I,” (ESA Consultants, 2006). This study investigated both technical and
monetary effects and benefits for the site.
Stockade Beaver Creek Reservoir-Level I
This study, by Bearlodge Ltd, Inc. in 1986, evaluated recreation reservoir sites on Stockade
Beaver Creek. The preferred storage site was located high in the drainage, would contain 520 acre-feet
for recreational purposes, and is shown on Figure 8 -4.
Beaver Creek Dam and Reservoir-Level I
This study, by Bearlodge Ltd, Inc. in 1989, investigated recreation reservoir sites on Beaver
Creek. Two alternative sites, the Upper and Lower Beaver Creek Reservoir sites, as shown on Figure 8-4,
were identified and investigated with storage volumes of 8,000 acre-feet and 5,026 acre-feet, respectively.
The potential reservoir sites were for recreational purposes.
Beaver Creek Dam and Reservoir Project
This study, by Bearlodge Ltd, Inc. in 1991, investigated the Upper Beaver Creek reservoir site
identified as the preferred site in the 1989 study, as shown on Figure 8-4. Geotechnical drilling and
exploration were performed on the site. Preliminary design and cost estimates were developed. The
potential reservoir site was for recreational purposes.
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8.0 OPPORTUNITIES
8.5.7 Framework Scoring Matrix
The short list storage sites previously investigated in the Belle Fourche River, Redwater Creek,
and Beaver Creek subbasins were comparatively analyzed using the Framework Scoring Matrix
developed for the Framework Plan. The information is presented in Tables 8-12 and 8-13. The
information developed in the Basin Plan and the specific reservoir studies was used for the matrix
scoring. The reservoir projects have been arranged with the highest scoring projects listed first. The
recommendations for storage opportunities were based on this information.
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Table 8-12 Framework Scoring Matrix, Northeast Wyoming River Basin Storage Opportunities
Storage
Irrigated
Lands Project Yield
2007
Project
Cost
Storage
Cost
Sponsor
Cost per
Acre*
Sponsor
Cost per
Acre-Foot
Project ac-ft acres ac-ft per year $M $ per ac-ft $ per acre $ per ac-ft Comments
Lower Beaver Creek Res 5,000 3,561 NA 10.5 2,100 72 NA
Beaver Creek site; studied
as recreational reservoir
Blacktail Creek Res 2,800 3,970 NA 17.1 6,107 106 NA Belle Fourche tributary
Lower Inyan Kara Res 12,600 5,650 NA 29.3 2,325 127 NA Belle Fourche tributary
Upper Inyan Kara Res 6,400 5,650 NA 13.3 2,078 51 NA Belle Fourche tributary
Lytle Creek Res 2,800 5,130 NA 19.5 6,964 93 NA Belle Fourche tributary
Miller Creek Res 500 5,650 NA 5.0 10,000 245 NA Belle Fourche tributary
Redwater Creek Res 16,800 13,860 NA 31.8 1,893 56 NA Redwater Creek
Oak Creek Res 3,100 571 NA 10.8 3,484 463 NA Belle Fourche tributary
Stockade-Beaver Res 520 NA NA 5.0 9,615 NA NA
Beaver Creek tributary;
studied as recreational
reservoir
Pine Creek Res 1,900 1,420 NA 7.5 3,947 97 NA Belle Fourche tributary
8-24
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8.0 OPPORTUNITIES
Table 8-13 Framework Selection Scoring, Nonmonetary Factors, Northeast Wyoming River Basin Storage Opportunities
Project Need
Water
Availability
Ability to
Meet
Need
Multiple
Use
Potential
Geotech
Feasibility
Land
Ownership
Cultural
Resources
Environ.
Impacts
Ability to
Permit Cost
Weight 20 10 10 10 10 10 10 20 20 20 Total
Lower Beaver
Creek Res 10 8 8 8 8 5 5 9 8 9 1,140
Blacktail Creek
Res (Belle
Fourche) 8 8 8 10 6 10 10 6 8 4 1,040
Lower Inyan Kara
Res (Belle
Fourche) 10 10 8 8 4 7 6 6 6 7 1,010
Upper Inyan Kara
Res (Belle
Fourche) 10 10 8 8 4 8 2 6 5 8 980
Lytle Creek Res
(Belle Fourche) 8 8 8 10 8 8 2 6 6 4 920
Miller Creek Res
(Belle Fourche) 8 6 6 8 5 8 6 8 6 4 910
Redwater Creek
Res 10 10 4 8 4 2 4 3 4 8 820
Oak Creek Res
(Belle Fourche) 4 8 2 8 6 6 10 4 5 5 760
Stockade-Beaver
Res 10 4 4 4 8 5 5 4 6 2 740
Pine Creek Res
(Belle Fourche) 6 6 4 8 4 8 4 2 2 5 640
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8.0 OPPORTUNITIES
8.5.8 Recommendations for Future Storage Opportunities
The storage opportunities in the Northeast Wyoming River Basin were developed in the
Framework Scoring Matrix. The opportunities and recommendations for advancement are discussed for
each subbasin. The storage sites are shown on Figure 8-4.
Belle Fourche River Basin
The projects that would be most beneficial to the basin would be
multiple-use projects. Potential uses could include irrigation, recreation,
fishery improvements, Keyhole Reservoir level improvements, flood
control, and water quality improvement.
The following reservoir sites are the best opportunities for
advancement for further study based on the Framework Scoring Matrix.
Upper or Lower Inyan Kara Reservoir Sites
The Upper and Lower Inyan Kara Reservoir sites were rated highly in the Belle Fourche River
basin and had the lowest costs of development per acre-foot of storage. The Upper site could store a
maximum of 6,400 acre-feet while the Lower site could store a maximum of 12,600 acre-feet. Reservoir
yield was not developed for the sites. The compact limitations on the storage size (1,000 acre-feet) would
have to be addressed. A multipurpose reservoir could benefit all of the uses indicated above. Issues of
concern with these sites include reservoir yield, geotechnical feasibility, cultural and environmental
issues, and compact considerations. A Level II study would need to be performed to determine project
feasibility.
Smaller Reservoirs
The Blacktail Creek, Lytle Creek, Oak Creek, and Pine Creek Reservoir sites could be suitable
for smaller multipurpose reservoirs. If the 1,000 acre-feet compact limitation is a limiting factor, several
smaller reservoirs could be considered. The Blacktail Creek and Lytle Creek Reservoir sites were rated
highly in the Framework Scoring Matrix, but the storage costs per acre-foot were relatively high. The
Oak Creek and Pine Creek Reservoir sites were rated low in the Framework Scoring Matrix, but the
storage costs per acre-foot were lower. Reservoir yields were not developed for the sites. Level II studies
of the sites would be needed to determine reservoir feasibility. The Lytle Creek Reservoir alternative,
which was studied in a separate Level I study, indicated considerable additional monetary benefits of
multiple use.
Beaver Creek Basin
The Lower Beaver Creek Reservoir would be the project that could meet the most needs in the
subbasin. This reservoir site was the highest rated project in the entire basin. The storage cost per acrefoot
was one of the lowest in the basin for a 5,000 acre-foot reservoir. Issues of concern include reservoir
yield, geotechnical feasibility, and environmental issues. Irrigation shortages, water quality benefits,
flood control, and recreation benefits could be realized with the project. A Level II study would be
needed to determine project feasibility.
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8.0 OPPORTUNITIES
Cheyenne River Basin
The Cheyenne River Basin was identified as having substantial irrigation needs, particularly on
the northern and southern tributaries. No opportunities on the short list would meet these needs. If
sufficient interest in the basin is indicated, a Level I study of potential storage sites could be initiated to
determine if feasible projects could meet the shortages.
8.5.9 Future Groundwater Development
The current and projected groundwater use in the Northeast Wyoming River Basin is summarized
in Table 6-15 in Chapter 6. The projections were developed for Low, Mid, and High Scenarios. The
municipal and domestic groundwater projections are summarized in Table 6-8.
8.5.10 Coalbed Methane Waters
Substantial CBM development is occurring in Northeast Wyoming, particularly in the Belle
Fourche subbasin. In view of the needs in this basin and others, the beneficial use of CBM discharge
water should be considered. The subject of CBM waters is discussed in more detail in Chapter 6.
8.6 PLATTE RIVER BASIN
Future water use opportunities for the Platte River Basin are addressed in this section.
8.6.1 Physically Available Flows
The surface water resources of the Platte River Basin are fully appropriated in that new water
rights with current-day priorities could not be expected to be reliable in average or dry years due to the
potential that they would be regulated through water rights administration to protect supplies with more
senior priority dates.
8.6.2 Institutional Limitations
Wyoming water law, the North Platte Decree, and the Platte River Recovery Implementation
Program (PRRIP) limit future water development opportunities. Therefore, it is unlikely that there will be
new projects that cause major new depletions to the system. The list of opportunities provided below is
based on this premise.
8.6.3 Needs
Existing agricultural needs were not quantified in the basin plan. However, the current and
projected water demands for the agricultural, municipal, domestic, industrial, and recreational economic
sectors were estimated. The information for the High, Mid, and Low Scenarios is presented in Chapter 6.
The projected future needs for all economic sectors, based on the Low, Mid, and High Scenarios,
are summarized in Table 8-14. The table indicates the potential range of needs in the basin.
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Table 8-14 Platte River Basin Future Needs -All Sectors
Total Annual Demand
Current 2005 Demands 2035 Demands Needs
Normal Max Normal Max Normal Max
Diversions CU Diversions CU Diversions CU Diversions CU Diversions CU Diversions CU
Demand
Scenario ac-ft per year
High 1,721,000 801,700 2,399,100 1,081,800 1,864,400 874,700 2,601,200 1,181,800 143,400 73,000 202,100 100,000
Mid 1,721,000 801,700 2,399,100 1,081,800 1,737,400 802,700 2,427,500 1,090,200 16,400 1,000 28,400 8,400
Low 1,720,900 801,500 2,399,100 1,081,800 1,681,900 770,500 2,362,100 1,053,700 -39,000 -31,000 -37,000 -28,100
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8.0 OPPORTUNITIES
8.6.4 Long List of Future Water Use Opportunities
The long list of future water use opportunities compiled in the Basin Plan comprised 21
categories of projects. This list was reviewed by the BAG to produce the short list of water use
opportunities.
8.6.5 Revised Short List of Future Water Use Opportunities
The short list of opportunities developed in the Basin Plan was divided into structural and
nonstructural opportunities. The short lists are in alphabetical order, and not in order of preference or
importance.
Structural future water use opportunities include:
! CBM.
! Groundwater augmentation – non-hydrologically connected to North Platte River surface
water.
! Improving agricultural irrigation system efficiencies.
! Modification of Pathfinder Dam and Reservoir.
! Regionalization of public water supply systems.
! Reuse alternatives--stormwater capture, storage, treatment, and management; irrigation with
treated municipal wastewater; gray water irrigation; and municipal irrigation using untreated
water.
! Snow fences.
! Transbasin diversions.
! Upper Laramie River reregulation reservoir opportunities.
Nonstructural future water use opportunities include:
! Drought response planning.
! Enhancing recreational use of water reservoirs.
! Glendo Reservoir--use of uncontracted water in Wyoming’s allocation to Glendo Reservoir
storage.
! Increasing runoff from national forests based on modified U.S. Forest Service (USFS)
policies and practices.
! Multipurpose flood control programs.
! Projects for which the maximum WWDC contribution is 50 percent of all project costs or
$25,000, whichever is less.
! Projects that provide multiple benefits and have total estimated costs of not more than
$100,000.
! Utilization of WWDC’s small water project program.
! Water banking.
! Water conservation.
! Water exchanges.
! Water right transfers.
! Weather modification.
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8.6.6 Structural Future Water Use Opportunities
Coalbed Methane Waters
The development of CBM is discussed in Chapter 6. Minimal development has occurred in the
North Platte River Basin. The largest development has occurred in the Powder River Basin. The
potential importation of CBM groundwaters to the North Platte Basin should be studied. However, the
reliability of the supply of CBM groundwaters may affect the feasibility of this alternate.
Groundwater Augmentation
Depending upon the type of groundwater use and desired quality and quantity, the aquifer
systems have potential for future development in the South Platte subbasin. The future development
potential within the South Platte subbasin is summarized below:
! The Quaternary Aquifer System has historically yielded large quantities of groundwater to wells
in the South Platte subbasin, but its development potential is limited due to its areal extent,
existing development, and Laramie County Control Area limitations.
! The Late Tertiary Aquifer System has been developed for irrigation, domestic, industrial,
municipal, and stock supplies in the subbasin, and despite its current level of use, appears to have
future development potential for additional supplies, dependent upon existing users and
determinations by Laramie County Control Area management.
! The Late Paleozoic Aquifer System has been identified as a potential source for future
groundwater development in the South Platte subbasin. Development of this aquifer system
would require a site-specific hydrogeologic investigation prior to well drilling to assess
development potential.
Areas of potential development of groundwater in the North Platte River Basin were identified in
the “North Platte River Groundwater Assessment Study” initiated by the WWDC in 2002. This study
identified 10 potential well sites to produce significant amounts of groundwater. High costs of
development would probably limit the users to municipalities or industry. The WWDC funds
development of groundwater at the request of sponsors.
The current and projected groundwater use in the Platte River Basin is summarized in Table 6-15
in Chapter 6. The projections were developed for Low, Mid, and High Scenarios. The municipal and
domestic groundwater projections are summarized in Table 6-8.
Because of the relatively high water-demands of this most populous basin in the state, the Platte
has been the subject of several large-scale studies of potential groundwater development. Specific
exploration sites have been identified for the Casper Aquifer and related formations along both flanks of
the Laramie Range, around the Hartville Uplift (near Guernsey), and along the Seminoe/Shirley
Mountains. Exploration sites have also been identified for the North Park and Ogalalla Aquifers near
Saratoga and Cheyenne, respectively.
Improving Agricultural Irrigation Systems and Control Efficiencies
The implementation of conservation measures to more efficiently use water offers the best
potential for agriculture to address shortages in the basin. The measures that have been investigated
include seepage controls, reregulation reservoirs, automated or remote controls, and evaporation
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8.0 OPPORTUNITIES
reduction. Conservation projects have been encouraged and funded by the WWDC. The improvements
can include both structural and operational measures. This concept should be continued and encouraged.
Modification of Pathfinder Dam and Reservoir
This project has the purpose of replacing 54,000 acre-feet of storage in Pathfinder Reservoir lost
to sediment by increasing the height of the existing emergency spillway by 2.4 feet. The increased
storage capacity would be separated into an Environmental Account and a Wyoming Account. Water
accruing to the Environmental Account would be Wyoming’s contribution to the PRRIP on behalf of its
water users in the Platte River Basin. Water accruing to the Wyoming Account would be used as a
supplemental municipal water supply and as replacement water to meet Wyoming’s obligation for the
pumping of wells in Goshen County as per the modified North Platte Decree.
The proposed project is currently being pursued by the State of Wyoming.
Regionalization of Public Water Supply Systems
The regionalization of public water supply systems has been encouraged by the State of
Wyoming, and several projects have been funded by the WWDC. The systems optimize the availability
of potable water and improve public health safety.
Reuse Alternatives
Municipalities have been investigating and implementing reuse of wastewater primarily for
irrigation purposes. This practice can reduce demands on water treatment systems and reduce need for
additional supply. Water right issues must be addressed for these systems because most wastewater flows
cannot be reused. The WWDC has been supporting and funding projects for reuse.
Snow Fences
The use of snow fences to trap blowing snow for the purpose of increasing runoff is being
investigated as a water resource management tool. The high percentage of blowing snow which
sublimates makes this application potentially valuable. Research is ongoing by the Rocky Mountain
Research Station, Laramie Forest Sciences Laboratory.
Transbasin Diversions
Transbasin diversions involve water transfers from water-rich basins to water-short basins. Two
alternatives have been investigated for importation of water to the North Platte River Basin. The basins
from which water might be transferred typically strongly oppose such transfers. Wyoming Statutes
require mitigation for the basin from which water is taken. In addition, transbasin diversions should not
occur unless all feasible water options have been exhausted in the basin that is to receive the water. As
there are some other existing options in the North Platte River Basin, it would be premature to pursue
transbasin alternatives. In addition, the existing demand presently does not warrant the very large
investment that would be required to permit, construct, operate, and mitigate a transbasin diversion
project. However, the following studies have been completed for transbasin diversion projects:
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Water Diversions from Wyoming’s Green River Basin (WWDC)
The WWDC staff performed a feasibility study of a transbasin diversion from the Green River
Basin to the North Platte River Basin. The yield of the project was to be 50,000 acre-feet per year.
Alternative diversion locations and routes from the Upper, Middle, and Lower Green River Basin were
analyzed. The alternatives that were determined to be the most promising were:
! Middle Basin
o Fontenelle to Sweetwater
o Fontenelle to Seminoe
! Lower Basin
o Green River to Seminoe
o Green River to Platte River
o Flaming Gorge to Seminoe
o Flaming Gorge to Platte River
Project costs and costs of delivered water have not been completed. However, the total project
costs will likely approach one billion dollars.
Wind River Export Study – Level I (ECI, 2002)
The purpose of the study was to assess the potential of exporting water from the Wind River Basin
into adjacent basins to benefit the Wind River Indian Tribes. The tribal water rights have been estimated
to yield approximately 36,000 acre-feet in dry years. The study investigated delivery of water to the
North Platte River via the Sweetwater River.
Several issues need to be recognized. The conveyance of the water to potential users could involve
substantial conveyance losses. Another aspect to consider is that the imported water could be used to
extinction which could increase the effective yield of the system. Another consideration is that the Wind
River Basin has substantial shortages and additional storage for the basin is being studied.
Upper Laramie River Reregulation Opportunities
The Laramie River is currently fully appropriated. Studies have identified storage sites within the
Upper Laramie Basin. However, the primary value of the sites would be to reduce evaporation in existing
reservoirs and help manage existing water more effectively. The reservoir alternatives have been found to
be of marginal economic benefit because of high costs.
8.6.7 Nonstructural Future Water Use Opportunities
Drought Response Planning
The current Wyoming Drought Plan (revised January, 2003), contains a response plan. This plan
was developed on the basis of information and similar plans from other states and agencies. The role of
drought assessment and response as defined in the Wyoming Drought Plan is “to be proactive and to
assist existing state, federal and local agencies to carry out their designated missions for assisting drought
affected customer groups.” (Micheli and Ostermann, 2003)
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8.0 OPPORTUNITIES
Drought response planning may be undertaken by individual farmers and ranchers as well as by
governmental agencies. Planning by individuals may “focus on things that the manager can do to reduce
risk (uncertain consequences) associated with climatic variability.” (Thurow and Taylor, 1999)
For example, operators could consider transferring their most senior water rights to their most
productive lands in order to receive the most benefit from a short water supply. The transfers would have
to be approved by the Wyoming Board of Control and there are costs associated with the preparation of
the necessary petitions; however, such transfers could prove valuable during a drought.
Enhanced Recreational Use of Water Reservoirs
Recreational use of water resources comprises a significant portion of Basin tourism.
Enhancement of recreational use could interfere with agricultural and municipal uses.
Glendo Reservoir
Wyoming is allocated 15,000 acre-feet of Glendo storage water. Approximately 4,400 acre-feet
are under a long-term contract with the USBR. Presently, the remaining 10,600 acre-feet are typically
marketed by the USBR through temporary use agreements. The WWDC is considering purchasing the
10,600 acre-feet to make it more readily available for priority purposes in Wyoming.
Increasing Runoff from National Forests
This concept would involve intensive and selective forest harvest to enhance water runoff. The
management of the National Forests for maximization of runoff is a very controversial issue. The actual
increase in runoff due to intensive forest harvest is also not clearly documented.
Multipurpose Flood Control Programs
The concept of this opportunity is to develop multipurpose projects which include flood control.
The concept of development of new storage projects on the North Platte system is greatly complicated by
the lack of water availability.
Water Banking
Water banking is an institutionalized process designed to facilitate transfer of developed water to
new uses. Wyoming has the least active water market of all prior-appropriation states. Other states have
found the concept to be an important water management tool. The State of Wyoming should investigate
the concept to determine potential benefits to the state.
Water Conservation
This concept relates to all water use opportunities. Previous discussion in Chapter 7 emphasized
agricultural conservation and municipal conservation. Conservation of water in all areas of usage will
help stretch the available supplies. All water users should practice conservation.
Water Exchanges
Water exchanges can be implemented through temporary use agreements approved by the State
Engineer’s Office (SEO). These temporary use agreements provide the opportunity for dry year leasing
whereby a municipality or industry could pay an irrigator not to produce a crop during a dry year and
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8.0 OPPORTUNITIES
transfer the historic consumptive use to meet their demands through a temporary use agreement.
Presently, temporary use agreements have a term of only two years. While the agreements are renewable,
the water should be placed back on the land at least once in every five-year period.
Water Right Transfers
Water right transfers have typically involved transferring agricultural water rights to municipal or
industrial uses. However, transfers can occur between all types of uses. Only the historic consumptive
use resulting from the implementation of the water right can be transferred to other uses. Transfers must
be approved by the Wyoming Board of Control. The transfers are not financially supported by the
WWDC.
Weather Modification
The WWDC has sponsored a pilot project for five years to study the effects of cloud seeding.
The results of the study should identify the benefits of the program. If the results confirm the predicted
increase in snowfall, the weather modification program could be a large benefit to the North Platte River
Basin.
8.7 POWDER/TONGUE RIVER BASIN
Future water use opportunities for the Powder/Tongue River Basin
are addressed in this section.
8.7.1 Physically Available Flows
The physically available flows are summarized in Table 7-2 and
shown on Figure 7-5 in Chapter 7. The flows are estimated for dry, normal,
and wet hydrologic conditions. The lower portions of the Tongue River and
Powder River Basin have substantial available flows in dry years. The upper
portions of the Basins typically have dry year available flows substantially
lower than wet year flows.
8.7.2 Compact Limitations
The Yellowstone River Compact of 1950 governs the allocation of the waters in the Powder
River and Tongue River between the states of Montana and Wyoming. The compact restrictions are
discussed in detail in Chapter 3. The unappropriated or unused total divertible flow of the Tongue River,
Powder River, and Little Powder River, after needs for supplemental supply for existing rights are met, is
allocated to Wyoming and Montana as follows:
! Tongue River: 40 percent to Wyoming, 60 percent to Montana
! Powder River and Little Powder River: 42 percent to Wyoming, 58 percent to Montana
To represent the wide range of possible interpretations, two estimates were made of Wyoming’s
remaining allocation of Tongue River water per the Yellowstone River Compact (a conservative estimate
and a liberal estimate) as summarized in Table 8-15.
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Table 8-15 Remaining Allocation of Available Flow per
Yellowstone River Compact
Hydrologic
Condition
Tongue River Basin
Conservative
Estimate
Liberal
Estimate
ac-ft
Powder River
Basin
Wet Years 163,000 189,000 211,500
Normal Years 90,000 117,000 131,100
Dry Years 40,000 67,000 74,300
8.7.3 Agricultural Needs
Almost every tributary area of the Powder/Tongue Basin planning area can be considered watershort
during dry years. The needs identified in the Basin Plan involved existing agricultural shortages.
Consequently, the opportunities are primarily focused on meeting those needs. The projected diversions
and consumptive use for high, mid, and low planning scenarios are presented in Tables 6-2 and 6-3 in
Chapter 6.
Table 8-16 indicates estimates of existing agricultural needs for the subbasins in dry years. The
irrigated acres within those subbasins are also indicated.
Table 8-16 Agricultural Needs, Powder/Tongue River Basin
Irrigated Lands
Needs for Dry
Hydrologic
Condition
Subbasin acres ac-ft per year
Little Bighorn 1,781 3,100
Tongue River 62,760 113,600
Upper Clear Creek 39,176 78,400
Lower Clear Creek (Powder River) 7,174 14,700
Upper Crazy Woman Creek 12,324 15,200
Lower Crazy Woman Creek 1,418 4,000
Upper Powder River 18,107 39,900
South Fork Powder River 2,103 4,000
Lower Powder River 6,440 21,100
Little Powder River 9,873 27,600
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8.0 OPPORTUNITIES
8.7.4 Long List of Future Water Use Opportunities
The long list of water use opportunities compiled in the Basin Plan comprised 54 projects.
Opportunities were identified in all five of the sub-basins. This list was reviewed by the BAG to produce
the short list of water use opportunities.
8.7.5 Short List of Future Water Use Opportunities
The long list was evaluated, and the short lists for each subbasin were developed in the Basin
Plan as shown in Tables 8-17 through 8-22. The short lists were broken down into the following four
types:
! Type 1: Rehabilitation projects that preserve existing uses.
! Type 2: Projects that rectify existing shortages consistent with the hierarchy of preferred uses
established by the Wyoming statutes.
! Type 3: Projects that meet projected future demands consistent with the hierarchy of
preferred uses established by the Wyoming statutes.
! Type 4: Projects that enhance uses in other Wyoming basins through trans-basin diversions.
The storage projects included in the short list are shown on Figure 8-5.
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8.0 OPPORTUNITIES
Table 8-17 Evaluated Short List: Little Bighorn River Basin
Est. Yield,
Capacity,
or
Depletion 1
Project Type 3 ac-ft
Water
Availability
Financial
Feasibility
Project Evaluation Criteria 2
Public
Acceptance
No. of
Sponsors/
Beneficiaries
Legal/
Institutional
Environmental/
Recreation
Benefits
TOTAL
SCORE
Type 1 (None)
Type 2 (None)
Type 3 6 5 6 5 8 6
BEPC Sunrise Project 82,110 c 6 7 7 5 5 6 214
Little Bighorn River Export System 29,600 y 8 7 6 7 3 5 208
Groundwater Development unk 5 6 8 4 7 4 208
Half Ounce Reservoir 10,000 y 8 6 4 5 5 3 185
Twin Creek Reservoir 38,588 c 8 6 4 4 4 4 178
Fuller No. 1 Reservoir 22,829 c 4 3 5 4 5 5 159
Fuller No. 2 Reservoir 1,549 c 4 3 5 4 5 4 153
Type 4 (None)
1 y = yield, c = capacity, d = depletion, unk = unknown
Each criterion has a different weighting for each type of project; 10 is most important, 1 is least important. Weighting factors are shown in bold.
2
Under each project, the criteria are individually scored; 10 means largely favorable, 0 is unfavorable.
Total scores are the additive result of multiplying each project criteria weighting by the associated project type criteria score.
Type 1: Rehabilitation projects that preserve existing uses
3
Type 2: Projects that rectify existing shortages
Type 3: Projects that meet projected future demands
Type 4: Projects that enhance uses in other Wyoming basins
8-37
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8.0 OPPORTUNITIES
Table 8-18 Evaluated Short List: Tongue River Basin
Est. Yield,
Capacity,
or
Depletion 1
Project Type 3 ac-ft
Water
Availability
Financial
Feasibility
Project Evaluation Criteria 2
Public
Acceptance
No. of
Sponsors/
Beneficiaries
Legal/
Institutional
Environmental/
Recreation
Benefits
TOTAL
SCORE
Type 1
Misc. Canal Rehab (Conservation) unk Not ranked, only one project of this type
Type 2
Sheridan Canal System 68,500 y Not ranked, only one project of this type
Type 3 6 8 6 7 6 6
Upper State Line Reservoir 75,000 y 8 6 7 7 6 7 265
Lower State Line Reservoir 88,000 y 8 6 7 7 6 7 265
Jones Draw Reservoir 2,500 y 5 5 8 8 7 4 240
West Fork Reservoir 2,500 y 5 5 8 8 7 4 240
Prairie Dog Reservoir 20,000 y 6 4 7 4 6 6 210
Rockwood Reservoir 93,000 y 7 7 4 5 3 5 205
Groundwater Development unk 4 4 9 4 6 4 198
North Fork Reservoir 21,600 y 7 5 5 4 3 5 188
South Fork Reservoir 13,200 y 7 5 5 4 3 5 188
Shutts Flats Reservoir 7,600 y 7 4 5 4 3 5 180
Type 4 (None)
1 y = yield, c = capacity, d = depletion, unk = unknown
Each criterion has a different weighting for each type of project; 10 is most important, 1 is least important. Weighting factors are shown in bold.
2
Under each project, the criteria are individually scored; 10 means largely favorable, 0 is unfavorable.
Total scores are the additive result of multiplying each project criteria weighting by the associated project type criteria score.
Type 1: Rehabilitation projects that preserve existing uses
3
Type 2: Projects that rectify existing shortages
Type 3: Projects that meet projected future demands
Type 4: Projects that enhance uses in other Wyoming basins
8-38
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8.0 OPPORTUNITIES
Table 8-19 Evaluated Short List: Clear Creek Basin
Type 1 (None)
Type 2 (None)
Est. Yield,
Capacity,
or
Depletion 1
Project Type 3 ac-ft
Water
Availability
Financial
Feasibility
Project Evaluation Criteria 2
Public
Acceptance
No. of
Sponsors/
Beneficiaries
Legal/
Institutional
Environmental/
Recreation
Benefits
Type 3 6 8 6 7 6 6
Lake DeSmet Enlargements 239,243 c 8 9 7 5 7 4 263
Lower Clear Creek Reservoir 30,300 y 8 5 6 6 6 7 244
B.C.L. Company Reservoir 29,300 c 7 5 6 6 6 7 238
Tex Ellis Reservoir 17,100 y 7 4 7 6 7 6 236
Tie Hack Reservoir Enlargement 7,500 c 4 5 7 8 4 7 228
Groundwater Development unk 4 3 7 3 6 5 177
Little Sour Dough Reservoir 1,642 c 4 3 4 3 3 4 135
Camp Comfort Reservoir 11,640 c 4 3 4 3 3 4 135
South Rock Creek Reservoir 13,300 c 4 3 4 3 3 4 135
Triangle Park Reservoir 3,000 c 4 3 4 3 3 4 135
Canyon Reservoir 5,000 c 4 3 4 3 3 4 135
South Clear Creek Reservoir 5,000 c 4 3 4 3 3 4 135
Lynx Park Reservoir 10,700 c 4 3 4 3 3 4 135
Sour Dough Creek Reservoir 4,500 c 4 3 4 3 3 4 135
Type 4 (None)
1 y = yield, c = capacity, d = depletion, unk = unknown
TOTAL
SCORE
Each criterion has a different weighting for each type of project; 10 is most important, 1 is least important. Weighting factors are shown in bold.
2
Under each project, the criteria are individually scored; 10 means largely favorable, 0 is unfavorable.
Total scores are the additive result of multiplying each project criteria weighting by the associated project type criteria score.
Type 1: Rehabilitation projects that preserve existing uses
3
Type 2: Projects that rectify existing shortages
Type 3: Projects that meet projected future demands
Type 4: Projects that enhance uses in other Wyoming basins
8-39
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8.0 OPPORTUNITIES
Table 8-20 Evaluated Short List: Crazy Woman Creek Basin
Est. Yield,
Capacity,
or
Depletion 1
Project Type 3 ac-ft
Water
Availability
Financial
Feasibility
Project Evaluation Criteria 2
Public
Acceptance
No. of
Sponsors/
Beneficiaries
Legal/
Institutional
Environmental/
Recreation
Benefits
TOTAL
SCORE
Type 1 (None)
Type 2 6 7 5 6 4 3
Hazelton Watershed Site "B" 3,000 acres 5 7 5 7 4 4 174
Doyle Creek Reservoir 3,000 acres 5 7 5 7 4 4 174
Hazelton Watershed Site "A" 1,580 acres 7 5 6 5 3 3 158
Type 3 6 8 5 6 5 6
Crazy Woman Reservoir 10,500 y 7 6 6 6 5 5 211
Lower Crazy Woman Reservoir 67,200 y 7 4 6 7 4 6 202
North Fork Crazy Woman Reservoir 2,759 c 6 5 5 4 6 4 179
Enl. Negro Creek Reservoir 13,900 c 7 5 5 5 3 4 176
Groundwater Development unk 4 3 7 3 6 5 161
Type 4 (None)
1 y = yield, c = capacity, d = depletion, unk = unknown
Each criterion has a different weighting for each type of project; 10 is most important, 1 is least important. Weighting factors are shown in bold.
2
Under each project, the criteria are individually scored; 10 means largely favorable, 0 is unfavorable.
Total scores are the additive result of multiplying each project criteria weighting by the associated project type criteria score.
Type 1: Rehabilitation projects that preserve existing uses
3
Type 2: Projects that rectify existing shortages
Type 3: Projects that meet projected future demands
Type 4: Projects that enhance uses in other Wyoming basins
8-40
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8.0 OPPORTUNITIES
Table 8-21 Evaluated Short List: Powder River Basin
Type 1 (None)
Est. Yield,
Capacity,
or
Depletion 1
Project Type 3 ac-ft
Water
Availability
Financial
Feasibility
Project Evaluation Criteria 2
Public
Acceptance
No. of
Sponsors/
Beneficiaries
Legal/
Institutional
Environmental/
Recreation
Benefits
Type 2 6 7 5 6 4 3
Morgareidge No. 7 Reservoir 4,600 acres 5 6 5 7 4 4 167
Red Fork Powder River Reservoir unk 4 4 5 6 4 4 141
Type 3 6 8 5 6 5 6
Moorhead Reservoir 35,000 y 8 7 7 6 5 6 236
Buffalo Creek Reservoir unk 8 3 7 6 7 6 214
Pumpkin Reservoir 60,000 y 6 6 6 6 6 5 210
Clarks Fork Exchange 99,700 c 8 6 6 5 3 6 207
Bass Industrial Reservoir 123,380 c 6 6 6 5 5 5 199
Arvada Reservoir 35,000 y 6 6 6 5 5 5 199
Middle Fork Powder River Reservoir 27,000 y 5 5 5 6 7 5 196
Fence Creek Reservoir 106,700 c 7 4 7 5 6 4 193
Fortification Creek Reservoir 63,300 y 5 4 7 6 6 4 187
Gibbs Reservoir 10,800 y 6 5 6 4 5 5 185
Groundwater Development unk 3 3 7 3 6 5 155
Type 4 (None)
TOTAL
SCORE
1 y = yield, c = capacity, d = depletion, unk = unknown
Each criterion has a different weighting for each type of project; 10 is most important, 1 is least important. Weighting factors are shown in bold.
2
Under each project, the criteria are individually scored; 10 means largely favorable, 0 is unfavorable.
Total scores are the additive result of multiplying each project criteria weighting by the associated project type criteria score.
Type 1: Rehabilitation projects that preserve existing uses
3
Type 2: Projects that rectify existing shortages
Type 3: Projects that meet projected future demands
Type 4: Projects that enhance uses in other Wyoming basins
8-41
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8.0 OPPORTUNITIES
Table 8-22 Evaluated Short List: Little Powder River Basin
Est. Yield,
Capacity,
or
Depletion 1
Project Type 3 ac-ft
Water
Availability
Financial
Feasibility
Project Evaluation Criteria 2
Public
Acceptance
No. of
Sponsors/
Beneficiaries
Legal/
Institutional
Environmental/
Recreation
Benefits
TOTAL
SCORE
Type 1 (None)
Type 2 (None)
Type 3 6 8 4 5 4 6
Coal Mine Reclamation Reservoirs unk 5 7 8 6 6 8 220
Groundwater Development unk 6 5 7 4 7 5 182
Type 4 (None)
1 y = yield, c = capacity, d = depletion, unk = unknown
Each criterion has a different weighting for each type of project; 10 is most important, 1 is least important. Weighting factors are shown in bold.
2
Under each project, the criteria are individually scored; 10 means largely favorable, 0 is unfavorable.
Total scores are the additive result of multiplying each project criteria weighting by the associated project type criteria score.
Type 1: Rehabilitation projects that preserve existing uses
3
Type 2: Projects that rectify existing shortages
Type 3: Projects that meet projected future demands
Type 4: Projects that enhance uses in other Wyoming basins
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8.0 OPPORTUNITIES
8.7.6 Recommendations for Storage Opportunities
The opportunities for future water use in the Powder/Tongue River Basin were primarily storage
reservoirs as shown in Figure 8-5. The opportunities and recommendations for advancement are
discussed for each subbasin.
Little Bighorn River Basin
The needs in this subbasin, which are not very great, occur in the Pass Creek subdrainage. The
short-listed storage site for this drainage, Twin Creek Reservoir, is located below most of the irrigated
lands near the state line. This storage site had a relatively low score on the short list.
Tongue River Basin
The indicated needs, which are very significant, occur in the middle portions of Tongue River,
Goose Creek, and Prairie Dog Creek, and their tributaries. The short-listed storage sites higher in the
drainages are primarily located in the Bighorn National Forest. These sites include North Fork, Shutts
Flats, South Fork, Rockwood, and West Fork Reservoirs. These reservoir sites were the lowest ranked
sites on the short list.
Three of the reservoir sites (Upper State Line, Lower State Line, and Prairie Dog) are located
near the state line. The ability of these lower reservoirs to meet the identified needs has not been
evaluated. The location of the reservoirs would require exchanges to serve the irrigated lands.
The storage projects on the short list were identified in the “Tongue River-Level I Report”
produced for the WWDC in 1985. This study was of a very preliminary nature and has numerous data
gaps. To address the needs in the Tongue River subbasin, a Level I study to review the short-listed
projects and additional projects would be needed. The demand on several existing reservoirs in the
National Forest is dropping due to the development of subdivisions. Water marketing is going on and
will likely continue.
Clear Creek Basin
The needs in the Clear Creek Basin, which are very significant, occur primarily in the upper basin
portion above Lake DeSmet. Short-listed sites in the upper basin are located primarily in the National
Forest. Sour Dough Creek Reservoir, Lynx Park Reservoir, South Clear Creek Reservoir, Canyon
Reservoir, Triangle Park Reservoir, South Rock Creek Reservoir, Camp Comfort Reservoir, Little Sour
Dough Reservoir, and Tie Hack Reservoir Enlargement are all located on Bighorn National Forest lands.
Of the sites, only the Tie Hack Reservoir Enlargement had a reasonably good score. All these sites have
questionable water supply due to the overappropriated condition of the basin.
If sufficient interest is present in this drainage, a Level I study should be pursued to evaluate the
potential sites. Alternative sites outside of the forest lands including off-channel sites should be
considered.
Crazy Woman Creek Basin
The needs were identified primarily in the upper portions of Crazy Woman Creek. To be
effective, storage would need to be located relatively high on the upper tributaries of the North Fork,
Middle Fork, and the South Fork. Three short-listed sites are located in these areas: Doyle Creek
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8.0 OPPORTUNITIES
Reservoir, North Fork Crazy Woman Reservoir, and Negro Creek Reservoir Enlargement. These three
reservoir sites did not score very well on the short list evaluation.
If sufficient interest is present in this drainage, a Level I study should be pursued to evaluate the
potential sites. Off-channel sites should also be investigated.
Powder River Basin
The needs were identified primarily in the upper portions of the
Powder River Basin. Storage would be most effectively located in the North
Fork, Middle Fork, and the South Fork of the Powder River. Four sites were
short-listed that are located in this area: Morgareidge No. 7 Reservoir, Buffalo
Creek Reservoir, Middle Fork Powder River Reservoir, and Red Fork Powder
River Reservoir. The highest rated reservoir site was the Buffalo Creek
Reservoir of unknown size. The Middle Fork of the Powder River site has
been extensively studied and is a technically feasible reservoir site. However,
opposition to the project has stymied development. The Morgareidge No. 7
Reservoir on Beaver Creek was not rated very high, nor was the Red Fork Powder River Reservoir.
If sufficient interest is present in this drainage, a Level I study should be pursued to evaluate the
potential sites. Off-channel sites should also be considered.
Little Powder River Basin
No specific projects were identified.
8.7.7 Future Groundwater Development
The aquifer system descriptions provided in Section 8.2.5, Potential Groundwater Development,
apply to the Powder/Tongue River Basin. The current and projected groundwater use in the
Powder/Tongue River Basin is summarized in Table 6-15 in Chapter 6. The projections were developed
for Low, Mid, and High Scenarios. The municipal and domestic groundwater projections are summarized
in Table 6-8.
8.7.8 Coalbed Methane Waters
The Powder River Basin has experienced rapid growth of CBM development. To date, the
development has not occurred in the areas of identified need. However, the potential for beneficial use of
CBM discharge waters should be considered. The subject of CBM water is discussed in more detail in
Chapter 6.
8.8 SNAKE/SALT RIVER BASIN
Future water use opportunities for the Snake/Salt River Basin are addressed in this section.
8.8.1 Physically Available Flows
The physically available flows are shown at significant locations within the Snake and Salt Rivers
on Figure 7-6 in Chapter 7. The irrigated acreages are summarized in Table 8-23. As indicated in Table
8-24, the Snake/Salt River Basin has very significant physically available flows, which are not legally
available.
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8.0 OPPORTUNITIES
Table 8-23 Irrigated Acreage, Snake/Salt River Basin
Irrigated Lands
Subbasin
acres
Salt River 65,584
Snake River 33,487
Table 8-24 Available Flows, Snake/Salt River Basin
Subbasin
Salt River
Snake
River
Hydrologic
Condition
Physically
Available
Flow
ac-ft per year
Legally
Available
Flow
Dry 216,000 12,000
Normal 458,000 22,000
Wet 694,000 31,000
Dry 1,769,000 69,000
Normal 2,888,000 116,000
Wet 4,159,000 165,000
8.8.2 Compact Limitations
The Snake River Compact of 1949 limits Wyoming to diversions of 4 percent of the Wyoming-
Idaho state line flows as discussed in detail in Chapter 3. The compact limits the legally available flow to
the estimated quantities shown in Table 8-24. This severely limits the amount of flow that Wyoming can
develop.
8.8.3 Agricultural Needs
No existing needs were quantified in the Snake/Salt River Basin
Plan. However, there are indications of late season irrigation shortages,
particularly in the Salt River Basin tributaries. The projected diversions
and consumptive use for high, mid, and low planning scenarios are
presented in Tables 6-2 and 6-3 in Chapter 6.
8.8.4 Long List of Future Use Opportunities
The long list of future water use opportunities compiled in the Basin Plan comprised 50 projects.
The opportunities were identified in the Snake River Basin and the Salt River Basin. This list was
reviewed by the BAG to produce the short list of water use opportunities.
8.8.5 Short Lists of Future Water Use Opportunities
The short lists were produced for the Salt River and Snake River subbasins as shown in Figure 8-
6 and Tables 8-25 and 8-26. The short lists include opportunities in agriculture, domestic/municipal,
environmental, recreational, and industrial projects.
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8.0 OPPORTUNITIES
Table 8-25 Evaluated Short List: Salt River Basin
Project Evaluation Criteria
Project Type
Water
Availability
Financial
Feasibility
Public
Acceptance
No. of
Sponsors/
Beneficiaries
Legal/
Institutional
Environmental/
Recreation
Benefits
Agricultural
Cottonwood Lake Enl. 8 6.5 7.5 7.5 5.5 6 41
Strawberry Reservoir Enl. 8 7 6.5 5.5 5.5 6.5 39
Swift Creek Reservoir Enl. & Rehab. 8 5.5 7 6.5 5 6.5 38.5
Route Runoff/Groundwater Augmentation 9 6 7 4.5 7.5 4.5 38.5
Dry Creek Reservoir 8 5 6 6 3.5 5 33.5
Salt River Reservoir (headwaters) 8 5.5 5.5 6.5 3.5 4 33
Willow Creek Reservoir 8 6 5.5 5.5 3.5 4 32.5
Crow Creek Reservoir 8 5.5 5 5 3.5 4 31
Green Canyon Reservoir 8 5.5 5.5 4 3.5 3.5 30
Stump Creek Reservoir 8 5.5 5 4 3.5 4 30
Cedar Creek Reservoir 8 5 5 4 3.5 3.5 29
Stewart Creek Reservoir 8 5 5 4 3.5 3.5 29
Domestic/Municipal
Additional Community Water Sources 8.5 8 8 7.5 7.5 5 44.5
Meter Community Water Systems 8.5 6 5.5 6.5 8.5 4 39
Environmental
Alpine Wetlands (Greys River Area) 7.5 7 6.5 5 7 4 37
Riparian River Banks Rehab. 7.5 4.5 5 4 7 4.5 32.5
Additional Wetlands 7 5.5 6.5 4 5 4 32
River Morphology Rehab. 7.5 4 5 4 6 4.5 31
Recreational
Salt River above Narrows Reservoir 8.5 6 6.5 5.5 4.5 7.5 38.5
Cloud Seeding Operations 8 4.5 3.5 3.5 6 6.5 32
Industrial
Promote Water Bottling Opportunities 9 8 8 6 7 4 42
Facilities on Existing Irrigation Systems 7.5 6 8 6 5.5 4.5 37.5
Low Head/Open Channel Hydro Projects 7 4.5 6 4.5 4 4 30
The total score is the sum of the individual scores. No weighting factors were used.
TOTAL
SCORE 1
1
8-46
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8.0 OPPORTUNITIES
Table 8-26 Evaluated Short List: Snake River Basin
Project Evaluation Criteria
Agricultural
Project Type
Water
Availability
Financial
Feasibility
Public
Acceptance
No. of
Sponsors/
Beneficiaries
Legal/
Institutional
Environmental/
Recreation
Benefits
Spring Gulch Irrigation System Sprinkler 8 5 5 4 5 3 30
South Park Irrigation System Sprinkler 8 5 5 2 5 3 28
Cottonwood Creek Reservoir (Gros Ventre) 5 2 2 3 2 6 20
Domestic/Municipal
Additional Community Water Sources 8 8 8 8 8 8 48
Fire Protection Wells in Outlying Areas 8 8 8 8 8 6 46
Improve Winter Flood Control in Jackson 7 8 6 9 8 7 45
Meter Community Water Systems 8 5 5 8 8 5 39
Environmental
Improve Water Quality of Surface Runoff from
Developed Areas 8 7 8 7 8 5 43
Riparian River Banks Rehab. 8 6 7 7 6 6 40
Additional Wetlands 8 7 8 6 5 5 39
Transfer Grand Teton National Park Water Rights
to Instream Flow 8 7 6 7 4 6 38
Increase Flows in West Bank Spring Creeks 7 5 6 6 4 6 34
River Morphology Rehab. 8 2 2 4 2 6 24
Recreational
Snowmaking Operations 8 8 6 8 8 6 44
Make Aesthetic Ponds a Beneficial Use by SEO 8 6 6 6 5 6 37
Cloud Seeding Operations 2 4 3 2 2 7 20
Industrial
Promote Water Bottling Opportunities 9 8 8 7 6 2 40
The total score is the sum of the individual scores. No weighting factors were used.
TOTAL
SCORE 1
1
8-47
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8.0 OPPORTUNITIES
Agricultural Opportunities
The short list for the Salt River subbasin includes 11 storage
projects which are primarily located on tributaries of the Salt River. Of
these sites, seven are located on the Bridger-Teton National Forest. The
WWDC currently has a Level I study being conducted for the
Cottonwood Lake Enlargement. As indicated previously, the shortages
or needs for the alternative sites were not specifically quantified. The
available water supply for the affected tributaries was quantified.
In the Snake River subbasin, conversion of flood irrigation to sprinkler systems has normally
been funded by other state agencies. Cottonwood Creek Reservoir on the Gros Ventre was the only shortlisted
storage site.
Domestic/Municipal Opportunities
Development of additional water sources for municipal needs can be studied and funded by the
WWDC. These WWDC studies are normally on an individual community request basis. The State of
Wyoming has storage water available in Palisades Reservoir for potential development. Metering of
community water systems is normally funded by other state agencies. Flood control, is normally a
secondary benefit of storage projects as proposed for the Jackson area of the Snake River subbasin.
Environmental Opportunities
The potential environmental opportunities on the short list for the Salt River subbasin included
improvement of wetlands, riparian areas, and stream stability. The WWDC has been funding watershed
management plans which consider these opportunities as well as other opportunities. Most of the
environmental opportunities on the short list for the Snake River subbasin would fall within a watershed
management plan.
Recreational Opportunities
Recreational opportunities are normally incorporated into multipurpose storage projects as
previously discussed. WWDC-funded projects can incorporate recreational opportunities.
Industrial Opportunities
The State of Wyoming has storage water available in Palisades Reservoir for potential
development. Industrial opportunities are normally supported by the local entities.
8.8.6 Recommendations for Opportunities
If sufficient interest is indicated in the basins by the BAG, the following recommendations could
advance the short list projects.
Salt River Subbasin
A basinwide study of supplemental irrigation needs and the best projects to meet those needs
would be the most efficient way to advance the opportunities. The potential multiuse projects that most
effectively benefit the basin could be determined. Projects that benefit irrigation, municipal needs,
recreation, and environment would have the best potential for implementation.
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8.0 OPPORTUNITIES
A Level I study of potential multipurpose storage projects in this subbasin would be needed to
advance potential projects. The information needed to advance project opportunities would include need,
water availability, ability to meet needs, multiuse potential, geotechnical feasibility, landownership issues,
cultural resource impacts, environmental impacts, ability to permit, estimated costs, and economics.
Watershed management opportunities could be incorporated in potential projects.
Snake River Subbasin
Watershed management plans would be the most beneficial opportunity in this subbasin. These
plans could incorporate the more diverse opportunities in this basin.
8.8.7 Future Groundwater Development
As a practical matter, the availability of groundwater is a local and project-specific function of
competing users, water quality needs, economics, and legal constraints. Nonetheless, a few general
conclusions can be made:
! The availability of groundwater across the Snake River alluvial deposits is physically limited
only by the flow of the Snake River itself (3 million acre-ft per year). Aquifer permeability is
sufficient, in most areas, to support production rates on the order of 1,000 gpm from
individual wells. It is unlikely that groundwater development from this aquifer will impact
surface flows sufficiently to trigger concerns about the volume of the combined water
resource over any reasonable planning horizon. "Local water supplies are, in most cases,
readily available through groundwater development. While each water supply system
presents unique hydrogeologic and engineering concerns, the need for long-distance
conveyance of water from areas of supply to areas of use is relatively unlikely" (Jorgensen et
al., 1999). A more likely constraint on groundwater development in this area is the
incremental deterioration of groundwater quality that accompanies the establishment of
increasing domestic, municipal, commercial, and other uses.
! In Star Valley, the alluvial aquifer is much less thick than along the Snake River and is above
the groundwater table in many areas. Successful well development across the valley floor has
been primarily based on the highly variable Salt Lake Formation. Development experience
with this formation demonstrates that high-volume wells are possible, but that careful, sitespecific
exploration is necessary and that groundwater of adequate quantity and quality may
not be available at all sites.
! Springs issuing from bedrock units on the east side of Star Valley have been extensively
developed and, with adequate safeguards with respect to water quality, can be expected to
continue.
! Bedrock aquifers in upland areas provide a full spectrum of groundwater development
potential, from low permeability and low quality to highly productive aquifers with good
water quality. Due to the complexities of the study area bedrock geology, these conditions
are quite site-specific and can change dramatically over short distances. Detailed, sitespecific
evaluations and exploratory drilling should be anticipated in areas where
groundwater is anticipated from these units.
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8.0 OPPORTUNITIES
The current and projected groundwater use in the Snake/Salt River Basin is summarized in
Table 6-15 in Chapter 6. The projections were developed for Low, Mid, and High Scenarios.
The municipal and domestic groundwater projections are summarized in Table 6-8.
8.9 WIND/BIGHORN RIVER BASIN
Future water use opportunities for the Wind/Bighorn River Basin are addressed in this section.
8.9.1 Physically Available Flows
The physically available flows are summarized in Table 7-2 and shown on Figure 7-7 in Chapter
7. The flows are estimated for dry, normal, and wet hydrologic conditions. The information indicates
that the Upper Wind River and its tributaries, including the Little Wind River and Owl Creek, have very
low dry year available flows in comparison to wet years. The needs in a basin usually are associated with
the low available flows in dry years.
8.9.2 Compact Limitations
Within the Wind River, Clarks Fork, and Bighorn Basins, surface water usage and flow are
regulated by the Yellowstone River Compact of 1950, the general adjudication of all rights to use water in
the Bighorn River system, and the State of Wyoming in the District Court, Fifth Judicial District, Civil
Case No. 4993. The compact limitations are discussed in detail in Chapter 3. The unappropriated waters
in the tributaries, after meeting existing water rights (1950) and supplemental supply for existing rights,
as measured at gages near the confluence, are allocated as follows:
! Bighorn: 80 percent Wyoming, 20 percent Montana
! Clarks Fork: 60 percent Wyoming, 40 percent Montana
The compact’s effects on available flows are shown in Table 7-2 in Chapter 7.
8.9.3 Agricultural Needs
Significant areas of the Wind/Bighorn River Basin planning area can be considered water-short
during dry years. The needs identified in the Basin Plan involved existing agricultural needs.
Consequently, the opportunities are primarily focused on meeting those needs. The projected diversions
and consumptive use for high, mid, and low planning scenarios are presented in Tables 6-2 and 6-3 in
Chapter 6.
Table 8-27 indicates estimates of existing agricultural shortages for the subbasins. The irrigated
acres within those subbasins are also indicated.
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8.0 OPPORTUNITIES
Table 8-27 Agricultural Needs, Wind/Bighorn River Basin
Irrigated Lands
Needs for Dry
Hydrologic
Condition
Subbasin acres ac-ft per year
Clarks Fork 18,299 30,000
Upper Wind River 138,863 193,000
Little Wind River 45,536 98,000
Lower Wind River 12,919 21,000
Upper Bighorn River 63,150 12,000
Owl Creek 17,839 40,000
Nowood River 21,725 7,000
Lower Bighorn River 25,862 27,000
Greybull River 98,046 29,000
Shoshone River 158,187 29,000
Bull Creek NA 193,000
Dinwoody Creek NA 193,000
Middle Fork Popo Agie River NA 22,000
North Fork Little Wind River NA NA
Shell Creek NA 1,000
8.9.4 Long List of Future Water Use Opportunities
The long list of future water use opportunities compiled in the Basin Plan comprised
approximately 300 projects. This list was reviewed by the BAG to produce the short list of water use
opportunities.
8.9.5 Short List of Future Water Use Opportunities
The short list of future water opportunities is summarized in Table 8-28. The ratings of the
projects are summarized in Table 8-29.
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8.0 OPPORTUNITIES
Table 8-28 Short List of Future Projects, Wind/Bighorn River Basin
Project Type Name Description Location
MUNICIPAL
Paleozoic Well Field
Paleozoic Well Field
Construct Deep Aquifer Supply
Construct Deep Aquifer Supply
Regionalization:
Lander/Hudson/Riverton
Regionalization: Wind River
Reservation
New Source Paleozoic Well Field Construct Deep Aquifer Supply Regionalization: Hot Springs County
Bighorn Regional Joint
Powers Board
Storage Tanks/Redundant
Transmission
Distribution/Storage
HotSprings/Washakie County
Opportunities Tensleep/Hyattville Storage Tanks/Transmission Washakie County
Conjunctive Use
Aquifer Storage and
Retrieval Alluvial Aquifer Augmentation Upper Wind River/Riverton Area
Water Management
Water Conservation
AGRICULTURAL
New Source
Ground Water Control
District
Ground Water Control
District
Leak Detection
Administration of Future
Development
Administration of Future
Development
Municipal Survey and Repair of
Leaks
Riverton Area
Paintrock Anticline and Hyattville
Basinwide
Reuse of Grey Water
Nonpotable Water Irrigation of Parks/Cemeteries Basinwide
None
Bull Lake Enlargement Reservoir Enlargement Big Wind River
Dinwoody Lake Enlargement Reservoir Enlargement Big Wind River
Steamboat New Reservoir Big Wind River
Ray Lake Reservoir Enlargement Little Wind River
Little Popo Agie Off-Channel
Site 5 New Reservoir Little Popo Agie
Pumpkin Draw New Reservoir Owl Creek
Neff Park (Popo Agie Study) New Reservoir Popo Agie
Lake Creek New Reservoir Clarks Fork
Storage Opportunities Moraine Creek No. 1 New Reservoir Shell Creek
Popo Agie Master Plan
Ditch Headgate and Diversion
Improvements
Popo Agie Basin
Distribution Kirby Creek Watershed Stock Reservoirs Kirby Creek Basin
Riverton East Construct New Diversions/Ditches Wind River Basin
New Lands Westside Construct New Diversions/Ditches Bighorn Basin
Water Conservation
Basin Transfer
ENVIRONMENTAL
CULTURAL/RELIGIOUS
Midvale/LeClair
Riverton Valley
Wind River Irrigation Project
Ditch Linings/Conveyance
Improvements
Ditch Linings/Conveyance
Improvements
Ditch Linings/Conveyance
Improvements
Wind River Basin
Wind River Basin
Wind River Basin
Clarks Fork to Greybull
Drainage Storage and Pipeline Clarks Fork to Bighorn Basin
Instream Flows Admin Minimum Flows Wind and Bighorn Basin
Minimum Reservoir Pools Admin Reservoir Releases Wind and Bighorn Basin
Watershed/Habitat Improv. Water Quality Impaired Streams Bighorn Basin
Water Use by Tribes Coordinated Reservoir Releases Wind and Bighorn Basin
8-52

8.0 OPPORTUNITIES
Table 8-29 Evaluated Short List: Wind/Bighorn River Basin
Project Type Need
Water
Availability
Financial
Feasibility
Project Evaluation Criteria
Public
Acceptance
No. of
Sponsors/
Beneficiaries
Legal/
Institutional
Environmental/
Recreation
Benefits
Weighting 8 7 7 6 6 5 7
Municipal
Groundwater Development
TOTAL
SCORE Framework
(AVG) 1 Total Score 2
Madison Aquifer (Lander) 6 7 6 7 10 5 5 6.6 301
Madison Aquifer (Southern Bighorn Basin) 5 7 8 8 10 7 5 7.1 323
Distribution/Storage Opportunities
Big Horn Regional Joint Powers Board 4 7 8 8 10 7 5 7.0 315
Town of Tensleep Regionalization 8 8 6 5 6 7 5 6.4 298
Conjunctive Use
Recharge of Alluvial System Along Upper Wind River 7 8 5 5 4 4 7 5.7 270
Water Conservation
Leak Detection Program 7 8 5 5 5 9 5 6.3 287
Reclaimed Water for Irrigation 6 7 3 4 5 5 5 5.0 232
Agricultural
New Source (none)
Storage Opportunities
Bull Lake Dam Enlargement - 48,000 AF (Bighorn) 5 7.3 10 3 10 3 6 6.3 296
Dinwoody Lake Enlargement - 82,580 AF (Bighorn) 5.5 4.3 9.7 3 10 3 6 6.0 277
Steamboat - 36,000 AF (Bighorn) 5 8.5 9.9 3 10 3 6 6.5 304
Wind River East Fork No. 1 - 103,000 AF 5.9 1.9 9.2 3 10 3 6 5.6 260
Little Wind River North Fork No. 3 9.1 4.7 8.4 3 0 3 6 4.9 240
Ray Lake Enlargement - 41,650 AF (Little Wind) 9.1 2.1 8.4 5 10 6 7 6.8 315
Moraine Creek No. 1 - 1,150 AF (Shell Cr) 5 10 8.4 5 0 6 7 5.9 278
Pumpkin Draw - 2,000 AF (Owl Cr) 5 10 8.4 5 4.7 6 7 6.6 306
Lake Creek - 5,100 AF (Clarks Fork) 0 5.3 8.4 5 0 6 7 4.5 205
Distribution
Popo Agie River Master Plan 7 5 8 7 7 6 7 6.7 310
Kirby Creek Master Plan 7 5 5 7 5 7 8 6.3 289
New Lands
Westside Irrigation Project 8 6 6 7 9 5 5 6.6 304
Riverton East 8 5 6 7 9 5 5 6.4 297
Water Conservation
Line Ditches to Reduce Seepage Loss 8 8 5 8 5 5 4 6.1 286
8-53

8.0 OPPORTUNITIES
Table 8-29 Evaluated Short List: Wind/Bighorn River Basin
Project Type Need
Water
Availability
Financial
Feasibility
Project Evaluation Criteria
Public
Acceptance
No. of
Sponsors/
Beneficiaries
Legal/
Institutional
Environmental/
Recreation
Benefits
TOTAL
SCORE Framework
(AVG) 1 Total Score 2
Change from Open Ditch to Pipeline 8 8 5 8 5 5 4 6.1 286
Midvale Irrigation District 8 8 7 8 6 5 4 6.6 306
LeClair Laterals 8 8 7 8 6 5 4 6.6 306
Riverton Valley Crossings 8 8 6 8 6 5 4 6.4 299
More Efficient Irrigation Systems 8 8 5 8 5 5 4 6.1 286
Low Head Sprinklers 8 8 5 8 5 5 4 6.1 286
Basin Transfer
Clarks Fork to Shoshone River Pipeline 2 10 4 5 6 6 5 5.4 245
Wood River to Gooseberry Cr Storage in Sunshine
Reservoir and Pipeline 5 6 4 5 6 6 5 5.3 241
Wood River to Cottonwood/Grass Cr Storage in
Sunshine Reservoir and Pipeline 5 6 4 5 6 6 5 5.3 241
Environmental
Environmental/Recreation
Instream or Minimum Flows 7 3 8 7 10 7 8 7.1 326
Minimum Reservoir Pool 7 3 8 7 10 7 8 7.1 326
River Restoration/Habitat Improvement 6 9 6 7 4 7 7 6.6 303
Cultural/Religious
Cultural/Religious Management
1
2
Coordinated Releases for Cultural Purposes 8 8 7 6 6 8 7 7.1 330
Coordinated Releases for Religious Purposes 8 8 7 6 6 8 7 7.1 330
This score is the average of the individual scores.
This value is the sum of individual scores multiplied by the weighting factors. This is unique to the Framework Water Plan and was calculated to create a more uniform scoring system among the basins.
8-54

8.0 OPPORTUNITIES
8.9.6 Supplemental Studies
Other studies have been conducted within the Wind/Bighorn River Basin. Brief summaries of
these studies follow.
Upper Wind River Storage Project – Level I Study
The purpose of this study (SEH, Inc., 2001) was to evaluate alternate sites for additional and/or
new storage. The study was confined to the Upper Wind River. Approximately 150 storage sites were
evaluated and rated. Five sites were advanced to conceptual design: Bull Lake Enlargement, Little Wind
River North Fork No. 3, Dinwoody Lake Enlargement, Wind River East Fork No. 1, and Steamboat. The
information from this study was the primary resource in developing the framework scoring matrix.
Popo Agie River Watershed Study – Level I Study
This purpose of this study (Anderson Consulting
Engineers, Inc., 2003) was to evaluate and describe the Popo Agie
River watershed and develop a watershed management plan. One
of the tasks was to identify and preliminarily investigate potential
storage sites. Eighteen sites were identified and investigated. One
site, Neff Park on Sawmill Creek, a tributary of Middle Popo Agie
River, was placed on the short list. This site would have a capacity
of 6,440 acre-feet.
Crowheart Area/Dinwoody Canal System – Level I Study
The purpose of this study (Nelson Engineering, 2005) was
to evaluate the Dinwoody Canal system and investigate the
feasibility of the enlargement of Dinwoody Lake. The Dinwoody Lake Enlargement portion of the study
involved boring one exploratory hole to a depth of 90 feet. The boring confirmed the existence of glacial
till to a very significant depth in the foundation. A conceptual cost estimate was developed for a reservoir
enlargement to store an additional 39,300 acre-feet.
Kirby Area Water Supply – Level I Study
The purpose of this study (Anderson Consulting Engineers, Inc., 2005) was to evaluate the
potential to divert, store, and put to beneficial use winter releases from Boysen Reservoir. Sixteen
reservoir sites were initially identified for evaluation and screening. Three sites were identified and
studied further. These were the Freeman Draw Reservoir on the Bighorn River with a 100,000 acre-foot
capacity; the Fifteenmile Creek Reservoir with a 98,000 acre-foot capacity; and the Nowater Creek
Reservoir with a 104,000 acre-foot capacity. The sites on Fifteenmile Creek and Nowater Creek would
require supply from the Bighorn River.
The study determined and confirmed that there are no shortages on the Bighorn River below the
reservoir sites. Shortages below Boysen Reservoir are on the tributaries which could not be served by
these reservoirs.
8-55

8.0 OPPORTUNITIES
Cottonwood/Grass Creek Watershed Management Plan – Level I Study
This study, currently under development, has the purpose to assess, describe, and inventory the
watershed and then to develop a management and rehabilitation plan for the watershed. One of the tasks
in the study is to assess water storage needs and potential alternative reservoir sites to meet the needs.
Owl Creek Master Plan
The purpose of this study (SEH, Inc., 2005) was to assess, describe, and inventory the watershed
and then to develop a management and rehabilitation plan for the watershed. One of the tasks was to
identify and evaluate reservoir sites. Five reservoir sites were identified as having the best potential to
meet shortages within the basin. These five sites were recommended for future study. A study is
currently in progress to analyze the alternative storage sites in detail.
Wind River Export Study – Level I
The purpose of this study (ECI, 2002) was to assess the potential of exporting water from the
Wind River Basin into adjacent basins to benefit the Wind River Indian Tribes. The study identified the
best potential for sale of the water to be the Colorado Front Range. The system investigated would
deliver 54,300 acre-feet per year to potential customers. The study also investigated delivery of water to
the North Platte River via the Sweetwater River. The compact issues concerning transbasin exportation
would have to be considered.
Ray Lake Enlargement – Level II Study
The purpose of this study (Gannett Fleming, 2005) was to assess the safety of dams issues with
the existing structure and evaluate the potential to enlarge the reservoir to provide water to areas of
existing shortage within the Little Wind River drainage. The rehabilitation of the existing dam to meet
safety of dams criteria was feasible as was enlargement of the reservoir. However, enlargement may
require realignment of the dam. The project is pending action by the sponsors.
8.9.7 Framework Scoring Matrix
The short list reservoir sites investigated in the referenced studies were evaluated utilizing the
Framework Scoring Matrix developed for the Framework Plan. The results are shown in Tables 8-30 and
8-31. The information developed in the Basin Plan and the specific reservoir studies was utilized for the
matrix scoring. The reservoir projects have been arranged with the highest scoring projects listed first.
The recommendations for storage opportunities were based on this information.
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8.0 OPPORTUNITIES
Table 8-30 Framework Scoring Matrix, Wind/Bighorn River Basin
Storage
Irrigated
Lands
Project ac-ft acres
Project
Yield
2007
Project
Cost
Storage
Cost
Sponsor
Cost per
Acre*
Sponsor
Cost per
Acre-Foot*
ac-ft per
year $M $ per ac-ft $ per acre $ per ac-ft Comments
Steamboat Off-Channel Reservoir 44,800 138,863 40,000 56.7 1,266 10 35 Tribal lands; estimated yield
Bull Lake Enlargement 48,300 138,863 30,000 42.7 884 8 35 Tribal and USBR lands; estimated yield
Ray Lake Enlargement 27,000 13,691 11,000 53.5 1,981 96 119
Dinwoody Lake Enlargement 39,300 138,863 25,000 40.4 1,028 7 40 Estimated yield
Tribal lands; resevoir includes 10,000 AF
recreation pool; supply limitations
North Fork Little Wind River No. 3
Reservoir 38,600 45,536 25,000 88.3 2,288 48 87 Tribal lands; estimated yield
Wind River East Fork No. 1 Reservoir 70,600 NA 12,000 94.4 1,338 NA 193 Tribal lands; estimated yield
Neff Park - Sawmill Creek 6,440 NA 4,000 13.5 2,096 NA 83
Middle Popo Agie drainage; located on
USFS lands; estimated yield
* Assumed WWDC Standard Funding Package of two-thirds grant and one-third loan at four percent interest rate.
Table 8-31 Framework Selection Scoring, Non-Monetary Factors, Wind/Bighorn River Basin
Project Need
Water
Availability
Ability to
Meet Need
Multiple Use
Potential
Geotech
Feasibility
Land
Ownership
Cultural
Resources
Environ.
Impacts
Ability to
Permit Cost
Weight: 20 10 10 10 10 10 10 20 20 20 Total
Steamboat Off-
Channel Reservoir 10 10 10 6 8 6 6 10 9 8 1,200
Bull Lake
Enlargement 10 8 10 6 8 4 4 8 9 8 1,100
Ray Lake
Enlargement 10 5 8 8 8 4 8 8 10 4 1,050
Dinwoody Lake
Enlargement 10 8 10 6 6 4 0 8 8 8 1,020
North Fork Little
Wind River No. 3
Reservoir 10 7 8 6 6 6 5 8 8 4 980
Wind River East
Fork No. 1
Reservoir 10 5 10 6 7 0 5 4 2 2 690
Neff Park - Sawmill
Creek 10 6 4 10 NA 2 NA NA NA 4 NA
8-57
8-57

8.0 OPPORTUNITIES
8.9.8 Recommendations for Storage Opportunities
The reservoir storage opportunities for the Wind/Bighorn River Basin are summarized by
subbasin below and the sites are shown on Figure 8-7.
Upper Wind River
The Upper Wind River has significant needs under most hydrologic conditions. The projects
identified as having the most potential for alleviating these needs include:
! Steamboat Off-Channel Reservoir: An approximately 55-foot high dam would impound
approximately 45,000 acre-feet with an estimated annual yield of 40,000 acre-feet. The
reservoir would be supplied with a nine-mile canal from the Wind River.
! Bull Lake Enlargement: Bull Lake is an existing USBR reservoir. Raising the dam 22 feet
would increase storage by 48,300 acre-feet with an estimated average annual yield of 30,000
acre-feet.
! Dinwoody Lake Enlargement: Dinwoody Lake is an existing reservoir. Raising the dam 90
feet would increase storage by 39,300 acre-feet with an estimated average annual yield of
25,000 acre-feet.
The Steamboat Off-Channel Reservoir was the highest rated storage project with a relatively low
cost per acre-foot of storage. The Bull Lake Enlargement was the second highest rated project with the
lowest cost per acre-foot of storage. The Dinwoody Lake Enlargement was the fourth highest rated
project with the second lowest cost per acre-foot of storage.
To advance these projects, a Level II study would be needed to determine feasibility. No single
project would yield adequate water to meet the previously identified needs in the Upper Wind River
Basin. Consequently, a Level II study should include all three potential projects to determine the best
solution for the basin.
Little Wind River
The Little Wind River has significant identified needs. The projects identified as having the most
potential for alleviating the needs are:
! Ray Lake Enlargement: The Ray Lake Enlargement was investigated with a Level II study in
2005. An enlargement of 27,000 acre-feet would have an estimated annual yield of 11,000
acre-feet. The existing Ray Lake is an off-channel reservoir.
! North Fork Little Wind River No. 3 Reservoir: This proposed reservoir would have a storage
capacity of 38,600 acre-feet with an estimated annual yield of 25,000 acre-feet.
The Ray Lake Enlargement was the higher rated project in the Little Wind River Basin with the
lower cost per acre-foot of storage. This project is well advanced for design and construction. The North
Fork Little Wind No. 3 Reservoir was the next highest rated project. The North Fork Little Wind No. 3
Reservoir project would need to be advanced to a Level II study to determine feasibility. The Ray Lake
Enlargement project will not meet all of the needs in the Little Wind River Basin.
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8.0 OPPORTUNITIES
Clarks Fork
The Clarks Fork has identified needs. The only project identified in the short list, the Lake Creek
Reservoir Project, would store 5,100 acre-feet. To advance this project, a Level I study would be needed.
Bighorn River
The Bighorn River has minimal needs. Storage water is available from Boysen Reservoir. The
Kirby Area Water Supply Level I study identified three alternative reservoir sites for analysis, conceptual
designs, and cost estimates. This study confirmed the lack of needs below Boysen Reservoir. No storage
sites for the Bighorn River were on the short list.
Greybull River
The Greybull River has relatively small shortages. The construction of the Greybull Valley
Project, which included the Roach Gulch Reservoir has alleviated most of the shortages. No storage sites
for the Greybull River were included on the short list.
Shoshone River
The Shoshone River has relatively small needs. No storage sites for the Shoshone River were
included on the short list. The State of Wyoming owns water in the Buffalo Bill Enlargement, which is
presently enhancing recreation benefits, and water is available for sale for future municipal and industrial
demands.
Owl Creek
The Owl Creek drainage has significant identified needs. A Level I study, “Master Plan for Owl
Creek Basin” (SEH, Inc., 2005), identified five alternative sites that showed promise for meeting the
needs. In 2006, a Level II project was commissioned to investigate the alternate storage opportunities.
8.9.9 Future Groundwater Development
While numerous hydrogeological investigations
have been conducted in the planning area, there have been
few, if any, regional assessments of the annual recharge,
storage, and sustained yield capability of the major aquifers.
General conclusions regarding the groundwater development
potential of several of the major aquifers are summarized
below.
! Subaquifers in the Quaternary Aquifer may have local development potential. Depending
upon local hydrogeologic conditions, individual well yields may typically range from 10 to
500 gpm. Water quality and susceptibility to surface water sources of contamination must be
addressed.
! The Wind River Aquifer is already heavily developed within the Wind River Basin, but
opportunities for additional groundwater development and installation of high-capacity wells
may be possible in areas not currently developed. Local water quality conditions may
constrain development in the planning area.
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8.0 OPPORTUNITIES
! The Madison Aquifer likely has the most development potential for high-yield wells. Yields
of up to 14,000 gpm have been encountered historically under flowing artesian conditions.
However, declines in local hydraulic head and large variations in the fracture and karst
permeability of this system will necessitate site-specific investigations to be conducted prior
to drilling. Drilling depths and water quality will also constrain development at specific
locations within the planning area.
! The Flathead Sandstone is another viable high-yielding aquifer in areas where the formation
can be drilled at reasonable depths. This aquifer generally has large artesian pressures, and it
has produced large artesian flows of up to 3,000 gpm. As with the Madison Aquifer, drilling
depths and water quality will constrain development at many locations throughout the basin.
The current and projected groundwater use in the Wind/Bighorn River Basin is summarized in
Table 6-15 in Chapter 6. The projections were developed for Low, Mid, and High Scenarios. The
municipal and domestic groundwater projections are summarized in Table 6-8.
8.10 REFERENCES
Gannett Fleming, Inc. 2005. Ray Lake Enlargement, Level II Final Report.
Sunrise Engineers, Inc. 2004. Cokeville Reservoir Level I Study.
States West Water Resources Corporation. 2001. Green River Ground Water Recharge and
Alternative Storage, Level I Project.
Kleinfelder, Inc. 2007. Upper Green River Storage Study.
States West Water Resources Corporation. 2001. Green River Ground Water Recharge and
Alternative Storage – Level I Project.
Glover, K.C., Naftz, D.L., and Martin, L.J. 1998. Geohydrology of Tertiary Rocks in the Upper
Colorado River Basin, Colorado, Utah, and Wyoming, excluding the San Juan Basin.
Martin, L.J. 1996. Geohydrology of Tertiary Rocks in the Green River Structural Basin in
Wyoming, Utah, and Colorado.
SEH, Inc. 2006. Crook County Reservoirs and Water Management Study – Level I.
ESA Consultants. 2006. Crook County Reservoir Project – Level I.
ECI. 2002. Wind River Export Study – Level I.
Micheli, R. and Ostermann, T. 2003. Wyoming Drought Plan.
Thurow, T.S., and Taylor, C.A. 1999. Viewpoint – The Role of Drought in Range Management.
Jorgensen Engineering and Land Surveying. 1999. Teton County Water Supply Master Plan,
Level I.
SEH, Inc. 2001. Upper Wind River Storage Project – Level I Study.
Anderson Consulting Engineers, Inc. 2003. Popo Agie River Watershed Study – Level I Study.
Nelson Engineering. 2005. Crowheart Area/Dinwoody Canal System – Level I Study.
Anderson Consulting Engineers, Inc. 2005. Kirby Area Water Supply – Level I Study.
SEH, Inc. 2005. Owl Creek Master Plan.
ECI. 2002. Wind River Export Study – Level I.
8-60

Smiths Fork
THAYNE
PINEDALE
AFTON
ID A H O
Thomas Fork
#
#
#
Muddy
Creek
COKEVILLE
Smiths Fork
Smiths
Fork
Smiths Fork Upper
Teichert-Bagley
LINCOLN
LA BARGE
SUBLETTE
Bear River
Twin Creek
KEMMERER
OPAL
SWEETWATER
GRANGER
GREEN RIVER
EVANSTON
Yellow Creek
UINTA
LYMAN
MOUNTAIN VIEW
LEGEND
# U T A H
West
Fork
Irrigated Lands
#* Future Water Use Opportunity Sites
8-61
"
Figure 8-1
Bear River Basin
Potential Reservoir Sites

JACKSON
TETON
ALPINE
PAVILLION
RIVERTON
THAYNE
Cow Gulch Res
Horse Pasture Draw Res
SUBLETTE
PINEDALE
Pole Creek
Boulder Creek
FREMONT
LANDER
HUDSON
AFTON
Mickelson Creek Res
East Fork River Res
Middle Piney Rehab McNinch Res
BIG PINEY
LINCOLN
Sand Hill Res
Alkali Creek
Church Res
East Fork Gorge Res
La Barge Creek
Eighteenmile Canyon
LA BARGE
Little Sandy Creek
Pacific Creek
COKEVILLE
Fontenelle Creek
Buckhorn Canyon
Dempsey Basin Res
Viva Naughton Enl
Shute Creek
Green River
Lower Hams Fork
KEMMERER
Lower Hams Fork
OPAL
SUPERIOR
SWEETWATER
Green River
UINTA
Little Muddy Creek
Albert Creek
Muddy Creek
Smiths Fork
Muddy Creek
Dry Muddy Creek
Cottonwood Creek
Upper Blacks Fork
LYMAN
Big Dry Creek
GRANGER
Big Dry Creek
Green River
Lower Blacks Fork
Green River
GREEN RIVER
ROCK SPRINGS
Lower Salt Wells Creek
UTA H
LEGEND
Irrigated Lands
Lower Henrys Fork
#* Future Water Use Opportunity Sites
8-62
"
Vermillion Creek
COLORA DO
Shell Creek
Figure 8-2
Green River Basin, Upper Green
Potential Reservoir Sites

BAIROIL
CARBON
SWEETWATER
RAWLINS SINCLAIR
WAMSUTTER
Mud dy Cr
Cottonwood Creek Res
Little S
C O L O R A D O
n
ake River
Save ry Cr
Lower Willow Creek
r
Battle C
Grieve Res
N. Fork Little Snake River
Upper Willow Creek
LEGEND
Irrigated Lands
#* Future Water Use Opportunity Sites
"
8-63
Figure 8-3
Green River Basin, Little Snake River
Potential Reservoir Sites

Cheyenne River
M O N T A N A
Little Missouri River
Kilpatrick Cr
CAMPBELL
GILLETTE
Wind Cr
#
#
Arch Cr
#
B
#
Belle Fourche River
Inyan Kara Cr
lacktail Cr
Lytle Creek Res
Miller Creek Res
Lower Inyan Kara Creek Res
MOORCROFT
Blacktail Creek Res
PINE HAVEN
CROOK
#
Miller Cr
SUNDANCE
#
Redwater Cr
Pine Creek Res
#
#
Redwater Creek Res
Sand Cr
Upper Inyan Kara Creek Res
Oak Creek Res
S O U T H D A K O T A
Buffalo Cr
Caballo Cr
UPTON
#
Stockade Beaver Creek Res
Skull Cr
Belle Fourche River
WESTON
Oil Cr
Stockade Beaver Cr
Beaver Cr
Black
WRIGHT
South Beaver Cr
Little Thunder Cr
tail Cr
Lodgepole Cr
Black Thunder Cr
#
Lower Beaver Creek Res
Antelope Cr
Dry Fork Cheyenne River
Cow Cr
Lightning Cr
Lance Cr
Old Woman C r
ROLLING HILLS
GLENROCK
LEGEND
CONVERSE
DOUGLAS
Irrigated Lands
#* Future Water Use Opportunity Sites
r
Walke r C
Twentymile Cr
LOST SPRINGS
8-64
NIOBRARA
MANVILLE
LUSK
"
Quinn Cr
Niobrara River
N E B R A S K A
VAN TASSELL
Figure 8-4
Northeast River Basin
Potential Reservoir Sites

BEPC Sunrise Project
M O N T A N A
Moorhead Reservoir
#
Fuller No. 1 Reservoir
(Twin Creek Reservoir) Lower State Line Reservoir
#
# # #
## Upper State Line Reservoir
Fence Creek Reservoir
Fuller No. 2 Reservoir
#
# Prairie Dog Reservoir
RANCHESTER
Lower Clear Creek Reservoir
Little Bighorn River Export
Little Bighorn River Export
Sheridan Canal System
#
Tex Ellis Reservoir
# Half Ounce Reservoir
#
#
# #
#
SHERIDAN
B.C.L. Company Reservoir
Rockwood Reservoir
##
Bass Industrial Reservoir
North Fork Reservoir
#
Arvada Reservoir
South Fork Reservoir
Jones Draw Reservoir
Gibbs Reservoir
#
Shutts Flats Reservoir
West Fork Reservoir
CLEARMONT
Lower Crazy Woman Creek Reservoir
Lake DeSmet
and Enlargements
#
#
Fortification Creek Reservoir
GREYBULL
BASIN
MANDERSON
WORLAND
BIG HORN
South Rock Creek Reservoir
Triangle Park Reservoir
South Clear Creek Reservoir
WASHAKIE
Tongue River
Big G oose Cr
Little Goose Cr
#
Canyon Reservoir
Lynx Park Reservoir
Hazelton Watershed Site "B"
###
#
# # #
Dutch Cr
Piney Cr
Bo xelder Cr
Camp Comfort Reservoir
#
Clear Cr
BUFFALO Enlarged Negro Creek Reservoir
#
Tie Hack Reservoir Enlargement
Sour Dough Creek Reservoir
Little Sour Dough Reservoir
#
North Fork Crazy Woman Reservoir
Crazy W oman Cr
Hazelton Watershed Site "A"
#
Doyle Creek
JOHNSON
Clear Cr
Crazy Woman Cr
Pow der River
Powder River
Dead Horse Cr
Wild Horse Cr
Crazy Woman Reservoir
Pumpkin Reservoir
r
Wildcat C
GILLETTE
Little Powder River
CAMPBELL
C o
t tonwood Cr
KIRBY
Red Fork Powder River Reservoir
HOT
SPRINGS
#
#
#
Middle Fork Powd er River
Buffalo Creek Reservoir
South Fork Powder River
Salt Cr
Dry Fork Powder RIver
Middle Fork Powder River Reservoir
WRIGHT
Morgareidge No. 7 Reservoir
#
MIDWEST
Castle Cr
SHOSHONI
Teapot Cr
Sa
lt C r
FREMONT
LEGEND
Irrigated Lands
South Fork Powder River
Wallace Cr
NATRONA
#* Future Water Use Opportunity Sites
8-65
CASPER
"
ROLLING HILLS
CONVERSE
Figure 8-5
Powder/Tongue River Basin
Potential Reservoir Sites

Lamar River
M O N T A N A
PARK
Snake River
TETON
Transfer GTNP Water Rights to Instream Flow
Gros Ventr e River
Increase Flows in West Bank Spring Creeks
Improve Winter Flood
Control in Jackson
Snak
e River
Spring Gulch Irrigation System Sprinkler
South Park Irrigation System Sprinkler
Cottonwood Creek Res (Gros Ventre)
FREMONT
I D A H O
Ho back R
iver
THAYNE
Alpine Wetlands (Greys River Area)
Stewart Creek Res
Green Canyon Res
Cedar Creek Res
Greys River
Swift Creek Res
Enl & Rehab
Crow Creek Res
Salt River
AFTON
Strawberry Res Enl
Willow Creek Res
Stump Creek Res
Dry Creek Res
Cottonwood Lake Enl
Salt River Res (headwaters)
MARBLETON
BIG PINEY
PINEDALE
SUBLETTE
LEGEND
Irrigated Lands
#* Future Water Use Opportunity Sites
8-66
"
Figure 8-6
Snake/Salt River Basin
Potential Reservoir Sites

MO N T A N A
Crandall Cr
Sunlight Cr
Clark s F ork Y ellowstone River
POWELL
Shoshone River
FRANNIE
DEAVER COWLEY
LOVELL
BYRON
SHERIDAN
RANCHESTER
DAYTON
PARK
North Fork S
South Fork Shoshone River
hoshone River
Greybull River
CODY
MEETEETSE
Dr y Cr
BURLINGTON
Greybull River
Shell Cr
GREYBULL
BASIN
Bighorn Rive r
MANDERSON
BIG HORN
Paint Ro
ck Cr
Nowood River
JOHNSON
Wood River
Gooseberry Cr
Fifteenmile Cr
WORLAND
Tensle ep Cr
TEN SLEEP
HOT SPRINGS
Cottonwood Cr
KIRBY
WASHAKIE
Buffa
lo Cr
Otter Cr
Kirby Cr
Du N oir Cr
DUBOIS
No rth Fork W
ind River
#
East Fork Wind River
#
Dinwo ody Cr
Wind River East Fork No. 1
#
Dinwoody Lake Enl
Bull Lake Cr
#
#
Bull Lake Enl
Steamboat Off-Channel Res
Wind River
PAVILLION
Fivemile Cr
Owl Cr
Muddy Cr
FREMONT
THERMOPOLIS
Wind River
Buffalo Cr
SHOSHONI
Badwater Cr
Poison Cr
Bridger Cr
Alkali Cr
Deep C
NATRONA
r
PINEDALE
SUBLETTE
North Fork Little Wind River No. 3 Res
#
#
Ray Lake Enl
Popo Ag
ie River
#
Little Wind River
LANDER
Neff Park Res
HUDSON
Little Popo Agie River
RIVERTON
Beaver Cr
C onant Cr
LEGEND
Irrigated Lands
#* Future Water Use Opportunity Sites
8-67
"
Figure 8-7
Wind/Bighorn River Basin
Potential Reservoir Sites

9.0 PROJECT FUNDING
9.1 INTRODUCTION
Previous chapters of this report quantify water resources available for development and
use. The report also identifies present and future water needs in the basins and identifies future
water use opportunities that could be used to satisfy the identified water demand. In Chapter 8,
development costs of the identified opportunities were presented as well as annual user costs.
Chapter 9 addresses various funding options that project sponsors might choose to pursue.
9.2 FUNDING OF WATER DEVELOPMENT PROJECTS
Water development projects are funded from federal, state,
and private sources. Historically, federal funding has been
responsible for the bulk of the large water development projects in the
western U.S. Several examples of this are large reservoirs located in
Wyoming. Many of these reservoirs were associated with large
irrigation development. Federal funding for water development
projects has become increasingly difficult to secure. Competition
from other needs for limited federal money has been a major reason
large federally financed projects have been on the decline.
However, programs exist within federal agencies for smaller
and more environmental projects. These types of projects might
include habitat development, wetlands, or water quality.
The State of Wyoming has the Water Development Program
that is administered by the Wyoming Water Development
Commission (WWDC) and is subdivided into three programs. Each program has its own financial
account. Account Number 1 is the New Development Account that funds projects that develop new water
or develops a new use for a developed but unused supply. Account Number 2 is the Rehabilitation
Account and deals with rehabilitation and improvement of existing projects. Account Number 3 is the
Storage and Reservoir Development Account. This account is used to fund new dam and reservoir
development.
The State also has the State Clean Water Revolving Fund and the State Drinking Water
Revolving Fund. These two funds are administered by the Wyoming Department of Environmental
Quality (WDEQ), Water Quality Division (WQD). The Clean Water Revolving Fund deals with effluent
and the Drinking Water Revolving Fund funds municipal systems. These two funds are not large
contributors to developing new water but have resulted in significant infrastructure improvements.
The following sections explain some of the more common funding options that are available to
water developers.
9-1

9.0 PROJECT FUNDING
9.2.1 Federal Programs
U.S. Department of Agriculture Rural Development Programs
The U.S. Department of Agriculture (USDA) has its state offices in Casper. The USDA Rural
Development Program administers several grant and loan programs for rural water projects, including:
! Water and waste disposal direct and guaranteed loans for water and waste disposal systems in
rural areas and small towns.
! Water and waste disposal grants covering up to 75 percent of the costs of eligible rural water
and waste disposal projects.
The State through the Water Development Program has partnered with USDA, Rural
Development, to jointly fund development of small community water supply systems throughout the
state.
Additional information regarding the USDA and its programs in Wyoming is available at
http://www.rurdev.usda.gov/wy.
Natural Resources Conservation Service
The Natural Resources Conservation Service (NRCS), formerly the Soil Conservation Service
(SCS) of the USDA, administers a wide variety of programs that provide funding for water-related
projects, including but not limited to the:
! Wildlife Habitat Incentives Program (WHIP) to improve wildlife and fish habitat on private
lands.
! Wetlands Reserve Program to protect, restore, and enhance wetlands on private lands.
! Watershed Program to protect and restore watershed from damage caused by erosion and
flooding and to conserve and develop water resources on a watershed basis.
Information regarding the NRCS and the various funding and assistance programs that the agency
administers is available at http://www.nrcs.usda.gov/programs.
9.2.2 State Programs
Wyoming Water Development Commission
The WWDC, including a 10-member board and a professional staff, administers state funding of
water development programs. The WWDC administers:
! New development program, which focuses on development of unused and/or unappropriated
water.
! Rehabilitation program, which focuses on improving existing water systems.
! New dam and reservoir program, which focuses on developing storage reservoirs to capture
excess streamflows so they can be put to beneficial use during late summer when water is
short.
Water resource planning programs, of which this Framework Water Plan is a component, use
funding from the new development account, the rehabilitation account, or the dam and reservoir account.
9-2

9.0 PROJECT FUNDING
Projects begin with an application from a project sponsor. Applications are due by August 15 of
each year and must include a $1,000 filing fee. The WWDC provides funding for a variety of water
projects based on following prioritized categories:
! Multipurpose programs.
! Water storage projects.
! New water supply projects.
! New supply (conveyance) system projects.
! Hydropower projects.
! Purchase of existing storage projects.
! Watershed improvement projects.
! Recreation projects.
! Drinking Water State Revolving Fund projects.
The WWDC provides a detailed description of application procedures, eligibility criteria, and
related information for use by entities wishing to apply for WWDC water project funding. Detailed
information regarding WWDC funding of Wyoming Water Development Program projects may be found
at http://wwdc.state.wy.us/opcrit.
Wyoming Department of Environmental Quality
Several types of funding programs are available from the WDEQ, including:
! 205j Funds, named for Section 205j of the Federal Clean Water Act, to establish water quality
monitoring programs when existing water quality data are inadequate to assess local water
quality conditions. Information is available at http://deq.state.wy.us/wqd/watershed.
! 319 Funds, named for Section 319 of the Federal Clean Water Act, to implement new nonpoint
source pollution water quality improvement projects or to evaluate the effectiveness of
ongoing projects. Information is available at http://deq.state.wy.us/wqd/watershed.
! State revolving funds for drinking water and clean water projects. The Drinking Water State
Revolving Fund is for drinking water systems, including source, treatment plant, storage tank,
and transmission and distribution line projects. The Clean Water State Revolving Fund is for
sanitary sewer treatment and collection, storm water control, landfill water pollution control,
and other water pollution control projects. Information regarding the funds is available at
http://deq.state.wy.us/wqd/www/srf/index.asp
! Abandoned Mine Land Program’s (AML) mission is to eliminate safety hazards and repair
environmental damage from past mining activities, and to assist communities impacted by
mining. Impact assistance can include development of public facilities. Information
regarding AML’s funding program is available at http://deq.state.wy.us/aml.
State Land and Investment Board
The State Land and Investment Board (SLIB) administers both loan and grant programs that can
be used for project development and rehabilitation, including:
9-3

9.0 PROJECT FUNDING
! Mineral Royalty Grant Program, to alleviate an emergency situation which poses a direct and
immediate threat to health, safety, or welfare or to comply with federal or state mandate or to
provide an essential public service.
! Joint Powers Act Loan Program, to provide loans for planning, construction, acquisition,
improvement, emergency repair, acquisition of land, refinancing of existing debt, and
operation of revenue generating public facilities.
! Impact Mitigation Grants and County Block Grants for Capital Projects, to provide grants for
capital projects under provisions of Chapter 24 Emergency Rules and Regulations State Loan
and Investment Board based on county-wide consensus lists and funding availability for the
benefit of the citizens of the state. Information regarding this program is available at
http://slf-web.state.wy.us/grants/revgrantupdate.aspx
In addition, the SLIB provides the financial oversight and management of the State Revolving
Fund programs. These State Revolving Fund programs are jointly managed by WWDC, WDEQ, and
SLIB. More information on SLIB funding programs is available at http://slf-web.state.wy.us/grants.aspx.
Wyoming Game and Fish Department
The Wyoming Game and Fish Department administers a trust fund to preserve and restore
wildlife habitat and open spaces. The income from the trust fund is used to supply grants to nonprofit and
government groups for specific projects. Information regarding the fund is available at
http://gf.state.wy.us.
9-4

GLOSSARY
acre-foot
aquifer
aquitard
artesian condition
coal bed methane use
community public water supply
system
confined conditions or confined
aquifer
conjunctive use
A unit of measurement for water equal to a volume of water
covering a surface area of one acre to a depth of one foot (equal
to about 326,000 gallons).
A body of earth material saturated with groundwater that can
yield usable quantities of groundwater for human uses; a zone of
freely extractable groundwater in sediment or rock.
A body of earth material (sediment or rock) of intrinsically low
hydraulic conductivity (low permeability) which prevents
significant flow of groundwater, either upward or downward; an
aquitard is less permeable than an aquifer.
When the groundwater level rises above the top of the aquifer in
a well (or borehole, fracture, etc.) due to the presence of a lowpermeability
layer of earth and/or rock above the aquifer.
Water produced in the production of coal bed methane gas via
wells; wells used for the production of coal bed methane require
a permit from the Wyoming Oil and Gas Conservation
Commission.
A U.S. Environmental Protection Agency (USEPA)
designation for a public water supply system that provides water
year-round for at least 15 service connections or at least 25
residents, such as the public water supply system for an
incorporated municipality.
Groundwater occurring in a condition such that a lowpermeability
zone is present above the water-bearing
zone; when the overlying low-permeability zone is penetrated,
the groundwater level rises to the potentiometric surface (equal
pressure level) of the water-bearing zone.
The coordinated use of surface water and groundwater resources.
GA-1

cubic feet per second (cfs)
domestic water use (residential
water use)
drainage area
fully appropriated stream
geohydrology
groundwater
groundwater recharge
groundwater surface
groundwater table
The rate of water flow representing a volume of one cubic foot
of water passing a given point in one second; is equivalent to
flow rates of 7.48 gallons per second, 448.8 gallons per minute,
or 0.02832 cubic meter per second.
Use of water from a single source in three single family
dwellings or less, including noncommercial watering of
lawns and gardens totaling one acre or less in area.
The surface area around a stream as typically plotted and
measured on a horizontal plane (on a map) that has a single
surface water runoff and/or streamflow discharge point.
A body of surface water to which the entire allocation of a state’s
water rights has been distributed among existing water users.
An engineering field concerning the study of subsurface fluid
hydrology.
Water that flows or seeps downward and saturates soil or rock,
supplying springs and wells; the upper level or surface of the
saturated zone is called the water table; water stored
underground in rock crevices and in the pores of geologic
materials that make up the earth's crust; that part of the
subsurface water which is in the zone of saturation; phreatic
water; water found beneath the ground surface in porous rock
strata and soils, as in a spring; generally, all subsurface water, as
distinct from surface water; specifically that part of the
subsurface water in the saturated zone where the water is under
pressure greater than atmospheric pressure.
The flow to groundwater storage of precipitation, infiltration
from streams, and other aboveground sources of water.
The uppermost surface of groundwater as representative of the
uppermost aquifer when under either unconfined or confined
conditions and when the water level is allowed to reach a static
level.
The upper boundary or surface of groundwater where water
pressure is equal to atmospheric pressure, i.e., the stationary
water level in a borehole.
GA-2

head
hydrogeology
hydrology
industrial use
instream bypass
instream flow
irrigation season
irrigation use
karst
leaky conditions or leaky aquifer
miscellaneous use
Differential pressure causing flow in a fluid system, usually
expressed in terms of the height of a liquid column.
The study of water and interrelated geologic materials and
processes.
The study of water.
One type of Wyoming State Engineer’s Office (SEO) “beneficial
use” of water; permitted long-term use of water for the
manufacture of a product or production of oil/gas or other
minerals, including oil field water flood operations, power plant
water supplies, etc.
Federal regulations requiring minimum streamflow rates
immediately below specific water facilities located on U.S.
Forest Service land.
A Wyoming water right that is owned by the State and that
guarantees a minimum rate(s) of flow along specified stream
segments.
The months of April through September, inclusive.
One type of Wyoming State Engineer’s Office (SEO) “beneficial
use” of water; permitted watering of commercially grown crops,
including large scale watering of golf courses, cemeteries,
recreation areas, etc.
An area of irregular limestone in which erosion has produced
fissures, sinkholes, underground streams, and caverns.
A subsurface condition such that groundwater passes through or
"leaks" through low-permeability zones adjacent to an aquifer,
thus recharging groundwater in the receiving aquifer.
One type of Wyoming State Engineer’s Office (SEO) “beneficial
use” of water; any permitted use of water not defined under
another SEO beneficial use definition such as stock water,
pipelines, subdivisions, mine dewatering, mineral/oil exploration
drilling, potable supplies, etc.; includes water use by
subdivisions, mobile home parks, service stations, campgrounds,
churches, schools, temporary drilling activities, etc.
GA-3

municipal use
non-point source pollution
phreatophyte
point source pollution
public water supply system
recharge
recharge area
stock watering use
surface water
One type of Wyoming State Engineer’s Office (SEO) “beneficial
use” of water; permitted use of water in and by the citizens of
incorporated towns and cities.
A contributing factor to water pollution that cannot be traced to a
specific spot; man-made or man-induced alteration of the
chemical, physical, biological, or radiological integrity of water,
originating from any source other than a point source; pollution
which comes from diffuse sources such as urban and agricultural
runoff, including storm water runoff containing excess farm and
lawn nutrients that move through the soil into the groundwater or
enter local surface water.
A deep-rooted plant that obtains water from a permanent
groundwater supply.
Any discernible, confined, or discrete conveyance from which
pollutants are or may be discharged, including, but not limited
to, any pipe, ditch, channel, tunnel, conduit, well, container,
rolling stock, concentrated animal feeding operation, vessel, or
other floating craft; a stationary location or fixed facility from
which pollutants are discharged or emitted into groundwater or
surface water.
A U.S. Environmental Protection Agency (USEPA) designation
for a water supply system that provides potable water for at least
15 service connections or 25 people per day for a minimum of 60
days per year.
Water flow into an area, aquifer, or well, typically from a surface
water source to groundwater in an aquifer.
The land area(s) over which recharge of an aquifer, typically by
infiltration of surface water, occurs.
One type of Wyoming State Engineer’s Office (SEO) “beneficial
use” of water; permitted water appropriation including normal
livestock use at up to four tanks and within one mile of the well
or spring source of water supply.
Water on the surface of the earth; an open body of water, such as
a river, stream, or lake.
GA-4

till
transmissivity
unconfined condition
waste (irrigation)
water level
water table
water year
Glacial drift consisting of an unassorted mixture of clay, sand,
gravel, and boulders.
The rate of groundwater flow in an aquifer in gallons per minute
of flow through a one foot wide vertical section of the entire
aquifer thickness under a hydraulic gradient of one foot.
Groundwater present in an aquifer without an overlying lowpermeability
bed or upward water pressure.
Water which is diverted from a river in a canal or ditch for
irrigation use but which, because of conveyance system
limitations, is not diverted from the canal or ditch to irrigate land
and is discharged to a drain or stream via wasteways along the
irrigation canal.
The water surface elevation or stage of the free surface of a body
of water above or below any datum or the surface of standing
water in a well, usually indicative of the position of the
groundwater surface (the "water table") or other potentiometric
groundwater surface.
An archaic term from the 1800s that is now superseded in
modern technical use by the term "groundwater surface;" use of
the term "water table" should be discontinued in technical
documents.
October 1 - September 30 (e.g., Water Year 2005 begins October
1, 2004, and ends September 30, 2005).
GA-5

ACRONYM LIST
AF or AC-FT
ASCE
ASR
BAG
BCF
BLM
BTU
CBM
CBMCC
cfs
CIR
CRP
CU
CU w
DOI
EA
EIS
ET
ESA
FERC
FONSI
ft
gal
gpcpd
gpd
gpm
GUI
GW
IWR
MCF
MCL
MW
NASS
NEPA
NPDC
NPDES
NRCS
NWI
Acre-feet
American Society of Civil Engineers
Artificial aquifer Storage and Recovery
Basin Advisory Group
Billion cubic feet
U.S. Bureau of Land Management
British Thermal Unit
Coal bed methane
Coal Bed Methane Coordination Coalition
Cubic feet per second
Consumptive Irrigation Requirement
Conservation Reserve Program
Consumptive Use
Consumptive use of irrigation water, usually in units of inches per acre per
month
United States Department of the Interior
Environmental Assessment
Environmental Impact Statement
Evapotranspiration
Endangered Species Act
Federal Energy Regulatory Commission
Finding of No Significant Impact
Feet
Gallons
Gallons per capita per day
Gallons per day
gallons per minute
Graphical User Interface
Ground water
Irrigation Water Requirements
Million cubic feet
Maximum contaminant level
Megawatts
National Agricultural Statistics Service
National Environmental Policy Act
North Platte Decree Committee
National Pollutant Discharge Elimination System
Natural Resources Conservation Service
National Wetlands Inventory
GA-6

OGCC
PAM
PIA
PRRIP
PRSB
SCS
SEO
SLIP
SMP
SW
SWWRC
TDS
TMDL
USBR
USCB
USCOE
USDA
USEPA
USFS
USFWS
USGS
WBHB
WDAI
WDEQ
WGF
WHIP
WQD
WRDS
WRIR
WRP
Oil and Gas Conservation Commission (State of Wyoming)
Polyacrylamide
Potential Irrigable Acres
Platte River Recovery and Implementation Program
Powder River Structural Basin
Spill Conservation Service
Wyoming State Engineer’s Office
State Land and Investment Board
State Management Plan (State of Wyoming)
Surface water
States West Water Resources Corporation
Total dissolved solids (in units of milligrams per liter, mg/L)
Total minimum daily load (of pollutants in a water body)
U.S. Bureau of Reclamation
U.S. Census Bureau
U.S. Army Corps of Engineers
U.S. Department of Agriculture
U.S. Environmental Protection Agency
U.S. Forest Service
U.S. Fish and Wildlife Service
U.S. Geological Survey
Wind/Big Horn River Basin
Wyoming Department of Administration and Information
Wyoming Department of Environmental Quality
Wyoming Game and Fish Department
Wildlife Habitat and Incentives Program
Wyoming Dept. of Environmental Quality, Water Quality Division
Water Resource Data System
Wind River Indian Reservation
Wetlands Reserve Program
GA-7

INDEX
Agricultural, 3-1, 3-3, 3-9, 3-21, 3-25, 3-26, 3-27, 3-30, 4-
5, 4-9, 4-10, 5-1, 5-3, 5-4, 6-2, 6-5, 6-6, 7-3, 7-15, 7-16,
7-17, 8-3, 8-4, 8-5, 8-8, 8-9, 8-12, 8-15, 8-18, 8-27, 8-
29, 8-30, 8-33, 8-34, 8-35, 8-45, 8-46, 8-47, 8-48, 8-50,
8-51, 8-53
Agricultural Need, 8-3, 8-4, 8-5, 8-8, 8-9, 8-18, 8-27, 8-35,
8-45, 8-50, 8-51
Agricultural Water Conservation, 7-16
Agricultural Water Use, 5-1, 7-16, 8-3
Agriculture, 3-7, 3-8, 3-9, 3-10, 3-12, 3-23, 3-26, 3-30, 5-3,
5-23, 6-1, 6-2, 6-3, 6-7, 6-27, 6-28, 6-29, 6-30, 7-16, 8-
3, 8-12, 8-15, 8-30, 8-45, 9-2
Alluvial, 4-6, 4-8, 4-9, 4-10, 7-11, 7-12, 7-13, 7-14, 8-8, 8-
17, 8-49, 8-52, 8-53
Angler Days, 5-16
Annual Flow, 4-3, 7-4
Annual Streamflow, 4-3
Aquifer, 4-5, 4-6, 4-7, 4-8, 4-9, 4-10, 7-9, 7-10, 7-11, 7-12,
7-13, 7-14, 8-4, 8-8, 8-17, 8-20, 8-30, 8-44, 8-49, 8-52,
8-53, 8-59, 8-60
Aquifer Classification, 4-5
Aquifer Sensitivity, 4-10
Area, 3-1, 3-2, 3-3, 3-4, 3-6, 3-9, 3-11, 3-12, 3-15, 3-16, 3-
18, 3-19, 3-20, 4-2, 4-4, 4-5, 4-6, 5-4, 5-5, 5-8, 5-10, 5-
12, 5-13, 5-15, 5-21, 5-23, 6-2, 6-6, 6-7, 6-8, 6-10, 6-13,
6-15, 6-16, 6-18, 6-25, 6-27, 6-28, 7-2, 7-5, 7-6, 7-9, 7-
11, 7-14, 8-1, 8-4, 8-16, 8-18, 8-30, 8-35, 8-44, 8-46, 8-
48, 8-49, 8-50, 8-52, 8-55, 8-59, 8-60
availability, 4-1, 6-17, 6-22, 7-1, 7-4, 7-9, 7-12, 7-13, 7-14,
8-3, 8-17, 8-31, 8-49, 9-4
Availability, 1-1
Available Flow, 7-4, 7-6, 7-7, 7-8, 8-4, 8-8, 8-17, 8-18, 8-
34, 8-35, 8-44, 8-45, 8-50
Average Annual Streamflow, 4-3, 7-5, 7-9
Basin Compact, 3-12, 3-15
Basin Plan, 1-1, 1-3, 3-5, 4-2, 4-4, 4-5, 4-10, 5-1, 5-2, 5-3,
5-4, 5-5, 5-6, 5-7, 5-9, 5-10, 5-11, 5-12, 5-13, 5-15, 5-
16, 5-19, 5-21, 6-3, 6-4, 6-6, 6-7, 6-8, 6-10, 6-11, 6-15,
6-16, 6-17, 6-18, 6-22, 6-28, 6-30, 7-1, 7-2, 7-3, 7-4, 7-
5, 7-6, 7-7, 7-8, 7-9, 7-12, 7-14, 7-15, 7-18, 8-1, 8-2, 8-
4, 8-5, 8-8, 8-9, 8-12, 8-18, 8-19, 8-22, 8-23, 8-27, 8-29,
8-35, 8-36, 8-45, 8-50, 8-51, 8-56
Basin Plan Summary, 1-3
Bear River, 1-3, 3-3, 3-14, 3-15, 4-2, 4-4, 5-4, 5-5, 5-7, 5-
11, 5-12, 5-16, 5-19, 6-12, 6-13, 6-21, 6-23, 6-24, 6-25,
6-28, 6-29, 6-30, 7-2, 7-5, 7-6, 7-8, 7-9, 7-12, 7-14, 8-1,
8-3, 8-4, 8-5, 8-6, 8-7, 8-8
Bear River Compact, 3-14, 8-4, 8-8
Belle Fourche River Compact, 3-15, 8-17, 8-18
Boating, 5-15, 5-16
Buffalo Bill Dam, 3-24
Bull Lake Enlargement, 8-52, 8-55, 8-57, 8-58
Bureau of Land Management, 3-2, 5-12, 6-18
Census Data, 3-5, 3-9, 3-11
Chemical Plant, 6-20, 6-21
Chloride, 3-27, 3-28, 4-9
Clean Water Act, 3-23, 3-27, 3-29, 3-30, 9-3
Climate, 3-4, 3-30, 4-1, 4-5, 4-10, 5-8, 6-6, 7-11, 7-16
Coal, 3-10, 3-11, 3-13, 4-6, 4-7, 4-10, 5-11, 5-12, 5-13, 6-
12, 6-13, 6-14, 6-15, 6-16, 6-17, 6-18, 7-12, 8-17, 8-42
Coal Mining, 3-10, 5-12, 6-16
Coalbed Methane, 3-27, 4-9, 5-12, 6-17, 7-12, 7-14, 8-27,
8-30, 8-44
Colorado River Basin, 3-15, 3-17, 8-8, 8-60
Colorado River Compact, 3-15, 3-17, 8-8
Compact, 1-2, 3-14, 3-15, 3-16, 5-5, 7-1, 7-4, 7-5, 7-9, 8-4,
8-8, 8-17, 8-26, 8-34, 8-45, 8-50, 8-56
Conservation, 1-2, 3-24, 4-10, 5-3, 5-12, 5-19, 5-21, 6-6, 6-
27, 6-30, 7-15, 7-16, 7-17, 7-18, 8-10, 8-30, 8-33, 8-38,
9-2
Construction, 1-2, 3-10, 3-15, 3-23, 5-13, 6-12, 6-15, 6-18,
7-1, 7-16, 7-17, 8-2, 8-5, 8-58, 8-59, 9-4
Consumptive Use, 3-15, 5-1, 5-2, 5-3, 5-5, 5-7, 5-8, 5-9, 5-
10, 5-17, 5-18, 5-21, 5-23, 6-8, 6-11, 6-17, 6-20, 6-21,
6-28, 7-5, 8-4, 8-8, 8-18, 8-34, 8-35, 8-45, 8-50
Consumptive Water Demand, 6-29
Continental Divide, 3-1, 3-3
Contracts and Agreements, 3-14, 3-22
County, 3-1, 3-2, 3-4, 3-5, 3-6, 3-8, 3-9, 3-10, 3-21, 4-10,
5-13, 5-16, 5-17, 5-18, 5-23, 6-2, 6-8, 6-9, 6-12, 6-16, 6-
18, 7-12, 7-13, 8-22, 8-30, 8-31, 8-52, 8-60, 9-4
Court Decree, 3-12, 3-14, 3-17
Crop, 3-4, 5-1, 5-2, 5-3, 5-4, 5-5, 5-7, 5-8, 6-3, 6-6, 7-13, 7-
17, 7-18, 8-4, 8-33
Crop Type, 5-1, 5-3, 5-4, 5-5, 5-8
Crude Oil, 3-10, 6-16
Current Water Use, 5-11, 5-13, 5-15, 5-20
Direct Wildlife Consumption, 5-19, 5-21, 6-28
Diversion, 3-13, 3-14, 3-16, 3-17, 3-18, 3-19, 3-20, 3-21, 4-
3, 5-1, 5-5, 5-6, 5-7, 5-8, 6-4, 6-5, 6-6, 7-2, 7-3, 7-4, 7-
10, 8-3, 8-4, 8-16, 8-31, 8-32, 8-52
Diversion Record, 5-5, 5-6, 7-3, 8-4
Domestic, 3-11, 3-16, 3-23, 3-25, 3-26, 3-27, 4-7, 4-10, 5-
11, 5-12, 6-8, 6-10, 6-11, 6-18, 6-19, 6-20, 6-22, 6-29,
7-5, 7-9, 8-8, 8-17, 8-27, 8-30, 8-44, 8-45, 8-46, 8-47, 8-
48, 8-49, 8-50, 8-60
Domestic Water Use, 3-11, 5-11, 5-12, 6-10, 6-11
Domestic Well, 4-10, 5-11
Drainage System, 3-3
Drinking Water Standard, 3-28
Drought Response Planning, 8-29, 8-32, 8-33
Economic and Water Use Sectors, 3-8
Economic Base Methodology, 6-10
Economics, 1-3, 6-10, 8-6, 8-49
Effective Precipitation, 3-4, 5-1, 5-2, 5-8
Electric Power Generating Facilities, 3-10, 3-11
Electric Power Generation, 5-12, 5-13, 6-12, 6-13, 6-15, 6-
17, 6-19, 6-21
Employment, 3-7, 3-8, 3-9, 3-10, 3-30, 6-18, 6-20, 6-22
Employment and Labor Force Participation, 3-7
Endangered Species Act, 3-24, 3-29, 5-21
Environmental, 1-2, 3-8, 3-12, 3-20, 3-21, 3-23, 3-25, 3-30,
4-3, 4-4, 4-10, 5-1, 5-19, 5-20, 5-21, 6-26, 6-27, 7-1, 7-
16, 7-17, 8-2, 8-3, 8-5, 8-10, 8-20, 8-21, 8-22, 8-26, 8-
31, 8-37, 8-38, 8-39, 8-40, 8-41, 8-42, 8-45, 8-46, 8-47,
8-48, 8-49, 8-53, 8-54, 9-1, 9-3
Environmental Quality Act, 3-25, 3-30, 4-4

Environmental Use, 3-12, 5-1, 5-19, 5-21, 6-26, 6-27, 7-17,
8-2
Environmental Water Use, 3-8, 3-12, 5-20, 6-26
Environmental/Recreational Benefits, 8-2
Evapotranspiration, 4-1, 5-1, 5-2, 5-3, 5-23, 7-12, 8-16
Federal Environmental Laws, 3-29
Federal Funding, 1-2
Federal Land, 3-22, 3-29, 5-21
Federal Law, 3-12, 8-2
Federal Program, 1-2, 3-29, 6-27, 9-2
Financial Feasibility, 8-2, 8-10, 8-20, 8-21, 8-37, 8-38, 8-
39, 8-40, 8-41, 8-42, 8-46, 8-47, 8-53
Fishing, 3-12, 5-15, 5-16, 5-17, 5-18, 6-23, 6-24, 6-25, 7-18
Flow, 3-3, 3-14, 3-15, 3-16, 3-17, 3-18, 3-19, 3-20, 3-21, 3-
23, 3-24, 4-3, 4-4, 5-6, 5-7, 5-17, 5-19, 5-20, 5-21, 6-4,
6-26, 6-27, 7-1, 7-3, 7-4, 7-6, 7-7, 7-9, 7-10, 7-12, 7-17,
8-34, 8-45, 8-49, 8-50
Fontenelle Reservoir, 3-22, 3-23, 6-25, 7-8
Forage Crops, 3-4, 5-4, 5-5
Forest Service, 3-2, 8-29
Framework Scoring Matrix, 8-1, 8-2, 8-3, 8-6, 8-7, 8-13, 8-
15, 8-23, 8-24, 8-26, 8-56, 8-57
Frost-Free Days, 3-30
Future Needs, 1-2, 3-22, 6-11, 8-27, 8-28
Future Water Use Opportunities, 8-1, 8-4, 8-5, 8-8, 8-9, 8-
17, 8-19, 8-27, 8-29, 8-30, 8-32, 8-34, 8-36, 8-44, 8-45,
8-50, 8-51, 9-1
Glendo Reservoir, 3-18, 3-19, 3-24, 8-29, 8-33
Golf Course, 3-12, 5-17, 5-18, 5-19, 6-24
Golfing, 3-12, 5-15, 5-17, 5-18, 6-22
Great Basin, 3-1, 3-3
Green River, 1-3, 3-22, 4-2, 4-3, 5-4, 5-5, 5-7, 5-11, 5-12,
5-13, 5-15, 5-16, 5-21, 6-12, 6-13, 6-15, 6-16, 6-18, 6-
19, 6-20, 6-21, 6-25, 6-27, 6-28, 7-5, 7-6, 7-8, 7-9, 7-12,
7-14, 8-8, 8-9, 8-10, 8-11, 8-12, 8-13, 8-14, 8-16, 8-17,
8-32, 8-60
groundwater, 7-10
Groundwater, 3-3, 3-10, 3-14, 3-15, 3-16, 3-18, 3-20, 3-22,
3-25, 3-26, 3-27, 3-29, 4-1, 4-4, 4-5, 4-6, 4-7, 4-8, 4-9,
4-10, 5-2, 5-3, 5-5, 5-7, 5-8, 5-10, 5-11, 5-12, 5-13, 6-
11, 6-12, 6-14, 6-16, 6-17, 6-18, 6-30, 7-1, 7-9, 7-10, 7-
11, 7-12, 7-13, 7-14, 7-15, 7-17, 7-18, 8-4, 8-8, 8-10, 8-
11, 8-12, 8-16, 8-17, 8-20, 8-21, 8-27, 8-29, 8-30, 8-37,
8-38, 8-39, 8-40, 8-41, 8-42, 8-44, 8-46, 8-49, 8-50, 8-
53, 8-59, 8-60
Groundwater Associated with Energy Development, 4-10
Groundwater Availability, 7-13, 7-14
Groundwater Control Area, 7-12
Groundwater Development, 3-16, 4-5, 4-7, 7-10, 7-13, 8-4,
8-8, 8-10, 8-11, 8-16, 8-20, 8-21, 8-27, 8-30, 8-37, 8-38,
8-39, 8-40, 8-41, 8-42, 8-44, 8-49, 8-53, 8-59
Groundwater Diversion Rate, 7-10
Groundwater Permit, 3-20, 7-15
Groundwater Quality, 3-26, 3-27, 3-29, 4-5, 4-6, 4-7, 4-9,
7-13, 7-14, 8-49
Groundwater Recharge, 4-1, 7-11, 7-12, 7-17, 8-12, 8-16,
8-17
Groundwater Resource, 4-4, 8-17
High Savery, 3-23, 6-27
Historic Population Growth, 3-4
Historic Site, 5-18, 5-23
Historical Aquifer Performance, 4-9
Hydroelectric Plant, 6-21
Hydrologic Cycle, 4-1, 4-4
Impaired Stream, 3-29, 4-4, 8-52
Increasing Runoff from National Forests, 8-29, 8-33
Industrial, 3-3, 3-10, 3-12, 3-22, 3-25, 3-26, 5-1, 5-12, 5-
13, 5-21, 6-3, 6-11, 6-15, 6-17, 6-18, 6-20, 6-21, 6-22,
6-29, 6-30, 7-9, 7-15, 7-17, 8-15, 8-27, 8-30, 8-34, 8-41,
8-45, 8-46, 8-47, 8-48, 8-59
Industrial Use, 3-12, 5-1, 5-13, 6-3, 6-20, 6-21, 6-29, 6-30,
7-9, 8-15, 8-34
Industrial Water Conservation, 7-17
Industrial Water Demand Projections, 6-22
Industrial Water Use, 5-13, 6-3, 6-11, 6-21, 6-22, 7-17
Industry, 3-1, 3-7, 3-9, 3-10, 3-26, 5-12, 6-1, 6-3, 6-16, 6-
17, 6-19, 6-20, 6-21, 6-29, 6-30, 7-12, 7-16, 7-17, 8-17,
8-30, 8-33
Instream Flow, 3-12, 3-14, 3-21, 3-22, 3-24, 5-15, 5-19, 5-
20, 5-21, 6-26, 7-4, 8-47, 8-52
International Treaty, 3-14, 3-17
Interstate Compact, 3-13, 3-14, 5-20, 7-5, 8-17
Irrigable Land, 6-6, 6-7
Irrigated, 3-9, 3-10, 3-12, 3-18, 5-1, 5-2, 5-3, 5-4, 5-5, 5-6,
5-7, 5-8, 5-9, 6-1, 6-2, 6-3, 6-4, 6-5, 6-6, 6-7, 6-28, 7-
11, 7-17, 8-3, 8-4, 8-5, 8-7, 8-8, 8-9, 8-13, 8-18, 8-24, 8-
35, 8-43, 8-44, 8-45, 8-50, 8-51, 8-57
Irrigated Acreage, 3-18, 5-1, 5-2, 5-3, 5-4, 5-5, 5-8, 6-1, 6-
2, 6-3, 6-4, 8-3, 8-44, 8-45
Irrigated Crop, 3-10, 5-3, 5-4, 5-5, 5-8
Irrigated Crop Distribution, 5-3, 5-5
Irrigated Land, 3-9, 5-2, 5-3, 5-4, 5-9, 6-2, 6-3, 6-6, 7-11,
8-5, 8-7, 8-9, 8-13, 8-18, 8-24, 8-35, 8-43, 8-45, 8-51, 8-
57
Irrigation, 1-2, 3-4, 3-9, 3-10, 3-12, 3-13, 3-17, 3-18, 3-19,
3-20, 3-21, 3-23, 3-24, 3-25, 3-27, 4-3, 4-4, 4-5, 4-9, 5-
1, 5-2, 5-3, 5-5, 5-6, 5-7, 5-8, 5-9, 5-11, 5-15, 5-18, 5-
19, 5-21, 5-23, 6-2, 6-3, 6-4, 6-5, 6-6, 6-7, 6-24, 6-26, 6-
28, 6-30, 7-10, 7-12, 7-15, 7-16, 7-17, 7-18, 8-2, 8-3, 8-
5, 8-26, 8-27, 8-29, 8-30, 8-31, 8-45, 8-46, 8-47, 8-48,
8-52, 8-53, 8-54, 9-1
Irrigation Water Requirement, 5-1, 5-2, 5-3, 5-7, 5-8, 5-9,
5-23, 8-3
Irrigation Well, 3-20, 5-7
Kirby Area Water Supply, 8-55, 8-59, 8-60
Labor Force, 3-7, 3-8
Land Area, 3-1, 3-3, 6-5, 6-6
Land Commission, 3-2
Land Ownership, 3-1, 3-2, 3-3, 8-3, 8-7, 8-14, 8-25, 8-49,
8-57
Legal/Institutional Concern, 8-2
Legally Available Flow, 6-30, 7-6, 7-7, 7-8, 8-4, 8-45
Limestone, 4-5, 4-6, 4-8, 7-10, 7-14, 7-15
Livestock, 3-1, 3-9, 3-10, 3-27, 4-9, 5-1, 5-5, 5-10, 6-1, 6-
2, 6-3, 6-7, 6-8
Livestock Industry, 3-1, 3-9, 3-10
Livestock Production, 3-9, 3-10, 5-5, 6-1, 6-2, 6-3
Major Aquifer, 4-5, 4-6, 4-7, 7-10, 7-13, 7-14, 8-4, 8-59
Major Aquitard, 4-5, 4-7, 4-9
Marginal Aquifer, 4-7
Mineral Sector, 3-8
Minimum Releases and Reservoir Bypasses, 6-27
Mining, 3-7, 3-10, 3-13, 5-12, 5-13, 6-15, 6-16, 6-19, 6-20,
6-21, 9-3

Minor Aquifer, 4-7
Missouri River Basin, 8-19
Model, 6-6, 7-1, 7-2, 7-3, 7-7
Modeling, 5-3, 6-6, 6-10, 7-2, 7-3, 7-4, 8-3
Multipurpose Flood Control Programs, 8-29, 8-33
Municipal, 3-3, 3-8, 3-11, 3-12, 3-22, 3-23, 3-25, 3-26, 4-9,
5-1, 5-10, 5-11, 5-12, 5-15, 5-18, 5-21, 6-3, 6-8, 6-10, 6-
11, 6-22, 6-29, 7-5, 7-9, 7-12, 7-15, 7-17, 8-8, 8-15, 8-
17, 8-27, 8-29, 8-30, 8-31, 8-33, 8-34, 8-44, 8-45, 8-46,
8-47, 8-48, 8-49, 8-50, 8-52, 8-53, 8-59, 8-60, 9-1
Municipal and Domestic Use, 5-1, 5-11, 6-8, 6-10
Municipal and Domestic Use Projection, 6-8, 6-10
Municipal Water Conservation, 7-17
Municipal Water Use, 5-10, 7-17
Municipal Well, 5-11
Municipality, 1-2, 3-11, 3-20, 5-10, 5-18, 5-20, 7-12, 7-16,
7-17, 8-15, 8-30, 8-31, 8-33
National Environmental Policy Act, 3-23, 3-30
National Forest, 3-21, 5-19, 6-25, 8-33, 8-43, 8-48
National Monument, 5-19
National Park, 3-1, 3-2, 3-22, 4-2, 5-18, 5-19, 5-23, 7-5, 7-
9, 8-47
National Park Service, 3-2, 5-19
National Wetlands Inventory, 5-22
Natural Gas, 3-10, 6-12, 6-13, 6-14, 6-15, 6-17, 6-18
Natural Gas Production, 6-17, 6-18
Northeast Wyoming River, 5-5, 5-13, 5-19, 5-21, 6-11,
6-12, 6-13, 6-15, 6-16, 6-17, 6-18, 7-6, 7-9, 8-17, 8-18,
8-24, 8-25, 8-26, 8-27
Northeast Wyoming Rivers, 1-3
oil, 3-10, 4-9, 4-10, 5-12, 6-16, 6-29, 6-30
Oil, 4-10, 5-12, 6-16
Palisades Reservoir Contract, 3-24
Physical Availability, 4-1, 7-1
Physically Available Flow, 7-6, 7-7, 7-8, 8-4, 8-8, 8-17, 8-
27, 8-34, 8-44, 8-45, 8-50
Physiography, 3-3
Platte River, 1-3, 3-4, 3-12, 3-17, 3-18, 3-19, 3-20, 3-23, 3-
24, 4-2, 4-3, 5-4, 5-7, 5-11, 5-12, 5-13, 5-16, 5-17, 6-2,
6-11, 6-12, 6-13, 6-15, 6-16, 6-18, 6-20, 6-23, 6-24, 6-
27, 6-30, 7-2, 7-5, 7-6, 7-9, 7-12, 7-13, 7-14, 8-27, 8-28,
8-29, 8-30, 8-31, 8-32, 8-34, 8-56
Platte River Recovery Implementation Program, 3-20, 3-
23, 7-13, 8-27
Population, 3-1, 3-4, 3-5, 3-6, 3-7, 3-8, 3-11, 3-12, 5-11, 5-
17, 6-2, 6-8, 6-9, 6-10, 6-22, 6-23, 6-26, 7-17, 8-2
Population Characteristics, 3-8
Population Estimate, 3-5, 6-8
Population Projection, 6-8, 6-9, 6-10, 6-22
Potential Groundwater Development, 8-4, 8-30, 8-44
Potential Reservoir Site, 8-22
Power Production, 5-13, 5-21, 6-12, 6-13, 6-15, 6-21
Precipitation, 3-4, 4-1, 4-3, 4-5, 5-2, 5-5, 5-8, 7-12, 8-17
Presentation Tool, 1-1, 2-1
Project Funding, 1-1, 7-13, 9-3
Project Planning, 1-2, 8-1
Projected Annual Growth Rate, 6-23
Projected Population, 6-8, 6-9
Projection, 6-1, 6-10, 7-9
Reach Gain/Loss, 7-4
Recharge, 4-4, 4-5, 4-8, 4-9, 4-10, 7-11, 7-12, 7-13, 7-14,
8-4, 8-12, 8-16, 8-53, 8-59, 8-60
Recommendations for Opportunities, 8-48
Recommendations for Storage Opportunities, 8-15, 8-23, 8-
43, 8-56, 8-58
Recreation, 3-2, 3-8, 3-12, 3-23, 3-26, 5-15, 5-18, 5-21, 5-
23, 6-2, 6-22, 6-23, 6-27, 7-16, 8-3, 8-5, 8-10, 8-20, 8-
21, 8-22, 8-26, 8-37, 8-38, 8-39, 8-40, 8-41, 8-42, 8-46,
8-47, 8-48, 8-53, 8-54, 8-57, 8-59, 9-3
Recreational, 3-12, 3-21, 3-25, 3-26, 5-1, 5-15, 5-17, 5-18,
5-19, 5-21, 6-8, 6-22, 6-23, 6-24, 6-25, 6-26, 6-27, 6-28,
6-29, 7-17, 8-2, 8-22, 8-24, 8-27, 8-29, 8-33, 8-45, 8-46,
8-47, 8-48
Recreational and Environmental Water Conservation, 7-17
Recreational Demand, 6-22
Regionalization of Public Water Supply Systems, 8-29, 8-
31
Reservoir, 3-15, 3-17, 3-18, 3-19, 3-20, 3-22, 3-23, 3-24, 3-
25, 4-3, 5-4, 5-6, 5-19, 5-20, 5-21, 5-23, 6-12, 6-13, 6-
15, 6-16, 6-25, 6-26, 6-27, 6-30, 7-4, 7-5, 7-9, 7-11, 7-
12, 7-13, 8-3, 8-5, 8-6, 8-10, 8-11, 8-12, 8-13, 8-14, 8-
15, 8-16, 8-20, 8-21, 8-22, 8-23, 8-24, 8-26, 8-29, 8-31,
8-32, 8-37, 8-38, 8-39, 8-40, 8-41, 8-43, 8-44, 8-46, 8-
47, 8-48, 8-52, 8-54, 8-55, 8-56, 8-57, 8-58, 8-59, 8-60,
9-1, 9-2
Resource, 1-2, 3-16, 3-22, 3-26, 4-1, 4-3, 4-4, 5-17, 6-8, 6-
17, 6-20, 6-25, 7-3, 7-10, 7-11, 7-17, 8-17, 8-31, 8-49,
8-55, 9-2
Reuse, 7-15, 7-17, 8-29, 8-31, 8-52
Reuse Alternative, 8-29, 8-31
River Basin Planning Area, 3-1, 3-3, 3-5, 4-2, 5-10, 5-11,
5-12, 5-13, 5-16, 5-17, 5-21, 5-23, 6-6, 6-8, 6-9, 6-11, 6-
16, 6-22, 6-23, 6-24, 6-25, 6-26, 6-27, 6-28, 6-30, 7-2,
7-3, 7-5, 7-6, 7-15, 7-18, 8-1, 8-3
Roxana Decree, 3-21
Runoff, 3-3, 4-3, 4-4, 5-7, 7-16, 7-17, 8-31, 8-33, 8-46, 8-
47
Scoring Matrix, 8-3, 8-6, 8-26, 8-55
Screening Criteria, 8-1
Seasonal Consumptive Irrigation, 3-4
Selenium, 3-28
Setting, 1-1, 3-1, 5-17
Short List, 8-1, 8-2, 8-5, 8-9, 8-10, 8-12, 8-19, 8-20, 8-21,
8-22, 8-23, 8-27, 8-29, 8-36, 8-37, 8-38, 8-39, 8-40, 8-
41, 8-42, 8-43, 8-44, 8-45, 8-46, 8-47, 8-48, 8-51, 8-52,
8-53, 8-55, 8-56, 8-59
Short List of Future Water Use Opportunities, 8-2, 8-9, 8-
19, 8-29, 8-36, 8-51
Ski Area, 5-17
Skiing and Winter Sports, 5-15, 5-17
Snake River Compact, 3-16, 3-24, 8-45
Snake/Salt River, 1-3, 3-7, 3-12, 3-24, 4-2, 5-4, 5-7, 5-11,
5-12, 5-13, 5-15, 5-16, 5-17, 5-18, 5-19, 5-23, 6-2, 6-11,
6-12, 6-13, 6-23, 6-24, 6-27, 7-5, 7-7, 7-8, 7-9, 7-12, 7-
14, 8-44, 8-45, 8-50
Snow Fence, 8-29, 8-31
Soda Ash, 5-12, 6-18, 6-19, 6-20, 6-21
Source of Supply, 5-3, 5-10
Spreadsheet Models, 7-1, 7-2, 7-4
State Land and Investment Board, 9-3
State Park, 3-12, 5-15, 5-18, 5-23
State Program, 9-2
State Water Quality Assessment Report, 3-29

Storage, 1-2, 3-15, 3-16, 3-17, 3-18, 3-19, 3-22, 3-24, 3-25,
3-29, 4-3, 5-20, 5-21, 6-26, 6-27, 7-4, 7-10, 7-11, 7-13,
7-16, 7-17, 8-2, 8-4, 8-5, 8-6, 8-7, 8-9, 8-11, 8-12, 8-13,
8-15, 8-16, 8-17, 8-19, 8-20, 8-22, 8-23, 8-24, 8-25, 8-
26, 8-27, 8-29, 8-31, 8-32, 8-33, 8-36, 8-43, 8-44, 8-48,
8-49, 8-52, 8-53, 8-54, 8-55, 8-56, 8-57, 8-58, 8-59, 8-
60, 9-1, 9-2, 9-3
Storage Opportunities, 8-24, 8-25, 8-26, 8-52, 8-53, 8-58,
8-59
Stream Gage Data, 7-3
Streamflow Gage, 4-3
Study Period, 7-1, 7-2, 7-3, 7-5
Supplemental Studies, 8-12, 8-13, 8-22, 8-55
Supply Estimate, 6-24, 7-4, 7-6, 7-9
Surface Water, 3-1, 3-2, 3-10, 3-19, 3-20, 3-21, 3-22, 3-25,
3-27, 3-29, 4-1, 4-2, 4-4, 4-9, 5-3, 5-5, 5-7, 5-8, 5-10, 5-
11, 5-12, 5-13, 6-6, 6-11, 6-12, 6-14, 6-15, 6-16, 6-30,
7-1, 7-2, 7-3, 7-6, 7-9, 7-10, 7-11, 7-12, 7-13, 7-14, 8-
27, 8-29, 8-50, 8-59
Surface Water Classification, 3-25
Surface Water Model, 7-1, 7-2
Surface Water Quality, 3-25, 3-29, 4-4
Surface Water Resources, 6-16, 7-13, 8-27
Theoretical Irrigation Water Requirement, 5-7, 5-8
Theoretical Maximum Diversion Requirement, 5-7, 5-8
Threatened and Endangered Species, 5-21
Topography, 3-3, 3-4, 7-16
Total Maximum Daily Loads, 3-29
Total Water Supply, 1-1, 5-8
Tourism, 3-8, 3-12, 5-15, 5-18, 6-22, 6-23, 6-26, 8-33
Transbasin Diversions, 3-23, 8-9, 8-29, 8-31, 8-32
Transportation, 3-1, 3-10, 6-18, 6-19, 6-20
Travel, 3-8, 3-12, 6-22
Tribal Futures, 5-2, 5-3, 5-9, 6-2, 6-3, 6-4, 6-5, 6-6, 6-7, 7-
7, 7-8
U.S. Environmental Protection Agency, 3-27
Unemployment, 3-7, 3-8
Upper Niobrara River Compact, 3-16
Uranium, 3-10, 3-28, 5-12, 6-15, 6-16
Use, 1-1, 1-2, 2-1, 3-3, 3-10, 3-12, 3-13, 3-14, 3-15, 3-16,
3-20, 3-21, 3-22, 3-24, 3-25, 3-26, 3-27, 3-29, 4-1, 4-3,
4-4, 4-5, 4-7, 4-9, 5-1, 5-2, 5-6, 5-7, 5-8, 5-10, 5-11, 5-
12, 5-13, 5-15, 5-16, 5-18, 5-19, 5-20, 5-21, 5-23, 6-3,
6-5, 6-7, 6-8, 6-10, 6-11, 6-12, 6-14, 6-15, 6-16, 6-17, 6-
18, 6-19, 6-20, 6-21, 6-22, 6-25, 6-28, 6-29, 6-30, 7-1,
7-2, 7-3, 7-4, 7-5, 7-9, 7-10, 7-11, 7-13, 7-14, 7-15, 7-
16, 7-17, 7-18, 8-1, 8-2, 8-3, 8-5, 8-7, 8-8, 8-12, 8-14, 8-
17, 8-25, 8-26, 8-27, 8-29, 8-30, 8-31, 8-33, 8-36, 8-44,
8-45, 8-47, 8-49, 8-50, 8-52, 8-53, 8-55, 8-57, 8-60, 9-1,
9-2, 9-3
Utilities, 3-10, 6-18
Warehousing, 3-10
Water Availability, 3-15, 3-23, 5-2, 5-8, 7-1, 7-2, 7-9, 8-2,
8-3, 8-7, 8-10, 8-14, 8-20, 8-21, 8-25, 8-33, 8-37, 8-38,
8-39, 8-40, 8-41, 8-42, 8-46, 8-47, 8-49, 8-53, 8-57
Water Banking, 8-29, 8-33
Water Conservation, 7-15, 7-16, 7-17, 7-18, 8-29, 8-33, 8-
52, 8-53
Water Environmental Laws, 3-25
Water Exchanges, 8-29, 8-33
Water Needs and Demands, 6-3, 6-5
Water Quality, 3-25, 3-26, 3-29, 3-31, 4-3, 4-4, 4-8, 4-9, 4-
10, 5-15, 5-21, 5-23, 6-27, 7-10, 7-13, 7-14, 7-18, 8-3,
8-26, 8-47, 8-49, 8-52, 8-59, 8-60, 9-1, 9-3
Water Quantity, 4-1
Water Right Transfer, 8-29, 8-34
Water Rights, 1-3, 3-12, 3-13, 3-14, 3-15, 3-18, 3-19, 3-20,
3-21, 3-22, 4-2, 5-3, 5-12, 5-15, 5-19, 5-20, 5-21, 6-5, 6-
21, 6-29, 6-30, 7-5, 7-6, 7-7, 7-9, 7-16, 8-27, 8-29, 8-31,
8-32, 8-33, 8-34, 8-47, 8-50
Water Use, 1-1, 1-2, 3-8, 3-9, 3-11, 3-12, 3-14, 3-16, 3-21,
3-22, 3-24, 4-3, 5-1, 5-2, 5-3, 5-5, 5-10, 5-11, 5-12, 5-
13, 5-17, 5-18, 5-20, 5-21, 6-1, 6-4, 6-7, 6-13, 6-15, 6-
16, 6-18, 6-20, 6-21, 6-26, 6-28, 6-30, 7-13, 7-15, 7-16,
7-17, 7-18, 8-1, 8-3, 8-19, 8-29, 8-31, 8-33, 8-36, 8-43,
8-45, 8-51, 8-52
Water Use Opportunities, 8-1, 8-19, 8-29, 8-33, 8-36, 8-45,
8-51
Waterfowl Hunting, 5-15, 5-16, 5-17, 6-23, 6-24, 6-26
Weather Modification, 8-29, 8-34
Well, 4-3, 4-5, 4-6, 4-7, 4-10, 5-5, 5-6, 5-8, 5-18, 5-20, 6-2,
6-3, 6-21, 6-22, 6-27, 6-29, 6-30, 7-2, 7-7, 7-10, 7-14, 7-
17, 8-8, 8-30, 8-33, 8-44, 8-48, 8-49, 8-52, 8-58, 8-59,
9-1
Wetlands, 3-26, 5-22, 6-27, 6-28, 7-17, 8-5, 8-13
Wetlands and Wildlife Habitat, 6-27
Wildlife, 3-2, 3-12, 3-25, 3-26, 3-29, 5-19, 5-21, 5-22, 5-
23, 6-26, 6-27, 6-28, 8-3, 9-2, 9-4
Wind Generation Plant, 6-20
Wind River Indian Reservation, 3-21, 3-22, 5-2, 5-18, 6-30
Wind/Bighorn Rivers, 1-3, 3-12, 3-21, 3-24, 4-2, 5-3, 5-5,
5-6, 5-7, 5-9, 5-11, 5-12, 5-15, 5-16, 5-18, 5-19, 6-2, 6-
3, 6-5, 6-6, 6-12, 6-13, 6-15, 6-16, 6-18, 6-20, 6-21, 6-
24, 6-27, 6-28, 6-29, 6-30, 7-5, 7-7, 7-8, 7-9, 7-14, 8-50,
8-51, 8-52, 8-53, 8-55, 8-57, 8-58, 8-60
Wyoming Department of Environmental Quality, 3-25, 3-
30, 3-31, 4-4, 9-1, 9-3
Wyoming Water Development Commission, 1-1, 3-12, 6-
30, 7-18, 8-2, 9-1, 9-2
Wyoming Water Law, 3-12, 8-27
Yellowstone River Compact, 3-16, 8-34, 8-35, 8-50

Wyoming Water Development
Commission
October 2007
WYOMING FRAMEWORK
WATER PLAN
VOLUME II
PLANNING
RECOMMENDATIONS

This report was prepared by:
Consulting Team
WWC Engineering
Hinckley Consulting
Collins Planning Associates
Greenwood Mapping, Inc.
States West Water Resources Corporation
State Agencies
Water Development Office
State Engineer’s Office
Game & Fish Department

Wyoming Framework Water Plan
Volume II Planning
Recommendations
October 2007
This report was prepared for:
Wyoming Water Development Commission
6920 Yellowtail Road
Cheyenne, WY 82002
This report was prepared by:
Consulting Team
WWC Engineering
Hinckley Consulting
Collins Planning Associates
Greenwood Mapping, Inc.
States West Water Resources Corporation
State Agencies
Water Development Office
State Engineer’s Office
Game & Fish Department

I, Murray T. Schroeder, a Wyoming registered Professional Engineer, certify that this
Wyoming Framework Water Plan, Volume II report was prepared by me or under my
direct supervision. (The original signature and stamp are available at the Water
Development Office.)
I, Bern Hinckley, a Wyoming registered Professional Geologist, certify that this
Wyoming Framework Water Plan, Volume II report was prepared by me or under my
direct supervision. (The original signature and stamp are available at the Water
Development Office.)

TABLE OF CONTENTS
1.0 INTRODUCTION ......................................................................................................................1-1
2.0 INFORMATION AND DATA...................................................................................................2-1
2.1 BASIN ISSUES........................................................................................................................2-1
2.2 WESTERN STATES SURVEY...............................................................................................2-1
2.3 SURVEY OF AGENCY PERSONNEL AND WATER MANAGERS ..................................2-4
2.3.1 Audience ..........................................................................................................................2-5
2.3.2 Overall Purpose of the Framework Plan..........................................................................2-5
2.3.3 Groundwater Data............................................................................................................2-5
2.3.4 Other Critical Issues.........................................................................................................2-5
2.3.5 Public Involvement ..........................................................................................................2-6
2.3.6 New Uses for Unused Water............................................................................................2-6
2.3.7 Presentation......................................................................................................................2-6
2.4 E-MAIL SURVEY ...................................................................................................................2-6
2.5 AGENCY LEADER MEETING..............................................................................................2-7
3.0 RECOMMENDATIONS FOR FUTURE PLAN STRUCTURE AND CONTENT .............3-1
3.1 STRUCTURE AND GENERAL SCOPE ................................................................................3-1
3.2 PLANNING METHODS .........................................................................................................3-3
3.3 BASIN PLAN ORDER ............................................................................................................3-4
4.0 AGENCY PLANNING RECOMMENDATIONS ...................................................................4-1
4.1 WATER DEVELOPMENT OFFICE DIRECTOR STATEMENTS.......................................4-1
Framework Water Plan.................................................................................................................4-1
Storage Projects............................................................................................................................4-1
New Development Program..........................................................................................................4-2
Rehabilitation Program ................................................................................................................4-2
Transbasin Diversion Projects .....................................................................................................4-2
Drought.........................................................................................................................................4-2
4.2 STATE ENGINEER’S OFFICE ..............................................................................................4-3
Surface Water ...............................................................................................................................4-4
Transbasin Diversions ..................................................................................................................4-5
Groundwater.................................................................................................................................4-5
Board of Control/Field Administration.........................................................................................4-6
Interstate Streams .........................................................................................................................4-6
Conclusion ....................................................................................................................................4-7
4.3 WYOMING GAME AND FISH DEPARTMENT ..................................................................4-7
4.4 BASIN ADVISORY GROUPS................................................................................................4-8
Bear River Basin...........................................................................................................................4-8
Green River Basin.........................................................................................................................4-8
Northeast River Basin ...................................................................................................................4-8
Platte River Basin .........................................................................................................................4-9
Powder/Tongue River Basin .........................................................................................................4-9
Snake/Salt River Basin..................................................................................................................4-9
Wind/Bighorn River Basin ..........................................................................................................4-10
Statewide Recommendations Developed through the Planning Process....................................4-10
5.0 SUMMARY OF ISSUES AND RECOMMENDATIONS FOR FUTURE RIVER BASIN
PLANNING ..............................................................................................................................................5-1
5.1 BASIN BASED RECOMMENDATIONS…………………………………………………..5-2

LIST OF TABLES
Table 1
Summary of Ideas, Issues, and Recommendations from the Facilitated Agency Leader
Meeting.............................................................................................................................2-8
LIST OF FIGURES
Figure 1
Conceptual Planning Process……………………………………………………………2-2
APPENDICES
A. EXECUTIVE SUMMARIES AND BAG ISSUES LISTS
Bear River Basin
Green River Basin
Northeast River Basin
Platte River Basin
Powder/Tongue River Basin
Snake/Salt River Basin
Wind/Bighorn River Basin
B. WESTERN STATES SURVEY
C. FUTURE BASIN PLAN ORDER
D. PUBLIC COMMENTS

1.0 INTRODUCTION
1.0 INTRODUCTION
The Wyoming Framework Water Plan has two
objectives. The first objective is to provide basic data and
information regarding Wyoming’s water resources. Volume
I of the Framework Water Plan addresses that objective by
presenting a statewide perspective on the distribution of
water, water quality, present water uses, and projected water
uses. The second objective, and the subject of Volume II of
the Framework Water Plan, is to provide future water
resource planning direction to the State of Wyoming.
Preparation of the Framework Water Plan Volume I
relied heavily on the assembly of data and information
prepared during seven basin planning efforts between 2000 and 2006. Volume II offers planning and
management direction that is the result of synthesizing a body of ideas from the following sources:
! Ideas, opinions, and issues collected from water users through the Basin Advisory Group
(BAG) meeting process.
! Results of a three-tiered planning survey, which included an e-mail survey, conversations
with water managers, and a facilitated agency leaders meeting.
! Results of a survey on the planning processes of several other western states.
! Observations on the existing planning process noted by the consulting team during the
assembly of Volume I.
! Ideas and opinions of state agency staff that were tasked with providing input and direction to
this project (Wyoming Water Development Commission [WWDC], State Engineer’s Office
[SEO], and Water Resources Data System [WRDS]).
Chapter 2 of this Volume II report summarizes the information, data, planning ideas, and
suggestions obtained from the BAG process and the three-tiered planning survey performed by the
consulting team. Chapter 3 presents recommendations for the structure and content of future basin and
framework plans. These recommendations are the result of the consulting team’s observations during the
assembly of Volume I. Chapter 4 offers recommendations focused more on the general planning and
management direction that various state agencies have provided. Chapter 5 provides a summary of issues
and recommendations for future river basin planning.
1-1

2.0 INFORMATION AND DATA
2.0 INFORMATION AND DATA
2.1 BASIN ISSUES
During the summer of 2006, BAG meetings were held in each of the seven basins to present
progress on the Framework Water Plan project. In addition, the meeting forum was used to interact with
the BAG about the Issues List each BAG had compiled during preparation of the individual basin plans.
These lists were updated at the 2006 summer BAG meetings. Copies of these lists are presented in
Appendix A, along with the executive summaries of the basin planning reports for each basin.
During these meetings, the Framework team interacted with the BAGs in an attempt to better
understand the basin-specific issues and to promote discussion about how the planning process could be
advanced from an issues discussion to the development of goals and solutions.
Figure 1 is a schematic depicting how water planning and project construction are currently
assisted by the WWDC. The primary responsibility for basin planning is the State’s, and the focus of
basin planning is on data. Also shown in Figure 1 is the concept that problem definition, alternative
evaluation, and follow-through are the responsibility of individual project or program sponsors, the
ultimate water users.
2.2 WESTERN STATES SURVEY
As part of the Framework planning project, the consulting team
performed a survey of several western states’ water planning programs.
The goal of the survey was to understand the planning approaches and
ideas used in other states. The survey was directed at a wide spectrum
of water planning programs, from simple to complex and minimally
funded to highly funded. The survey included phone conversations with
planning staff and website reviews for Colorado, Idaho, Montana,
Kansas, Texas, Nebraska, and Utah. With the exception of Kansas and
Texas, all these states share borders and have common drainages with
Wyoming. The Western States Survey is included in its entirety in
Appendix B.
2-1

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2.0 INFORMATION AND DATA
As expected, states all have their unique philosophies and approaches to water planning. Also,
some states appear to be more active and effective than others. Based on the examination of planning
ideas and methods from the seven other western states, the consulting team formulated several water
planning principles for the Wyoming Water Planning program. Many of these principles are already
being followed, and therefore, this listing is not a critique of Wyoming’s existing process.
1. Complete Projects. Continue following through on development projects and planning goals.
Maintain a clear process that allows projects and planning initiatives to be proposed,
evaluated, and completed.
2. Set Goals and Objectives. The planning process should establish goals and objectives to
guide water-related decisions. Goals should be lofty and yet achievable. For example, one
statewide planning goal might be to ensure that the water legally allocated to Wyoming under
interstate compacts and court decrees is not usurped by downstream states that develop uses
for this water before Wyoming does. An objective would be to perform incremental steps to
achieve these goals. Objectives might be to first quantify these allocations (this requires data
on quantity, quality, and use of water resources), then prepare specific plans to develop the
water and obtain the necessary permits and designs, even if the actual projects are not
constructed until some unknown future date. This would put downstream states on notice
that this water is not available for their use just because Wyoming’s needs are not immediate.
3. Pursue a Broad Approach. Pursue a broad approach to water resource planning that includes
evaluating the appropriateness of conservation and resource management techniques in
addition to project development.
4. Create Local Results. Focus on solving problems and addressing issues that are important to
the local residents, which may include referring an issue to another state agency. Place value
on citizens seeing local results of water resource planning.
5. Maintain a Long-term Perspective. Involving local committees in solving their immediate
problems through construction of water supply projects can provide tangible short-term
results. However, a comprehensive long-term vision is needed to assure that Wyoming’s
water resources are being developed and used wisely in the best interests of the residents of
the state.
6. Remain Flexible. Water planning must be flexible in order to accommodate changing
priorities to meet new and unanticipated needs and opportunities while keeping the long-term
goals in view.
7. Pursue Meaningful Planning. Avoid preparing basin plans for the sake of planning. Update
these plans as needed but do not become a slave to a standard cycle of updates when they
may not be needed. Instead, include the study and planning of issues that transcend basin
boundaries to ensure all important topics are covered.
2-3

2.0 INFORMATION AND DATA
8. Evolve the Planning Process Rather Than Simply Repeating It. Move past the first stage of
planning in which data are collected and issues are identified. A deeper level of
understanding issues comes from preparing to implement plans. Develop strategic plans to
follow through on the results of planning, which may require more detailed information.
9. Coordinate the Players. Coordination and communication among program personnel are
critical and some type of structure is needed for this to occur. Convene on a regular basis the
decision-makers of all agencies that are involved in water resources.
10. Involve the Local Citizens in Meaningful Ways. Establish balanced and representative local
groups to provide input into water resource planning. Helping these local groups craft and
recommend solutions to local issues sustains local participation. When the solutions and
implementation strategies come from the local level, a message is sent to the legislature that
the water planning program is solving problems and addressing issues.
11. Establish a Report Card. A method of measuring progress on achieving long-term goals
should be prepared as part of the water planning program. It should focus on two things: the
amount of positive influence that was brought to bear on issues and problems, and the level of
knowledge and understanding of water issues among the legislature and general public.
Detailed documentation for the Western States Survey is included as Appendix B. Wyoming
water planning may benefit from periodic reviews of the planning efforts of other states, particularly those
that share use of waters through interstate compacts and court decrees.
2.3 SURVEY OF AGENCY PERSONNEL AND WATER MANAGERS
As part of the Framework planning project,
the consulting team conducted interviews with water
managers and state and federal personnel. The
interviews were performed on the phone and based
in part on a standard list of questions. The objective
of the survey was to obtain input on how the
Framework and basin planning processes can be
made most useful to agencies and stakeholders.
Detailed results of the survey are included in a
separate project technical memorandum. A summary of the “Response Highlights” from the survey work
is provided below along with the consulting team’s recommendations.
2-4

2.0 INFORMATION AND DATA
2.3.1 Audience
The survey documented that there is a wide range of expectations when it comes to the intended
audience for the Framework Plan, from “everyone” to “legislative”. Audience identification is an action
that can help focus the purpose and content of documents such as those prepared during the Framework
and basin planning processes.
Recommendation: The State should consider defining who the singular audience is or prioritizing
multiple audiences when initiating future basin planning and Framework planning documents. If
consultants are hired to assist with planning, then the audience definition might be included in the
contract scope of work. The utility and focus of the planning documents and other products may be
enhanced if they are directed at a clearly defined audience or priority if multiple audiences are considered.
2.3.2 Overall Purpose of the Framework Plan
Interviewees suggested that the Framework Plan serve a dual purpose in providing data unique to
the water planning program and references or links to other data sources and information of other
agencies and groups.
Recommendation: The State should embrace the concept of authoritative data sources and avoid
assembling static data that are already maintained and made available by other agencies. An example of a
WWDC authoritative data set would be the estimates of current and future water supply needs by water
use sector. An example of data that WWDC should rely on others to maintain includes gaging station data
for surface water resources.
2.3.3 Groundwater Data
The most frequently identified shortcoming of existing information and plans pertained to
information on groundwater.
Recommendation: The State should place a greater emphasis on developing or assembling (or facilitating
the work by others) useful groundwater information, and perhaps the next round of basin plans should
approach the groundwater data issue on a statewide basis.
2.3.4 Other Critical Issues
The survey collected opinions on several issues that appeared controversial or critical. These
issues included ones such as the conflicts between instream and out-of-stream uses, coal bed methane
(CBM) gas development and the associated water discharges, and challenges between agricultural uses
and municipal uses.
Recommendation: As policy-makers resolve these critical issues, further water planning should
incorporate the results of current policy direction.
2-5

2.0 INFORMATION AND DATA
2.3.5 Public Involvement
The survey collected a wide range of responses related to the public involvement process (BAG
program), administered by the WWDC.
Recommendation: The State should perform a critical review of the BAG process, including the goals,
formation, and maintenance of these groups. The review should strive to define a process that adopts new
ideas that show promise for maintaining BAG viability and effectiveness.
2.3.6 New Uses for Unused Water
The consensus among the interview sample
was that planning should focus on identifying where
and in what quantity water is available for new uses,
and that specific opportunities for using water would
likely change over time as dictated by economic
forces.
Recommendation: In basin water planning and
Framework plans of the future, the State should
consider investing more work in the development of
water availability estimates, (like how much groundwater is available) before investing in a refinement of
the process for identifying and ranking water use opportunities (Chapter 8). Evaluating opportunities at
the reconnaissance level in basin planning is legitimate; however, refined investigations of opportunities
are best performed when the demand for refined evaluation comes from an actual project sponsor.
2.3.7 Presentation
Survey results confirmed that there is a significant demand for the availability of real-time data
and planning information, and that the need for paper planning documents continues to decline in relative
importance.
Recommendation: The State should fund the efforts needed to maintain a water planning program that
delivers data and information in technologically advanced ways. The State should continue to explore
ways in which relevant data sources from other agencies can be made available through the water
planning program website.
2.4 E-MAIL SURVEY
An e-mail survey was performed in October, 2006, in which questions were asked regarding the
future direction of the Framework Water Plan. The distribution list included 1,020 e-mail accounts,
primarily those identified through BAG participation. Fifteen replies were received. The content of the
replies covered a wide range of subjects, including many that had been identified in other forums.
However, there were very few common subjects mentioned in the responses, making it difficult to
identify a widespread or general response useful for planning purposes. The complete survey responses
are included in the working papers of this project.
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2.0 INFORMATION AND DATA
The poor response to the e-mail questionnaire (1.5 percent response rate) indicates that e-mail
should not be used as a mode of generating interest in or input on water planning. In fact, a
recommendation of this current study is to abandon the use of e-mail for obtaining information and use it
only as a means of providing meeting or other notification to future BAG membership.
2.5 AGENCY LEADER MEETING
On October 18, 2006, a facilitated agency leader
meeting was held in Cheyenne led by a panel representing
the WWDC, SEO, Wyoming Department of Environmental
Quality (WDEQ), Wyoming Game and Fish Department
(WGFD), and Wyoming Business Council. The purpose of
the meeting was to gather ideas from the panel and the
public audience regarding what the Framework Planning
Recommendations report should attempt to address. Table 1
presents a summary of the ideas and subjects recorded at this
meeting.
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2.0 INFORMATION AND DATA
Table 1
SUMMARY OF IDEAS, ISSUES, AND RECOMMENDATIONS
FROM THE
FACILITATED AGENCY LEADER MEETING
OCTOBER 18, 2006
IDEAS AND ISSUES THE
FRAMEWORK WATER
PLAN SHOULD INCLUDE
The Plan should express a
statewide view. Where are the
water resources, and where is
water needed?
The Plan should look at ways to
address shortages (conservation,
storage, transbasin diversions)
The Plan should express
Wyoming’s intent to develop its
water resources.
The Plan should define the
questions that must be answered
for Wyoming to protect,
conserve, and develop its water
resources.
There should be a web-based
GIS and database tool developed
for future planning and data
dissemination as part of the
Framework Plan.
RECOMMENDATIONS ON THE
GENERAL PLANNING
DIRECTION THE STATE MIGHT
OFFER
The State should gather data statewide
on water availability and use.
Through the planning process, the
State should identify where stream
gages are necessary.
The State should evaluate and assess
its groundwater resources.
The State should continue to better
define the interconnection between
surface water and groundwater
The State should continue developing
and rehabilitating water infrastructure
within the state, (municipal and
agricultural).
The State, through the planning
process, should identify areas where
water infrastructure rehabilitation is
needed.
The State should identify areas where
conservation helps Wyoming make
more effective use of its water.
The State should continue and improve
its statewide planning process.
RECOMMENDATIONS ON THE
STRUCTURE AND CONTENT OF
FUTURE PLANS
Other agencies such as the Game and
Fish Department, and the Department
of Environmental Quality, Water
Quality Division (DEQ/WQD) should
be included in water planning. Other
agencies should be involved in
reviewing the river basin plans to
allow a broader view.
Future planning efforts should try to
look at all potential data sources.
Future planning efforts should address
climate variability and extended
drought. Future river basin plans
should identify sustainable water
supplies.
There should be a strong outreach and
education program developed for river
basin planning.
An outreach program should be
targeted to improve and continue BAG
participation.
Future river basin plans should help
local policy-makers and BAGs set
goals for water development.
The river basin planning process
should consider other local planning
processes such as wellhead protection
plans, source water protection plans,
and watershed plans.
Future river basin plans should be
web-based and present data and maps
for easy use.
The digital river basin plans should
incorporate or link to other agencies’
databases.
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3.0 RECOMMENDATIONS FOR FUTURE PLAN STRUCTURE AND CONTENT
3.0 RECOMMENDATIONS FOR FUTURE PLAN
STRUCTURE AND CONTENT
During the preparation of the Framework Water Plan, the consulting team and state staff noted
improvements that could be made in preparing future updates to the basin planning and Framework
products. This chapter outlines those recommendations.
3.1 STRUCTURE AND GENERAL SCOPE
The next round of basin plans and next Framework Plan should have the same organization as the
2007 Framework Plan, and address the following general scope:
1.0 Introduction - Introduce the purpose and scope of the plan.
2.0 Presentation Tool - Outline the use of the web-based presentation tool. The presentation
tool should be a Framework product only and not a product of individual basin plans. The
basin efforts will simply be providing updated data for the tool database. Therefore, the
narrative that is written in the 2007 Framework Plan should be able to be updated and used
as Chapter 2 of the seven basin plan updates.
3.0 Setting - Summarize the following:
! Current economic and social conditions, including population, employment
statistics, and other similar data.
! The institutional constraints on water use (water rights, compacts, permitting,
etc.).
! Basic physical information about the basin, including topography, temperature,
rainfall, etc.
4.0 Resources – Include the following:
! Provide estimate(s) of the hydrologically sustainable water supply in terms of
surface water and groundwater, with a graphical presentation of where those
resources are located. The goal is to characterize the resource without regard to
how it is currently being used. However, the estimates must also identify the
obligations the State has to downstream states.
! Evaluate the effects of climate change or climate variation on water resources.
There is evidence that climate variability is more pronounced than what can be
deduced from a study of climate records. Evaluate the need to modify hydrologic
procedures for estimating water supply availability. If needed, define new
methods that provide estimates of supplies with a high degree of reliability.
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3.0 RECOMMENDATIONS FOR FUTURE PLAN STRUCTURE AND CONTENT
5.0 Current Use - Provide estimates of:
! How the water resource presented in Chapter 4 is being depleted.
o Agriculture.
o Municipal and Domestic.
o Industry.
o Miscellaneous (wildlife, phreatophytes, etc.).
! Evaporation abstractions from the entire water resource. These should be
assigned to each water use sector associated with the depletion. As an example,
evaporation from a municipal water supply reservoir should be assigned to that
municipality. In addition, evaporation from reservoirs constructed in Wyoming
to provide water supplies for downstream states should be assigned to
downstream states’ allocations under the respective interstate compact(s) or court
decree(s).
! How much is being depleted in acre-feet per month, and total annual depletion
during wet, normal, and dry years.
! How much is being diverted in acre-feet per month, and total annual diversions
during wet, normal, and dry years.
! The timing of the water depletions and diversions by month during wet, normal,
and dry years.
! How water resources are being used in other ways that do not deplete the supply,
but limit or restrict use by other sectors, including:
o Recreation.
o Instream flows.
o Wetlands.
6.0 Future Needs - What are the projected water needs of the water-depleting sectors and the
non-depleting sectors? These needs should be defined in terms of amount (volume and/or
rate as appropriate), timing, location, and quality.
7.0 Availability - Where, when, and in what amounts is there water supply that is in excess of
that required to meet present uses and legal obligations including existing water rights and
interstate compacts?
8.0 Opportunities - Where and in what configuration are the opportunities for meeting
projected needs that meet screening criteria? Apply the “best criteria” from the previous
seven plans.
9.0 Strategies – Include strategies for how to achieve the goals arrived at during the planning
process.
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3.0 RECOMMENDATIONS FOR FUTURE PLAN STRUCTURE AND CONTENT
3.2 PLANNING METHODS
As part of this Framework project, the consulting team prepared several technical memoranda
that presented suggested methods and improvements for the State’s water resources planning program.
Following is a brief sample of widely ranging ideas.
! Generally, the next round of basin updates should be done using consistent and technically
sound approaches in all basins to provide comparable and complete information statewide.
! The tables and figures in Volume I of
this Framework Plan form an outline
for the data that should be collected,
compiled, and presented in the next
round of basin planning. Future basin
plan updates and Framework updates
should provide information so that
these tables and figures can be
completely and easily constructed.
This work should be closely
coordinated with the web-based
presentation tool data requirements,
which are outlined in a project technical memoranda.
! Prior to the next round of basin plan updates, the State should use a better economic
forecasting methodology that takes into account how tourism would impact water needs for
the future, both directly and indirectly.
! The State should consider abandoning simple water supply models as they were prepared in
the last round of basin plans in favor of other models (WIRSOS or STATEMOD) that
explicitly account for water rights.
! Future basin and statewide water planning might investigate how water use and water needs
are changing on a regional scale. The State of Wyoming should have a clear sense of how
water use sectors are changing in states that share water with Wyoming.
! Performing basin plan updates to capture recent changes in conditions that are short-term in
nature is not wise or realistic. Social, political, and economic conditions are constantly
influencing water use, needs, and opportunities. Updates should be considered if a reasonable
argument can be made that the high or low population forecasts do not capture actual
conditions.
! The Framework Plan and basin plans were originally conceived as a dynamic process that
would be updated periodically. Updating every aspect of a basin plan (with its present
content) at frequent intervals is not needed or cost-effective. Typically, only a few items will
change. As an example, agricultural water use has changed little since the 1973 Framework
Plan; however, population/municipal need has changed dramatically.
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3.0 RECOMMENDATIONS FOR FUTURE PLAN STRUCTURE AND CONTENT
A number of more specific recommendations for improving the planning process and products
are reported in the form of project technical memoranda. State agency water planning staff, and other
interested parties, should consult the following memoranda for more planning suggestions:
o Skeleton Review Material for Framework Water Plan, WWC Engineering, April
28, 2006.
o GIS Technical Memorandum, Greenwood Mapping, Inc., April 16, 2007.
o Vol. II – Future Wyoming Water Planning Technical Memorandum, Hinckley
Consulting, April 18, 2007.
o Presentation Tool Technical Memorandum, Greenwood Mapping, Inc.,
November 22, 2006.
o Recommendations and Ideas for Content and Structure of Future Basin Plans,
WWC Engineering, April 20, 2007.
3.3 BASIN PLAN ORDER
As part of the Framework planning process, the consulting team evaluated the order in which
future basin plans should be performed. Appendix C contains information related to this work. The
evaluation used a matrix approach that considered five factors, including:
! Completion date of last basin plan. The older the plan, the more deserving it was of an
update.
! Forecasted population increase. Basins with large projected population increases received
more consideration.
! Relative number of identified BAG issues. Basins with large issues lists received more
weight.
! Components of plan that need to be updated or improved. This factor is needed to address
deficiencies in the current plans.
! Relative number of compact issues. More weight was given to basins that appeared to have
more critical downstream state compact issues.
In addition to the forecasted population increase, the evaluation compared the 2000 census
population and estimated 2005 population for each basin to the projected range of populations reported in
each plan. This comparison was done graphically, and the results are included in Appendix C. As the
graphs in Appendix C show, all of the basin planning efforts have actual population estimates that match
up reasonably well with projected populations, with perhaps the exception of the Green River Basin.
The matrix evaluation combined with an interpretation of the population plots provides a basis for
recommending the following basin plan ordering for the next planning round:
! Green
! Powder/Tongue
! Northeast
! Wind/Bighorn
! Salt/Snake
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3.0 RECOMMENDATIONS FOR FUTURE PLAN STRUCTURE AND CONTENT
! Bear
! Platte
One factor was not considered in the evaluation of future basin plan order: political interest.
Irrespective of actual planning need, some basins have more active and determined water planning and
water issues stakeholders. While this factor is difficult to assign value to, it is very real and should not be
ignored in determining which basins receive planning support prior to others, if at all. The success of
planning and the projects that arise from planning is largely driven by this consideration.
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4.0 AGENCY PLANNING RECOMMENDATIONS
4.0 AGENCY PLANNING RECOMMENDATIONS
This chapter presents several specific planning goals, activities, and recommendations that
several state agencies have committed to performing.
4.1 WATER DEVELOPMENT OFFICE
Framework Water Plan
The Framework Water Plan serves to revisit the work performed over the past eight years on the
seven river basin plans for the following major purposes:
1. Provide a statewide perspective of the status of Wyoming’s water resources.
2. Define improvements to our planning efforts that can be used as the seven basin plans are
updated.
3. Identify water development opportunities to promote interest from potential project
sponsors.
Storage Projects
The Wyoming Water Development Program (the
Program) must remain committed to the construction of
reservoirs. Increased federal requirements have made the
construction of large dams on mainstem rivers very costly
and, absent federal reform to these requirements, virtually
infeasible. Therefore, the Program should concentrate on
smaller reservoirs on tributaries or off-channel reservoirs
where any environmental consequences can be effectively
mitigated and managed. In addition, enlargements of
existing reservoirs should be considered.
Reservoir projects are more feasible if the Program
works with project sponsors who are willing to commit political and financial capital towards the
construction, operation, and maintenance of the project. In these situations, the Program should fund the
permitting and design costs and provide construction funding commensurate with any water supply
benefits it may retain for environmental purposes or future marketing. The sponsor should be able to
retire a portion of the construction costs through a loan from the Program. The amount of the loan would
be based on ability to pay for the benefits that the sponsor will realize. The sponsor should be responsible
for operation and maintenance of the dam and appurtenances. The Wyoming Water Development
Commission (WWDC) and the Legislature’s Select Water Committee may need to revisit existing criteria
and statutes relating to the appropriate grant/loan mix for sponsors of storage projects. One of the goals
of this Framework Plan is to attract project sponsors who may be willing to develop a partnership with the
Program to pursue a storage project.
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4.0 AGENCY PLANNING RECOMMENDATIONS
In addition, developing partnerships with industries to construct new storage should be pursued.
The Program’s role in such partnerships would be to assist in the permitting of the project and invest in a
portion of the storage for purposes of supplemental municipal and irrigation supplies.
Much of the permitted capacity in existing reservoirs is eroding due to the accumulation of
sediment. Given the value of storage to the state and the fact that many dams fill only in wet years,
perhaps the State’s one-fill rule should be revisited to allow dam owners to ensure that the total permitted
capacity is either used or stored.
New Development Program
Wyoming statutes provide guidance regarding the priorities for projects to be funded under the
New Development Program. The statutes advise that the New Development Program should emphasize
the development of unappropriated flow. The recent increases in demand on the Program and increased
construction costs have caused the WWDC to begin discussions regarding the prioritization of projects
when funds are limited. When funds are limited, projects that address public health and safety issues
should be a priority.
Historically, the Program has promoted the regional approach to solving municipal and domestic
water supply problems. This approach serves to reduce costs and promote efficiency and should continue
in the future.
Rehabilitation Program
Funding for the Rehabilitation Program is also being stressed by increased demands and
construction costs. Interest in the Program is evidence that the state’s water infrastructure is aging. When
funds are limited, projects that address health and safety issues, as well as projects in immediate need of
repair and replacement, should be priorities.
Transbasin Diversion Projects
Anytime water planners discuss the long-range future, the issue of transbasin diversions arises.
Such discussions tend to predispose what the future may bring in terms of the highest and best use of the
water for the benefit of the State of Wyoming. We simply do not presently have the foresight to suggest
that the water may be better utilized in one particular water basin than another. Some basic tenets need to
be established to guide such discussions. First, there should be assurance that the water basin that would
receive the water has effectively developed and is using the supplies available in-basin before transbasin
diversions should be considered. In the event a transbasin diversion project is pursued, any resulting
impacts to the basin providing the water must be mitigated.
Drought
The prior appropriation doctrine mandated by Wyoming water law serves as a very good tool to
manage drought as it determines who gets water when the supply is limited. It is not practical to expect
the Program or any other state or federal program to hold Wyoming water users harmless from priority
water rights administration in a drought like we are presently experiencing. Water users must continue to
look at their own operations in order to mitigate the impacts of drought. Some examples:
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4.0 AGENCY PLANNING RECOMMENDATIONS
1. Irrigators may want to ensure that their most senior water rights are on their most productive
lands. This would assist in achieving the maximum benefits from a limited water supply.
Moving the senior water rights will require approval of the Wyoming Board of Control, and
there are some costs associated with the preparation of the necessary petitions. However,
these costs may be good investments and should be considered on a case-by-case basis.
2. It is incumbent on municipalities and purveyors of domestic water to ensure that their citizens
have enough water for the public’s health and safety. Many Wyoming communities have
programs that place restrictions on the watering of lawns and gardens during periods of
limited supplies. These restrictions serve to reduce the demand on available storage water or
groundwater supplies. However, municipalities relying solely on direct flow diversions gain
little from such water restrictions. These communities need to pursue supplemental supplies
or obtain water from senior water rights through temporary use agreements in times of
drought when their direct flow water rights may be subject to regulation.
3. Most industrial water users have developed water supply portfolios that are capable of
providing water during drought conditions. Due to their considerable investment and
responsibility to ensure delivery of their products, industries make very conservative
estimates regarding drought in establishing their water supplies. However, during extreme,
short-term events, the industries will likely turn to temporary use agreements with water users
with very senior water rights to meet their needs.
4.2 STATE ENGINEER’S OFFICE
Water management in the West and in Wyoming has seen, and likely will continue to see,
change. The water planning process is an important tool in identifying what potential changes the state
faces and how we can position ourselves to best meet those challenges. As Wyoming has developed its
water resources more slowly than some of our neighboring states, we have the opportunity to see how
those states have responded to increasing demand on their water supplies, and hopefully learn from their
experiences. In other areas, such as energy development, Wyoming has creatively responded to the
increasing demands of water permitting and administration where other models to follow did not exist.
The extent of impacts from climate change on water management are difficult to gauge at this time, but if
the current trend of reduced snowpacks, earlier snowmelt, and lower runoff amounts continues, this
agency must be ready to address the impacts of those changes. In many ways, the prior appropriation
system is well positioned to handle these changes.
The water planning process documents Wyoming’s intent to put to use the allocations that have
been made to the state through interstate compacts and decrees. Wyoming relies on this water to meet
Wyoming’s future needs, irrespective of downstream states’ earlier development and continuing increases
in water demands. While those states continue to put water to use, the river basin compacts and decrees
provide certainty that water will be available for Wyoming citizens to meet our future water development
needs.
The following comments regarding the importance of water planning on future water use in
Wyoming are structured to correspond with the water management roles of each division of the State
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4.0 AGENCY PLANNING RECOMMENDATIONS
Engineer’s Office (SEO):
interstate streams.
surface water, groundwater, Board of Control/field administration, and
Surface Water
Wyoming’s earliest pioneers recognized the importance of a dependable water supply as they
settled the state. The vast majority of early priority water rights in Wyoming are direct flow surface water
rights for irrigation. The property right that is conferred with an adjudicated water right makes these early
water rights a very valuable commodity. As the state’s economy diversifies over the planning horizon of
this study, it is likely the municipalities and industries that require a consistent, dependable water supply
will look to these senior agricultural water rights for transfer. While permanent transfers are possible
under existing water law, and qualifying temporary changes of use are allowed for up to two years, more
flexibility in the ability to transfer water rights on a temporary basis may be sought by water users.
Concepts such as rotational land fallowing and dry year leasing have been used in other states to keep
agricultural water rights tied to the land but give the water right holder the flexibility to make contractual
arrangements with others in need of a dependable water supply during times of drought. These
arrangements keep the land in the agricultural land base, which is good for county governments and local
economies. It also provides water to those entities in need of water only in the years when their other
water supplies are insufficient without permanently severing the water rights from the land. It is
conceivable that these types of arrangements will be explored in Wyoming over the next few decades,
especially in water-short areas such as the North Platte River Basin.
Water conservation is often touted as an easy approach to stretch water supplies. Conservation of
water cannot be forced, however, and creating financial or other incentives to encourage reduced water
consumption is typically required. Water conservation activities can also be complementary in addressing
concerns with aging infrastructure. Wyoming irrigation districts which have storage or delivery contracts
with the U.S. Bureau of Reclamation (USBR) are all required to have water conservation plans in place.
Over a hundred years of use has taken its toll; physical wear and time have deteriorated many of
Wyoming’s major water storage and delivery projects, leading to reduced water delivery efficiencies.
Further, as federal dollars continue to dwindle, funding to replace or repair these projects will likely come
from a combination of sources, not just the federal government. Future water plans should address the
physical condition and continued functionality of aging water projects in each of the basins and estimate
the rehabilitation needs and costs. With this information, funding packages can be investigated, whether
the funding is from federal, state, or private sources.
Wyoming enacted its instream flow law in 1986. The law requires that this type of water right
application be filed by the WWDC, and to date, 100 of these types of applications have been filed. The
law does not allow for a private water right holder to retain its water right and change the existing use to
instream flow. The law currently requires that the right be turned over to the State if the use is for
instream flow. The trend of Wyoming agricultural land being purchased by out-of-state owners is likely
to continue. Some of these landowners are interested in the fishery and environmental attributes of
surface water resources on their properties. The ability to have more flexibility in the use of their surface
water rights will likely be desired, and it is possible that changes to the instream flow statute and
temporary change statutes could occur to accommodate these needs. Since 2002, at least 12 bills
addressing the concepts of temporary in-channel uses or other flexibilities in our temporary use law have
been introduced in the Wyoming Legislature, but none have passed. Basin plans have recognized the
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4.0 AGENCY PLANNING RECOMMENDATIONS
value of water for these purposes, and future plans can provide a forum for the public to provide input on
whether increased flexibility is desired by water right holders for these uses of water.
Transbasin Diversions
The movement of water from areas of relative surplus to areas of need is woven through the water
development history of the West, including Wyoming. It is an issue that can pit users in adjacent river
basins against one another in a provincial manner, or it can be a positive solution for the basin in need
while providing additional development in the basin of surplus via mitigation, all in the effort to better the
lot of the state as a whole. Transbasin movement of water is expensive, time-consuming, and fraught
with political and social debates.
However, it should never be taken out of the portfolio of options for water managers, and the
state itself, when it comes to solving water shortage problems. Wyoming will continue to see pressures
regarding transboundary movement of water and needs to respond to those pressures with creativity and
realism. As we move forward in time, with finite water resources and growing demands in parts of our
own state where the water supplies are fully appropriated, it is a water management alternative that will
be pursued more and more. Future water plans need to address the topic of transbasin diversions and the
ability of this type of project to meet water shortages elsewhere in the state.
Groundwater
Coal bed methane (CBM) development in the state has greatly increased the workload of the
Groundwater Division of the SEO. The extraction of CBM in other parts of the state is likely to expand
over the next few years.
During times of drought, groundwater resources are often developed to supplement dwindling
surface supplies. As more groundwater development occurs in the state, more calls for interference
investigations are likely to be received. Determining the impact of development of groundwater
resources on surface water supplies or other groundwater uses can be difficult and time-consuming.
The first river basin plans were generally cursory in their groundwater evaluations. This has been
recognized in the Green River Basin, and plans are under way to inventory the groundwater information
for that basin. As groundwater work is completed, the water planning process should bear in mind the
regulatory impacts such development will have. Accordingly, the basin plan should gather data helpful
to the regulatory functions of the SEO (such as for evaluating interference claims) as well as for
improving specific knowledge of the state’s groundwater resources.
Technology now exists for drilling and developing very deep groundwater wells, but energy costs
to produce these water supplies may be cost prohibitive depending upon the need for and use of the water.
Some western states are investigating the use of the treatment of shallower, brackish groundwater
supplies to determine if treatment costs could be less than the pumping costs of bringing higher quality,
but deeper, water to the surface for use. The applicability of substituting treated water supplies in
Wyoming is not known at this time, but those involved with river basin plan updates should remain
cognizant of this work, and its applicability in Wyoming could be investigated further as part of future
water plans.
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4.0 AGENCY PLANNING RECOMMENDATIONS
Board of Control/Field Administration
The Board of Control (BOC) is charged with adjudicating water rights in the state, as well as the
review and granting of other changes to adjudicated water rights. The BOC consists of the four Water
Division Superintendents and the State Engineer. Whereas some surrounding states utilize a court system
for these activities, Wyoming’s system provides for those with the most water knowledge and background
to make these decisions. In Wyoming, an individual water right is typically reviewed only when some
type of change is being contemplated for that right, or when a field observation necessitates a change. As
a result, many of the permits of record in this office were originally issued years ago, many prior to 1900,
and have not been reviewed or updated since that time. For this reason, there are many paper water rights
that may not have been exercised for many years, if ever. As we look towards ways to become more
efficient in our water rights recording and administration, information from future water plans describing
water use under valid permits and adjudicated water rights will be very useful in protecting those uses,
especially against downstream claims.
One difficulty encountered during the first round of river basin plans was accurately estimating
the amount of water consumptively used by irrigation relative to the amount of water diverted. The
difficulty stems from not having sufficient data for diversions, water use, and return flow calculations,
which in themselves are cumbersome and highly data-intensive. As technology becomes more
sophisticated, the use of remote sensing products to assess water use will become more common, and the
use of remotely gathered data would greatly improve the accuracy of consumptive use estimates at a
significant cost savings.
Similarly, the SEO’s internal database of water rights is being updated and will be much more
accurate in the future. Other western states’ planning programs compare their water rights database
information with actual water use. Wyoming will likely not take this step in the next round of basin plans,
but Wyoming should not discount its eventual use and utility. Our ability to better understand all water
rights and uses in all basins will be the best way for Wyoming to protect our allocated water.
With recent drought conditions increasing the workload of our water regulation field staff,
technology for more accurate streamflow and diversion amounts will be critical in stretching those field
resources. New methods of water measurement are being developed that decrease the time required at
each measurement site. The SEO is also investing in additional real-time gaging capabilities such that
water availability numbers can be pulled from the computer at the start of the day without a long drive to
visit the gage site. As future water plans are developed, the opportunity exists to assess to what extent
crucial water administration information is being obtained in timely and cost-effective ways. The
“external review” associated with this aspect of water planning provides many opportunities to evaluate
the sufficiency of the current gaging station network and make recommendations for improvement.
Interstate Streams
Products and summaries from the basin water plans and Framework document are immensely
valuable to help document Wyoming’s water use and compliance with interstate compacts and decrees.
Likewise, other products developed for compact compliance are of value to the water planning process.
An example is SEO’s efforts to estimate consumptive uses in the Green River Basin. Information
gathered by the SEO for this program will fit well in the next update of the Green River Basin Plan. One
outcome of the settlement with Nebraska resulting in the North Platte River Modified Decree was the
imposition of significant additional reporting requirements on Wyoming’s use of water. It is foreseeable
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4.0 AGENCY PLANNING RECOMMENDATIONS
that more basin agreements in the West will require detailed evidence of water use by their member
states.
Water requirements for environmental restoration and endangered species recovery are placing
additional demands on already thin water supplies. Wyoming currently participates in three basin-scale
recovery programs, the Upper Colorado Endangered Fish Recovery Program, the Platte River Recovery
Implementation Program, and the Missouri River Recovery Implementation Program. An important
objective of each of these programs is to provide Endangered Species Act (ESA) compliance for the
continued operation of existing water storage, diversion, and use projects and facilities. Maintaining the
ability to develop future water supplies and still meet ESA obligations is an important goal of Wyoming’s
participation in these programs. This assurance is also of value to the Water Planning program providing
a better estimate of the amounts of water available for future use with some certainty that ESA
requirements are met.
As water use has increased across the western United States, it has become imperative that
existing water supplies be stretched as much as possible. For example, the states of the Colorado River
Basin are jointly exploring the feasibility of augmenting supplies through such means as weather
modification, water conservation, water reuse, and desalination. In future Wyoming water planning
efforts, water reuse and augmentation should be investigated to determine the types and locations most
appropriate and practical for a particular basin.
Conclusion
Irrigated agricultural land continues to be the largest consumptive use of water in Wyoming. It is
unlikely that this will change dramatically over the next 30 years, but mechanisms to increase the
flexibility of how those water rights may be utilized by the individual water rights holder will likely be
examined and perhaps expanded. Wyoming will continue to develop its water supplies more slowly than
our downstream neighbors, but documenting our water use and estimating future water demands in each
river basin are both critical and fundamental to Wyoming being able to maintain our ability to develop
our remaining water allocations into the future.
4.3 WYOMING GAME AND FISH DEPARTMENT
Following is a summary of the recommendations made by the WGFD regarding future planning.
! Incorporate resource data from agencies into
a spatial database system to facilitate
dynamic water planning and decision
support. Link to agency databases for
access to current information.
! Incorporate aquatic and terrestrial wildlife
resource data and habitat priorities from the
WGFD.
! Include provisions for state agency
participation. Define clear and consistent
roles and procedures for agency
involvement up front.
4-7

4.0 AGENCY PLANNING RECOMMENDATIONS
! Recognize that while water development and use provide benefits for people, there are
environmental tradeoffs relative to the health of natural aquatic ecosystems and their
associated benefits.
o Develop approaches to incorporate aquatic system values into water planning.
o Avoid major adverse impacts, minimize other impacts, and restore functions of
previously impaired systems.
! Recognize changing demographics in the areas of societal values and future needs.
! Recognize the growing importance of nonconsumptive values.
! Facilitate equal participation opportunity for all interests. Avoid exclusionary processes and
environments.
! Recognize and promote appropriate water conservation.
! Consider effects of climate change in water planning.
4.4 BASIN ADVISORY GROUPS
Bear River Basin
! Participation in the Bear River Regional Water Quality Task Force should be continued to
protect Wyoming’s water resources.
! Planning for future growth should be encouraged to properly manage and allocate
Wyoming’s water resources.
! Methods to meet agricultural water needs should be evaluated.
! Strategies to meet the increasing municipal and domestic water demands should be evaluated.
! Groundwater resources of the Bear River Basin should be described and evaluated.
Green River Basin
! Water storage opportunities should be identified and pursued to improve the reliability of the
irrigation water supply on the tributaries of the Upper Green River Basin.
! Accurate data on water supply and use in the Green River Basin should be obtained.
! Salt loading to the Green River and its tributaries should continue to be reduced.
! Planning for future growth should be encouraged to properly manage and allocate
Wyoming’s water resources.
! Plans for future industrial and municipal water needs within the basin should be developed.
! Groundwater resources of the Green River Basin should be described and evaluated.
Northeast River Basin
! Proper land management and use should be promoted to protect and preserve water quality.
! Careful control and management of coal bed methane (CBM) discharge water should be
encouraged to reduce the impacts to land and water.
! Groundwater resources of the Northeast Basin should be described and evaluated.
! Ways for municipalities to meet their future water demands should be evaluated.
4-8

4.0 AGENCY PLANNING RECOMMENDATIONS
Platte River Basin
! Water supplies to meet future needs within the
basin should be identified.
! Water resources of the Platte River Basin should
be managed to maximize Wyoming’s use of its
share of the river.
! Groundwater resources of the basin should be
described and evaluated.
! Groundwater usage in the basin should be
managed to prevent aquifer mining.
! Non-tributary groundwater development in the
basin should be supported.
! Proper land management and use should be
promoted to protect water quality.
! Regional water systems should be supported.
! Water storage capacity in the basin should be
increased, including completion of the
Pathfinder Modification Project
Powder/Tongue River Basin
! Groundwater resources of the Powder/Tongue River Basin should be described and
evaluated.
! Groundwater recharge areas should be identified and protected to preserve existing
groundwater quality.
! Groundwater quality data collection should be improved to monitor impacts.
! Careful control of CBM discharge water should be encouraged to reduce the impacts to land
and water resources.
! Existing water supply infrastructure should be maintained and improved to allow local water
systems to meet the demands of population growth.
! Municipalities should be assisted in development of appropriate water supplies to meet
existing and future demands.
! Proper land management and use should be promoted to protect water quality.
Snake/Salt River Basin
! Existing water supply infrastructure should be maintained and improved to allow local water
systems to meet the demands of population growth.
! Projections of future water needs should be made to ensure that sufficient water is available
to meet the anticipated demands.
! Regional water systems should be promoted.
! Groundwater resources of the basin should be described and evaluated.
! Groundwater quality should be monitored to ensure that there is no degradation.
! Proper land management and use should be promoted to protect water quality.
! Water conservation should be promoted within the basin.
4-9

4.0 AGENCY PLANNING RECOMMENDATIONS
Wind/Bighorn River Basin
! Projections of future agricultural and municipal water system needs should be made and
compared to current and future water availability.
! Groundwater resources of the basin should be described and evaluated.
! Current groundwater supplies should be studied to determine safe yield and to prevent
groundwater mining.
! Existing agricultural and municipal water supply infrastructure should be maintained.
! Potential for water conservation in agricultural and municipal water uses should be evaluated.
Statewide Recommendations Developed through the Planning Process
! Municipal and agricultural water infrastructure deferred maintenance needs should be
quantified.
! Long-term climate variability should be considered in river basin planning.
! Watershed planning should be used as a tool in water resource planning and project
development.
! Rehabilitation and improvement of municipal and agricultural water supply infrastructure
should be a priority for assistance.
! Regionalization of municipal and domestic water supplies should be supported to best
manage water resources and protect water supplies.
! The river basin planning process should be continued to assist in development, protection,
and conservation of Wyoming’s water resources.
! The process of describing and evaluating the groundwater resources of the state should be
initiated.
! Collection of surface water data regarding flows and uses should be encouraged to allow
accurate modeling of the river basins.
! Potential new stream gage locations should be identified though the state water planning
process.
! Interconnection between surface water and groundwater should be better defined in the
various river basins.
! Areas where conservation would help Wyoming make more effective use of its water should
be identified.
! Irrigation districts and municipalities should be encouraged to inventory and improve their
infrastructure and to conduct master planning.
4-10

5.0 SUMMARY OF ISSUES AND RECOMMENDATIONS FOR FUTURE RIVER BASIN PLANNING
5.0 SUMMARY OF ISSUES AND RECOMMENDATIONS FOR
FUTURE RIVER BASIN PLANNING
River basin planning is an important function of the Wyoming Water Development Commission
(WWDC) and the State. The purpose of the river basin plans is to define what the state’s water resources
are, how they are being used, and where water is available for development. The plans also project water
demands in the future by evaluating population and economic growth. The planning process is designed
to be dynamic, allowing updates, changes, and adjustments to be made through time. This continuing
planning process implies an evolution and refinement of the plans and process. Preparation of this
Framework Water Plan, Volume II has allowed a review of the initial plans and the planning process.
From the information gathered for this volume, through discussions and inquiries, the following issues
and recommendations have been developed. These issues and recommendations will help guide the first
generation of plan updates and the continuing planning process.
The outreach plans developed during the original river basin planning process should be
continued and improved. The plans should address how best to provide information to the public and
how to involve the public in the planning process. The outreach plans should review the Basin Advisory
Group (BAG) process. The review should strive to adopt new ideas for maintaining the BAGs diversity,
viability and effectiveness.
River basin planning data and information should be presented, as much as possible, in electronic
formats. Plans, studies, and data should be presented through an Internet-based system that allows ease of
access and the ability to link to related sites and data sets. This might include an internet based
Geographic Information System (GIS)/database tool for data and information dissemination.
As part of river basin planning, coordination with local, state, and federal agencies should be
promoted, and agency involvement with BAGs should be encouraged. River basin plans should
incorporate data from a variety of agencies. These data should be integrated into the plans’ digital
products through the use of links to other agency databases. Where appropriate these data should be
incorporated directly into the plans.
River basin planning should consider transitioning from spreadsheet water supply models to more
sophisticated models that allow for more accurate consideration of water availability, uses, storage, and
conservation. Many river basin scale models require large data sets to accurately predict water supplies.
River basin planning will need to consider how best to collect and incorporate such data to allow more
accurate identification of where and in what quantity water is available for use.
River basin planning efforts should incorporate a longer water supply period of record in all
modeling efforts to capture long drought periods and climate variability. River basin plans should use
these data to more accurately project water availability, uses, and needs. Additionally, the plans should
estimate the water available for development under the various compacts and decrees for wet, dry, and
average hydrologic conditions. These efforts should be completed regardless of the model type selected.
Data collection will be needed to support the modeling effort to allow model accuracy.
Future river basin planning efforts and plan updates should focus on problems within the first
plans or areas of substantial change within the basin, and not simply repeat the entire planning process.
Updating every aspect of a basin plan at frequent intervals is not needed or cost-effective. Also
5-1

5.0 SUMMARY OF ISSUES AND RECOMMENDATIONS FOR FUTURE RIVER BASIN PLANNING
performing basin plan updates to capture changes in conditions that will be short-term in nature is not
wise or efficient.
The first round of river basin plan updates should focus on defining and evaluating groundwater
resources within basins. Areas of groundwater and surface water interaction should be defined if
possible. Updates should describe the system improvement and maintenance needs of agriculture and
municipalities within the basins. This could be completed by evaluating current Water Development
Office planning studies and projects. Plan updates should help develop better socioeconomic forecasting
methodologies to account for tourism, recreation, and other nonconsumptive water values and needs.
Data developed through updates should be incorporated into a web-based tool developed through the
Framework water planning process.
5.1 Basin Based Recommendations
Based on our review and understanding of the basin Issues Lists the following general
recommendations are offered for basin and statewide planning:
Northeast River Basins
! Promote proper land management and use to protect and preserve water quality.
! Encourage careful control and management of coal bed natural gas (CBNG) discharge water to
reduce the impacts to land and water.
! Evaluate and describe groundwater resources of the northeast basins.
! Evaluate ways for municipalities to meet their future water demands.
Bear River Basin
! Continue participation in Bear River Regional Water Quality Task Force to protect Wyoming’s
Water Resources.
! Assist in planning for future growth to properly manage and allocate Wyoming’s water resources.
! Continue to work on ways to meet agricultural water needs.
! Evaluate ways to meet the increasing municipal and domestic water demands.
! Evaluate and describe groundwater resources of the Bear River Basin.
Green River Basin
! Identify and pursue water storage opportunities to improve the reliability of the irrigation water
supply on the tributaries of the Upper Green River Basin.
! Obtain accurate data on the water supply and use in the Green River Basin
! Continue to reduce salt loading to the Green River and its tributaries
! Assist in planning for future growth to properly manage and allocate Wyoming’s water resources.
! Plan for future industrial and municipal water needs within the basin.
! Evaluate and describe the groundwater resources of the Green River Basin.
Powder/Tongue River Basins
! Evaluate and describe groundwater resources of the Powder/ Tongue River Basins.
5-2

5.0 SUMMARY OF ISSUES AND RECOMMENDATIONS FOR FUTURE RIVER BASIN PLANNING
! Identify and protect groundwater recharge areas to preserve existing groundwater quality.
! Improve groundwater quality data collection to monitor impacts.
! Encourage careful control of CBNG discharge water to reduce the impacts to land and water
resources.
! Maintain and improve existing water supply infrastructure to allow local water systems to meet
the demands of population growth.
! Help municipalities to develop appropriate water supplies to meet existing and future demands.
! Promote proper land management and use to protect water quality.
Snake/Salt River Basins
! Maintain and improve existing water supply infrastructure to allow local water systems to meet
the demands of population growth.
! Project future water needs to ensure sufficient water is available to meet the anticipated demands.
! Promote Regional water systems.
! Evaluate and describe groundwater resources of the basins.
! Monitor groundwater quality to ensure that there is no degradation.
! Promote proper land management and use to protect water quality.
! Work to promote water conservation within the basins.
! Continue to support Irrigated Agriculture in the Snake / Salt Basin
Wind/Bighorn River Basins
! Project future agricultural and municipal water system needs and compare to current and future
water availability.
! Evaluate and describe groundwater resources of the basins.
! Study current groundwater supplies to determine safe yield and prevent groundwater mining
! Maintain existing agricultural and municipal water supply infrastructure.
! Evaluate the potential for conservation in agricultural and municipal water uses.
Platte River Basin
! Identify water supplies to meet future needs within the basin.
! Manage the water resources of the Platte River Basin to maximize Wyoming’s use of its share of
the river.
! Evaluate and describe groundwater resources of the basin.
! Manage groundwater usage to prevent aquifer mining.
! Support non-tributary groundwater development in the basin.
! Promote proper land management and use to protect water quality.
! Promote Regional Water Systems.
! Increase water storage capacity in the basin with the completion of the Pathfinder Modification
Project
State Wide Recommendations
! Quantify municipal and agricultural water infrastructure deferred maintenance needs.
! Consider long-term climate variability in river basin planning.
5-3

5.0 SUMMARY OF ISSUES AND RECOMMENDATIONS FOR FUTURE RIVER BASIN PLANNING
! Use watershed planning as a tool in water resource planning and project development.
! Assist with rehabilitation and improvement of municipal and agricultural water supply
infrastructure.
! Support regionalization of municipal and domestic water supplies to best manage water resources
and protect water supplies.
! Continue the river basin planning process to assist in development, protection and conservation of
Wyoming’s water resources.
! Initiate the process of describing and evaluating the groundwater resources of the state.
! Encourage collection of surface water data regarding flows and uses to allow accurate modeling
of the river basins.
5-4

Appendix A
EXECUTIVE SUMMARIES AND BAG ISSUES LISTS

BEAR RIVER BASIN

Bear River Basin Water Plan
Executive Summary
September, 2001
Prepared for the
Wyoming Water
Development Commission
L eo n a r d Ric e En g in eer s, In c .

Basin Planning Process
Wyoming is undertaking pro-active statewide basin planning activities to represent changing
conditions since the planning efforts in the late 1960s and early 1970's resulted in the publication
of the Wyoming Framework Water Plan. The Framework Water Plan consisted of summaries of
current water conditions and planning projections for six of the seven major river basins in
Wyoming; the Bear River basin was not included in the Framework Plan. Due to technology
constraints in the early 1970's, the data, mapping, and analyses tools used in developing the
Framework Plan could not be easily updated to reflect changing conditions or new data.
The 1996 legislature directed the Wyoming Water Development Commission (WWDC) and the
State Engineer's Office (SEO) to prepare a recommendation for updating the 1973 Framework
Water Plan. The recommendation concluded that the planning process should accomplish the
following three main objectives:
1. Develop basin plans with the participation of local interest groups.
2. Provide decision makers with current, defensible data to allow them to manage water
resources for the benefit of all the state's citizens. Provide access to the progress, data, and
results of the basin plans in a variety of formats for use by state agencies and Wyoming
citizens, including access via the Internet.
3. Develop basin plans, using contemporary water resources data and tools, that quantify
existing surface and ground water uses and identify potential future uses.
This Bear River Basin Water Plan Report, summarized in this document, is one of the results of
the application of these objectives to the Bear River Basin. The Bear River Basin Water Plan
and supporting documents, data, and models are available from the Wyoming State Water Plan
Web Site (http://waterplan.state.wy.us/), or directly from the WWDC.
Background
The Bear River headwaters are in the Uinta Mountains in Utah. The Bear River enters Wyoming
flowing north through Evanston and into Woodruff Narrows Reservoir. Just downstream of
Woodruff Narrows it flows into Utah and then re-enters Wyoming south of Cokeville. The flow
is increased greatly by the Smith’s Fork River before it enters Idaho, flowing west near the town
of Border. As shown in Figure 1, the Bear River then heads north through Idaho, loops back
south, re-enters Utah, and discharges into the Great Salt Lake. The flow in the Bear River is
allocated between Wyoming, Utah, and Idaho based on diversions and storage defined in the
Bear River Compact. Agriculture accounts for the largest water use in the Wyoming portion of
the basin. Surface and ground water are used to irrigate over 60,000 acres of crop land.
Bear Executive Summary 1 of 12 September 2001

Figure 1
Bear River Basin
Bear Executive Summary 2 of 12 September 2001

The Bear River Compact divides the Bear River Basin into three main divisions. Two of these
divisions are partially within Wyoming. The Upper Division includes portions of Wyoming and
Utah that are upstream of Pixley Dam, located in Wyoming south of the town of Cokeville. The
Central Division includes portions of Wyoming and Idaho between Pixley Dam and Stewart
Dam in Idaho. Much of the information provided in this document is organized by these
divisions.
Approach
The Bear River Basin planning effort met the following four major objectives, which are each
summarized in separate subsequent sections:
Results
The Basin Water Use Profile task determined and quantified the current surface and
ground water uses within the basin (Section 3).
The Basin Water Quality Profile task determined the current surface and ground water
quality within the basin (Section 4).
The Available Water Determination task identified surface and ground water available
for future basin water development (Section 5).
The Demand Projections and Future Water Use Opportunities task identified likely
uses, quantities, and opportunities to meet future water demands in the basin. (Section 6)
Basin Water Use Profile
The total basin water consumed in Wyoming due to human influence include the following
categories:
!
!
!
Agriculture. Agricultural use includes both surface water diverted or ground water
pumped for use in irrigating crops, and water used by cattle and sheep. There are 40,400
and 23,500 irrigated acres in the Upper and Central Divisions of Wyoming respectively.
In the Upper Division, approximately 99 percent of the irrigated acreage is meadow
grass. Only about 1 percent is planted in alfalfa. In the Central Division, about 86
percent is meadow grass, with the remaining planted in alfalfa and small grains.
Municipal and Domestic. Municipal and domestic use includes surface water diverted or
ground water pumped for distribution by the City of Evanston and the Town of
Cokeville. In addition, it includes domestic ground water use by individual households
not connected to public water systems.
Industrial. Industrial use includes commercial or industrial water use by entities not
connected to public water systems.
Bear Executive Summary 3 of 12 September 2001

!
!
!
Environmental. Environmental use includes water used to create and maintain wetlands
and wildlife habitat, water used to maintain minimum fishery pools in reservoirs, and
water designated to maintain minimum flows for fisheries in streams.
Recreational. Recreational use includes water used to maintain minimum recreation
pools in reservoirs and water designated to maintain minimum flows in streams for
boating or aesthetic purposes.
Reservoir Evaporation. Reservoir evaporation is a water “loss” that would not occur in
the absence of reservoirs, therefore is considered a consumptive use of water due to the
influence of humans.
The current total basin consumptive use in Wyoming is approximately 102,000 acre-feet per
year. Figure 1 shows the total basin consumptive use by type. It should be noted that although
water is diverted to Cokeville Meadows National Wildlife Refuge (environmental use), it is used
to irrigate crops historically grown in the area. Therefore, that consumptive use is included in
the agricultural category. Water is used for recreational purposes in the basin both to maintain
minimum reservoir pools and to maintain minimum streamflows. However, this use is nonconsumptive.
1,540 acre-feet
(1.5%)
Figure 1
Annual Basin Consumptive Use by
Industrial Use
400 acre-feet
Reservoir
(0.4%)
Evaporation
5,280 acre-feet
(5.2%)
Municipal and Domestic Use
Environmental Use
negligible
Recreational Use
negligible
Agricultural Use
94,583 acre-feet
(92.9%)
Bear Executive Summary 4 of 12 September 2001

Figure 2 shows the average annual basin consumptive use by supply source.
Figure 2
Annual Basin Consumptive Use by
Ground Water
2,530 acre-feet
Surface Water
99,273 acre-feet
Basin Water Quality Profile
Surface Water
Total Dissolved Solids (TDS) is a measure of the total amount of dissolved salts in water.
Although TDS does not provide the entire picture on water quality, it is easily measured and is,
therefore, frequently used as an indicator of overall water quality. The following summarizes the
surface water quality analysis for the Bear River Basin:
!
!
!
!
The primary use of water in this basin is for agricultural purposes, and when the data
available for Total Dissolved Solids (TDS) and other parameters are compared to
standards set for agricultural use, concentrations are consistently below the water quality
limits.
With the exception of Twin Creek, all the gages have TDS concentrations consistently
below the TDS standards set for drinking water limits.
Concentrations of TDS vary with flow. During low flow seasons, such as late summer
months and non-irrigation seasons, the concentration of TDS increases, likely because a
larger percent of the flow is agricultural and municipal return flows. During high flow
seasons, such as late spring and early summer months, TDS concentrations decrease.
Throughout the study period for the USGS water quality gages, no significant increase
has been seen in TDS concentrations.
Bear Executive Summary 5 of 12 September 2001

Ground Water
Unlike continuous surface water quality gages, ground water quality measurements in the Bear
River Basin have generally not been taken at the same location over time. Therefore, it is
difficult to make assessments regarding trends in ground water quality. However, general
conclusions can be made regarding the ground water quality of the aquifer that is tributary to the
Bear River as follows:
!
!
!
Ground water quality is generally good, but may exceed domestic standards in the area of
the basin around Twin Creek
Ground water quality usually meets agricultural and livestock standards
Ground water quality is generally better in the southern (upstream) portion of the basin
Available Water Determination
Surface Water
Surface water availability varies with hydrology and location in the basin. Spreadsheet Models
were developed to represent historic dry, normal, and wet year hydrology in the basin. Current
water use and Bear River Compact limitations were superimposed on the hydrology to estimate
surface water availability in the basin. Figure 3 shows the total available monthly flow in the
Upper Division for dry, normal, and wet hydrologic years.
160,000
Figure 3
Upper Division Available Monthly Streamflow during Dry, Normal, and
Wet Hydrologic Years
140,000
120,000
Available Flow (acre-feet)
100,000
80,000
60,000
40,000
20,000
0
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Dry Normal Wet
Bear Executive Summary 6 of 12 September 2001

The following summarizes the Upper Division available flows:
!
!
!
!
!
During a dry year, water for diversion and future permanent use in the Upper Division is
available only during the non-irrigation season. This total amount is approximately
27,000 acre-feet per year.
Approximately 142,000 acre-feet per year of water is available during normal hydrologic
conditions. About 60 percent of this flow is available during the high runoff months of
May and June.
Approximately 325,000 acre-feet per year of water is available during a wet hydrologic
year, with over 60 percent of the flow available during May and June.
For all three hydrologic conditions, the available flows during the non-irrigation season
are limited to the Bear River mainstem between the confluence with Sulphur Creek and
Pixley Dam (includes portions of Utah).
For all three hydrologic conditions, the available flows during the irrigation season are
limited to the Bear River mainstem between Evanston and Woodruff Narrows Reservoir.
Figure 4 shows the total available monthly flow in the Central Division for dry, normal, and wet
hydrologic years.
250,000
Figure 4
Central Division Available Monthly Streamflow during Dry, Normal,
and Wet Hydrologic Years
200,000
Available Flow (acre-feet)
150,000
100,000
50,000
0
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Dry Normal Wet
Bear Executive Summary 7 of 12 September 2001

The following summarizes the Central Division available flows:
!
!
!
!
During a dry year, there is no additional water available for development in the Central
Division.
Approximately 190,000 acre-feet per year of water is available during normal hydrologic
conditions. This water is only available from March through July, with the majority
available during the high run-off months of May and June. Much of this flow originates
from "spills" over Pixley Dam, and may not be available if future Upper Division
allocations under the compact are completely consumed.
Approximately 500,000 acre-feet per year of water is available during a wet hydrologic
year, with over 60 percent of the flow available during May and June. Again, much of
this flow originates from "spills" over Pixley Dam, and may not be available if future
Upper Division allocations under the compact are completely consumed.
For normal and wet hydrologic conditions, there is available flow during the nonirrigation
season on both Smith’s Fork and the Bear River mainstem.
Ground Water
Current ground water withdrawal estimates indicate that, on average, less than 3,000 acre-feet
per year of ground water is currently used in the Bear River Basin. The majority of this use is
from the Alluvial Aquifer, defined as the aquifer within the Bear River alluvium. Future
development of this aquifer could provide additional water to meet increased demands, however
there are limitations and restrictions to additional depletions outlined in the Bear River Compact.
These restrictions consider withdrawals from the Alluvial Aquifer to be similar to river
withdrawals.
It is estimated that additional development of up to 14,000 acre-feet per year in the Bedrock
Aquifers, defined as aquifers outside the Bear River alluvium, would be sustainable. Well
development in the Bedrock Aquifers needs to be studied in greater detail to determine the
impact on Bear River flows and the extent to which compact restrictions may apply.
Demand Projections
Demand projections were developed for two scenarios using an economic based approach. The
planning horizon was 30 years, therefore growth was estimated through the year 2030. The High
Case Scenario incorporates the most growth in key economic sectors that is reasonably likely to
occur over the forecast horizon. This scenario incorporates the aggressive assumption that each
of the key sectors will achieve its highest likely growth at the same time, providing an upper
bound for water planning purposes. The Low Case Scenario incorporates the lowest growth
reasonably likely to occur in key economic sectors. This provides the lower bound for planning
purposes.
Bear Executive Summary 8 of 12 September 2001

High Case Scenario
Total basin water diversion requirements are projected to increase by about seven percent from
year 2000 to year 2030 under the High Case Scenario. Under normal hydrologic conditions, this
amounts to about 21,400 acre-feet; under dry hydrologic year conditions the increase would be
about 29,000 acre-feet. The following summarizes uses for the High Case Scenario:
!
!
!
!
!
!
Total agricultural water demand grows slightly over the planning period, whether
measured in terms of diversions or consumptive use. Despite a lack of growth in the
sector, agriculture continues to comprise the vast majority of total water demand under
the High Case Scenario; agriculture is responsible for 97 percent of total water diverted
and 94 percent of total consumptive use in the year 2030.
Municipal water demand almost doubles over the 30-year planning period, however, it
remains a relatively small sector, accounting for only 2.6 percent of total water
diversions, and 4.8 percent of total consumptive use within the Basin.
Water demand is projected to more than double in all municipal sectors in Evanston,
however, water demand in Cokeville remains almost constant over the planning period.
This is because the projected population growth of Cokeville is offset by the assumption
that per capita water demand will decline sharply due to the implementation of usage
based water rates in the town during the planning period.
Rural domestic water demand is projected to almost double over the next 30 years, due in
large part to the projected population growth around the Evanston area.
Water demand within the industrial sector is not projected to change substantially over
the projection period.
Changes in overall water demand over the 30-year planning period are relatively small
because of the continued domination of the agricultural sector.
Low Case Scenario
Total water diversion requirements under the low economic forecasting scenario are projected to
be slightly lower in 2030 than they were in 2000. The following summarizes uses for the Low
Case Scenario:
!
Total water demand in the agricultural sector declines over the projection period by about
6 percent. The decline in livestock water demand directly reflects the impacts of a
change in BLM grazing policy and the implementation of the Cokeville Meadows
Wildlife Refuge.
Bear Executive Summary 9 of 12 September 2001

!
!
!
!
The environmental sector line item included in the low scenario specifically refers to the
wetland water requirements within the Cokeville Meadows Wildlife Refuge. If the
refuge is fully implemented, water impoundments will likely be made in order to
augment existing waterfowl habitat area.
In the municipal sector, the modest decline in both diversions and consumptive use is the
direct result of two factors: constant population levels and the anticipated implementation
of a usage based water rates system in Cokeville.
The most significant change under the low scenario was the complete elimination of any
industrial water demand within the Basin. This result is reflective of the assumed
extraction of all remaining recoverable natural gas reserves within the Basin during the
30-year projection period.
Changes in overall water demand over the 30-year time horizon are relatively small
because of the continued domination of the agricultural sector.
TABLE 1
Bear River Basin – Wyoming
Current and Projected Annual Water Diversion Demand
(Acre Feet)
Current 2030 Low Scenario 2030 High Scenario
Demand Type
Normal
Demand Year
High Demand
Year
Normal
Demand Year
High Demand
Year
Normal
Demand Year
High Demand
Year
Agriculture 295,196 419,713 277,627 394,736 312,188 443,850
Municipal 4,446 5,030 4,342 4,938 8,364 9,550
Rural Domestic 500 500 504 504 959 959
Industrial 459 680 - - 494 731
Environmental - - 15,305 21,434 - -
TOTALS 300,601 425,923 297,778 421,614 322,005 455,091
Future Water Use Opportunities
Economic Development Opportunities
Wyoming’s approach to basin planning includes the identification and prioritization of future
water use opportunities. This process involved extensive interviews with representatives from
government, larger industrial entities, agriculture, energy, and tourism. These interviews and
Bear Executive Summary 10 of 12 September 2001

investigations did not result in the identification of any specific economic plans or opportunities
beyond the growth scenarios presented herein. No listing of future opportunities, therefore, is
included as part of this Bear River Basin Plan. As opportunity(s) are identified in the future, the
spreadsheet modeling software created as part of the planning effort will we a valuable tool in
ascertaining the feasibility and/or impacts of individual projects.
Conservation Opportunities
The state of Wyoming is supportive of water conservation as an environmentally responsible
policy. In many cases, water conservation offers a direct economic benefit to water users. In the
case of municipalities, for example, reduced water consumption translates into reduced treatment
and operational costs. In the case of irrigation, one would expect agricultural users to benefit
through increased overall water availability due to conservation measures. However, in the Bear
River Basin, this is not necessarily the case. Current land application practices in the Upper
Division almost exclusively involve flood irrigation. As a result of this practice, the Bear River
is recharged, with up to 50% of the return flows re-entering the streams later in the irrigation
season when divertible flows would normally be much less. This in-ground storage actually
benefits water users late in the irrigation season. Irrigation conservation may be more
economically attractive in the Central Division where Water Emergency conditions typically
occur earlier in the season.
Storage Opportunities
Projected future water supply demands will require supplemental water from storage or from
ground water, since there is essentially no available water for diversion during dry years.
There were essentially 8 dry years in the 28 year historical study period. This represents
approximately 3 out of every 10 years in which there are no additional divertible flows in excess
of current water rights. There are virtually no available flows in either division during dry year
periods, in any months. To guarantee a firm yield beyond existing allocations during these dry
year periods, additional storage reservoirs would be required.
Based on the normal year hydrology, the best development plan would be the construction of
storage up to the yield available during these years - 150,000 and 190,000 acre-feet in either the
Upper or Central Divisions respectively. There would be the need to carry over some storage to
guard against dry year yields (zero) and to take into account losses from the reservoir(s). The
firm yield, therefore, would be on the order of 75,000 acre-feet in the Upper Division and 95,000
acre-feet in the Central Division. The State of Wyoming has a remaining allocation of
approximately 4318 acre-feet of compact storage rights under the original 1958 Bear River
Compact. Additional storage development in excess of 4318 acre-feet would be subordinate to
the requirement that storage cannot take place in the Upper or Central Division when the water
surface elevation of Bear Lake drops below 5911 feet.
There have been several previous studies directed toward the feasibility and capacity of various
reservoir sites within the Bear River Basin. The potential for future reservoir construction was
Bear Executive Summary 11 of 12 September 2001

presented to the Basin Advisory Group (BAG) on several occasions for discussion. The
consensus of the BAG was to not pursue or list storage as an option at this time. This feeling
was, in part, due to economic concerns (cost vs. benefit) and environmental permitting concerns.
None-the-less, storage is a viable option in the future as the need and/or economic desirability of
storage changes.
Near the completion of the planning study, water users from the Cokeville area approached the
Wyoming Water Development Commission to initiate discussions relative to developing storage
on the Smith’s Fork. The Smith’s Fork appears to have excellent storage potential from a
hydrologic standpoint. There is a permit pending for the Ferney Glade Reservoir site on the
Smith’s Fork, which was filed in 1960 for 5201 acre-feet. A larger reservoir would likely
require the partnership and participation of downstream states.
Continued Planning Process
Wyoming’s Water Planning Process is not intended to provide a directive for the implementation
of future water development, but rather to provide the basic information needed to address water
issues that arise in the future. One of the most important products of the planning process is the
collection, storage in a useable format, and understanding of basic water resource and water use
data in the Bear River Basin.
The Bear River Basin planning effort has created an informed group of citizens interested in
water issues. The members of the basin advisory group have chosen to continue to meet three
times a year to discuss water issues. The Bear River Basin Water Plan Report will provide the
framework for discussions and planning efforts related to current water use, projected water use,
compact issues, and other regulatory issues in the Basin.
Previous Wyoming water planning documents provided useful snapshots in time, but were often
outdated within a few years. The advance of computer and Internet technology will help assure
that the Statewide Water Planning Process will remain current and accessible to the citizens of
Wyoming. The WWDC intends to update each basin water plan approximately every five years.
Bear Executive Summary 12 of 12 September 2001

1 of 2
Issues identified in the Bear River Basin
Category
Issues
Water Allocation - Bear River Compact Administration
- Storage
- Smith's Fork
- Compact Allocation
- Town of Bear River
- Measuring device installation - info available on Web
- Conveyance loss study (UW Water Research Program)
- USCOE Flood Study
- Groundwater - only compact with groundwater specifically in allocations
- WWDC Small Water Projects
- Spring development with NRCS in Cokeville
Water Quality - Joint 3 State Water Quality Committee affiliated with Bear River Commission
- Water Quality Task Force - Bear Lake Regional Commission staffs this
- responsible for reviewing stateline standards for compatibility
- Upper Bear River Watershed Plan (in lieu of TMDL)
- DEQ 319 Projects
- Bridger Creek, Thomas Fork
- AML Phosphate Mine
Future Demands and Growth - Town of Bear River
- Cokeville spring developments
- Smith's Fork (storage)
- Wildlife Refuge land acquisition
- Woodruff Narrows Reservoir deliveries
- Compact tie to elevation of Bear Lake
- Downstream growth pressures on Bear River (Washakie Reservoir in Utah)
Habitat, Wildlife and Fisheries - Instream flow applications
- Bonneville cutthroat trout petitioned
- habitat improvements
- upgrading measuring devices
- Smith's Fork Reservoir project
- Wildlife Refuge
- Evanston river restoration
- Upper Bear River Watershed plan

2 of 2
Issues identified in the Bear River Basin
Economics - Town of Bear River
- WWDC Level I Study - Smith's Fork
- Wind generation - Evanston diversifying
- Wildlife Refuge development and related tourism impacts
- WWDC Small Water Project program
NOTE: Per the meeting held 11-7-2005, the wording in blue are some of the issues that the BAG decided they wanted to have taken forward to the
Framework consultant

GREEN RIVER BASIN

Executive Summary
Green River Basin Water Plan
February, 2001
Prepared for:
Wyoming Water Development Commission
Basin Planning Program
States West Water Resources Corporation

Executive Summary, Green River Basin Water Plan
Project Scope
The Green River Basin Water Planning Process document is second of two River Basin
Plans compiled under initial efforts of the Wyoming Water Development Commission,
and authorized by the Wyoming Legislature in 1999. The plan for the Bear River Basin
is the first. Subsequent years will see plans developed for the northeast part of the State
(Little Bighorn, Tongue, Powder, Little Missouri, Belle Fourche, Cheyenne, and Niobrara
Rivers), Big Horn/Wind, Snake/Salt, and Platte River Basins. It is the express desire of
the program to revisit and update the basin planning documents every five years.
This planning document presents current and proposed (estimated) future uses of water in
Wyoming’s Green River Basin. Uses to be inventoried include agricultural, municipal,
industrial, environmental, and recreation. Surface and groundwater uses are both
described as is overall water quality. Given current uses, the availability of surface and
ground water to meet estimated future requirements is analyzed. To lay the groundwork
for future water development, a review of the current institutional and legal framework
facing such projects is presented. Finally, thoughts are given to guide implementation of
the water planning process.
The Final Report is designed to present findings in enough detail to explain the overall
plan without deluging the reader in technical minutiae. Separate Technical Memoranda
provide technical details, methods, and selected references.
Basin Description
The Green River Basin consists of lands in Wyoming, Colorado, and Utah that drain to
the Green River, the largest tributary of the Colorado River. The Wyoming portion of the
Basin comprises nearly 25,000 square miles in Sweetwater, Sublette, Carbon, Lincoln,
Uinta, and small areas in Fremont and Teton counties. For purposes of this plan, the
Great Divide Basin is included, though this region does not contribute any run-off to the
Green River.
Climate throughout the Basin varies, but generally follows the pattern of a high desert
region. Precipitation data are available for about a dozen Weather Service stations in the
Basin for the past 30 years. Various climatological factors combine to create a relatively
short growing season throughout the Basin.
In addition to Flaming Gorge Reservoir, major water bodies include the Green River
Lakes, New Fork Lake, Willow Lake, Fremont Lake, Halfmoon Lake, Burnt Lake,
Boulder Lake, Big Sandy Reservoir, Eden Valley Reservoir, Fontenelle Reservoir, and
numerous high mountain lakes in the Wind River Range in the central and eastern part of
the Basin. In the western part of the Basin are Viva Naughton and Kemmerer No. 1
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Executive Summary, Green River Basin Water Plan
Reservoirs. To the south, Meeks Cabin and Stateline Reservoirs serve various Wyoming
users, although Stateline is located entirely in Utah.
Major tributaries to the Green River include the New Fork, East Fork, and Big and Little
Sandy Rivers in the northeast; the Little Snake River in the southeast; the Hams Fork,
Blacks Fork and Henrys Fork of the Green in the southwest; and the Piney, LaBarge,
Fontenelle, Cottonwood and Horse Creeks (among others) in the north and west.
Colorado River Management
The Green River of Wyoming is the major tributary to the Colorado River, one of the
most physically controlled and institutionally managed rivers in the world. It drains the
largest river basin in the United States save the Mississippi. Prone to flooding and
needed for irrigation, the river came under the control of several major dams in the 20 th
century. Management of these structures, of the water in the river, and the distribution of
the water for various needs has resulted in a regulatory and legal framework now known
as the “Law of the River.”
Of the several documents which comprise the Law, Wyoming’s ability to develop and
consumptively use water in the Green River Basin primarily is constrained by the two
interstate Compacts, the Colorado River Compact of 1922, and the Upper Colorado
River Basin Compact of 1948.
The States of the Upper Basin (Colorado, Utah, New Mexico, and Wyoming) allowed
development to begin by establishing a division of the water through the Upper Colorado
River Basin Compact, which followed the format of and was subject to the provisions of
the original Colorado River Compact. This Compact among the upper basin states
apportioned 50,000 acre-feet of consumptive use to Arizona (which contains a small
amount of area tributary to the Colorado above the Compact point at Lee Ferry) and to
the remaining states the following percentages of the total quantity available for use each
year in the upper basin as provided by the 1922 Compact (after deduction of Arizona’s
share):
! Colorado = 51.75 percent;
! Utah = 23.00 percent;
! New Mexico = 11.25 percent;
! Wyoming = 14.00 percent.
Using these percentages and best-case assumptions, the probable long-term available
water supply for Wyoming from the Green River and its tributaries is 833,000 acre-feet
per year.
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Executive Summary, Green River Basin Water Plan
Water Storage
The Basin contains approximately 212,000 acre-feet of storage primarily devoted to
supplemental irrigation supply. Some irrigated areas are well served by one or several
reservoirs above them while others are devoid of storage of any size. The following chart
depicts the relative availability of storage for irrigation in the sub-basins:
Relative Storage Availability for Agricultural Uses
(Derived as Acre-feet of Storage per Acre of Irrigated Land)
Upper Green
Little Snake
New Fork
Henrys Fork
Blacks Fork
Hams Fork
Big Sandy
Current Water Use Summary
The major water uses are summarized in the following chart:
Summary of Current Water Uses
Environmental Use
0.3%
Municipal
1%
City of Cheyenne
2%
Evaporation –
In State
5%
Evaporation –
Main Stem
14%
Industrial
11%
Total Use =
611,700
Acre-feet per Year
Agricultural
67%
Page 3 of 11

Executive Summary, Green River Basin Water Plan
Agricultural Use
The Green River Basin of Wyoming is primarily a producer of forage for livestock. By
far the most common use of irrigation is in the growth of grass hay for harvest and
pasture. Alfalfa is grown in areas where the growing season and water supplies allow.
Small grains and cash crops are very limited in extent.
Water supply and growing season are the factors most often given for the predominance
of grasses under irrigation. In this sense, irrigated agriculture is tied very closely to the
livestock industry because the only viable use for the hay is as forage. Typically the
forage is used by the producers’ herds although some is disposed through local sale or
export from the Basin.
The depletion of water by irrigation is estimated, in general terms, using available water
supply, the consumptive demand of the crops irrigated and the number of irrigated acres
in the Basin. These depletions, or “consumptive use” estimates are useful for evaluating
the overall use of water in the Basin relative to Compact allotments, the location of use
relative to water supplies, and the relative amounts of the varying uses when growth is
considered.
Municipal and Domestic Use
Nine municipalities in the Basin obtain their primary water supply from surface water
while six municipalities use groundwater supplies. Domestic use is typically provided by
ground water and is on the order of 1,900 to 3,900 acre-feet per year in the Green River
Basin.
Industrial Use
Power plants including the Jim Bridger and Naughton Power Plants are the largest
industrial water users in the Basin. Soda Ash Production is the second largest. Industrial
groundwater use, largely a by-product of the petroleum or coal extraction process, is a
small percentage of overall industrial water use.
Recreational Use
Recreational uses, generally non-consumptive uses, include boating, fishing, waterfowl
hunting, and maintenance of wild and scenic rivers. In addition, information regarding
visitation to the Fort Bridger Historic Site indicates that one in four visitors intend some
water-based recreation at that location or elsewhere during their trip.
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Executive Summary, Green River Basin Water Plan
Environmental Use
Environmental Uses are also typically non-consumptive and include instream flows and
reservoir bypasses, minimum reservoir pools and channel maintenance flows,
maintenance of wetlands, riparian habitat, and other wildlife habitat, and direct wildlife
consumption.
Evaporation
Evaporation from reservoirs constructed by man is a consumptive use associated with the
beneficial use of water for other purposes and is counted as part of Wyoming’s allocation
under the Upper Colorado River Basin Compact.
Available Surface Water
For each Green River sub-basin, three models were developed, reflecting each of three
hydrologic conditions: dry, normal, and wet year water supply. Streamflow, consumptive
use, diversions, irrigation return flow patterns, and reservoir conditions are the basic
input data to the model. Model output includes a comparison of historical and estimated
diversions, and streamflow at specific model nodes in the Green River Basin for each of
the dry, normal, and wet hydrologic conditions.
The results denote physical availability over and above existing uses, which is to be
distinguished from legal or permitted availability; the models do not explicitly account
for water rights, appropriations, or Compact allocations, nor is the model operated based
on these legal constraints. Physical availability of water is the important first step in
assessing the viability of any future water development project.
The tabulations show annual available supply at the bottom of the system for each basin
as follows:
Annual Available Supply (acre-feet per year)
Basin Dry Condition Normal Condition Wet Condition
Little Snake 189,000 449,000 665,000
Henrys Fork 23,000 60,000 125,000
Blacks Fork 101,000 229,000 422,000
Green River 620,000 1,269,000 1,924,000
Input to the models can be modified in order to estimate impacts associated with various
water projects.
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Executive Summary, Green River Basin Water Plan
Available Ground Water
Groundwater resources of the Basin are largely undeveloped at this time. Consequently,
sparse information is available to evaluate groundwater characteristics and development
prospects in the Basin.
Ground water is principally used for drinking water supplies and industrial use. The
majority of the supplies are developed from Quaternary and Tertiary aquifers. Current
groundwater use within the Greater Green River Basin is estimated at 5,300 to 7,200
acre-feet per year
The majority of the study area is underlain by rocks that are host to several important
aquifers, including the Frontier aquifer (western part of the Basin), the Mesaverde
aquifer, and the Tertiary aquifer system.
Various estimates of groundwater recharge by precipitation derive a potential basin
groundwater yield between 50,000 and 100,000 acre-feet per year. Thus, there is no
evidence to suggest over-development of the principal aquifer systems. It may be
concluded that there is significant potential for additional development of these aquifer
systems, with little risk of depleting this resource.
There are many factors that may affect future development and availability of
groundwater resources. In the case of alluvial aquifers, any future development of
groundwater resources may be expected to have a direct and near-immediate impact on
the adjacent rivers and streams within the alluvial system. The quality of water extracted
as a by-product of potential coal bed methane (CBM) development in the Basin is
reported to be significantly worse than in the Powder River Basin. Limitations imposed
by Interstate Compact on the quality of water discharged to the Green River may require
that the co-produced water be treated or reinjected. The impacts of the added costs of
treatment or reinjection are unclear, but may render some CBM projects uneconomical.
At this time, it appears unlikely that the level of development of CBM resources in the
Greater Green River Basin will match the levels of development anticipated in the
Powder River Basin given current market and environmental conditions.
Demand Projections Summary
For assessing the need for water into the future, this plan has developed estimates of
water demand for each major use category out to year 2030. A summary of all projected
uses is provided in the following table. Values are acre-feet per year:
Page 6 of 11

Executive Summary, Green River Basin Water Plan
Type of
Surface Water
Use
Current
Projected Growth Scenario
(Normal Year)
Use Low Moderate High
Municipal 6,500 6,600 8,100 10,100
City of Cheyenne 14,400 22,700 22,700 22,700
Industrial 66,500 78,000 106,400 166,300
Agricultural 401,000 408,000 423,000 438,000
Evaporation (in-State) 32,800 32,800 32,800 32,800
Recreation
non-consumptive
Environmental 2,000 10,000 17,000 24,000
Total 523,200 558,100 610,000 693,900
Percent of Compact
Allocation
Main-Stem
Evaporation Charge
(Full Development)
63% 67% 73% 83%
88,500 72,800 72,800 72,800
Grand Total 611,700 630,900 682,800 766,700
Percent of Compact
73% 76% 82% 92%
Allocation
(assumed allocation = 833,000 acre-feet per year)
Agricultural Use Projections
Future demands for additional irrigation water in the Green River Basin are largely
dependent upon factors that might either increase the returns that Basin irrigators receive
from irrigation or reduce the cost to them of developing new storage. Possibilities for
increasing economic returns to irrigated agriculture in the Basin include diversifying
cropping patterns into higher valued crops, the possibility that hay prices may rise to the
point that it would be profitable to export hay from the Basin to other domestic markets,
the possibility that cattle prices may rise significantly over the next 30 years, and an
increase in the amount of financial assistance available to producers for reservoir
construction from State and federal agencies.
The types of hay expected to be in high demand in the future are alfalfa for dairies and
Timothy hay for horses. If future market prices for these crops stabilize at levels of well
over $100 per ton, it may become practical for Green River Basin producers to develop
additional storage and expand production of these crops for export markets.
Municipal/Domestic Use Projections
Three methods of producing population forecasts were evaluated. The Division of
Economic Analysis of the Wyoming Department of Administration and Information
produces population forecasts based upon time series data from which growth rates are
Page 7 of 11

Executive Summary, Green River Basin Water Plan
derived from variables such as population, sales tax collections, and school enrollments.
Second, the United States Census Bureau periodically produces population forecasts
using mortality rates, fertility rates, and migration patterns. A third set of population
projections assumes that the area would experience a total population increase during the
period from 2000 to 2030 that is of the same magnitude that occurred during the 30-year
period from 1960 to 1990.
Projections were made using high, moderate, and low growth scenarios. Current
municipal and domestic water consumption rates were applied to population projections
to estimate a potential increase of future municipal and domestic use of 40 to 60 percent.
Industrial Use Projections
The largest industrial water uses in the Basin involve electric power generation and soda
ash production. Future water needs for electric power production in the Basin will be
largely determined by how electric utilities in the Basin and elsewhere in the west
respond to growing demands and various actions and proposals to deregulate the
industry. Scenarios for possible industry responses to deregulation are not easily
developed. Similarly, future growth prospects for the soda ash industry are largely
dictated by the ability of Wyoming producers to capture an increasing share of the
international market in the face of volatile international economic conditions and the
protective tariffs imposed by some foreign countries.
Under a low growth scenario, surface water requirements for large industrial water users
may increase by as little as 17 percent. A moderate growth scenario projects a reasonably
foreseeable increase of 68 percent, while a high growth scenario projects an increase of
150 percent.
Recreation Use Projections
According to the Wyoming Game and Fish Department, the Green River could provide
an annual supply of nearly 1,122,800 activity days of lake and reservoir fishing
opportunities. When contrasted with the current rate of about 485,000 activity days of
use annually, there is presently no apparent shortage of still water angling opportunities
in the Basin.
A different conclusion applies to the Basin’s stream fisheries. In 1988, the Wyoming
Game and Fish Department estimated a total supply of about 411,000 angler days of
stream fishing opportunities available in the Basin, but only about 213,000 angler days of
this supply were in areas where public access was guaranteed. That figure contrasts with
a current estimated annual use of about 300,000 angler days of activity, and projected
demands in the range of 327,000 to 566,000 angler days of activity by the year 2030.
These estimates indicate that the Basin’s stream fisheries are already at capacity, and will
come under increasing pressure in the future as its population increases and tourism
related fishing pressure grows.
Page 8 of 11

Executive Summary, Green River Basin Water Plan
Environmental Use Projections
Environmental water requirements are not necessarily related to changes in population or
tourism in the Basin. Instead, environmental water requirements are at least partially a
function of human desires concerning the type of environment in which people want to
live. These desires are expressed through environmental programs and regulations
promulgated by elected representatives at the state and federal levels. Thus, future
environmental water requirements in the Green River Basin will be determined, at least
partially, by existing and new legislation dealing with environmental issues at the state
and federal levels, and how that legislation is implemented by federal and state agencies.
Wyoming’s instream flow statutes recognize such non-consumptive flows not only
contribute to aesthetic character and biological diversity of the Basin, they also support
recreational fisheries that are important to Basin residents and to the Basin’s economy.
Five reservoirs in the Basin have “fish” or “fish and wildlife” uses listed in their
permitting documents: Big Sandy, Boulder, Flaming Gorge, Fontenelle, and High
Savery. Given the current federal regulatory environment and the desires of the public to
maintain and enhance recreational fisheries in the Basin, it is likely that any additional
storage developed in the future will have a provision of minimum reservoir pools for fish
and wildlife purposes.
Water Development Needs and Opportunities
Considering consumptive uses of water, only the agriculture sector experiences current
shortages. Predictably, these shortages are in areas not already served by storage to any
significant extent. Unfortunately, the main reason these shortages exist is that agriculture
is the economic sector least able to afford the high cost of storage construction. This is
especially true for those operators focused upon raising forage instead of cash crops, to
provide late season supplemental supplies.
Therefore, the general direction taken for recommending future use opportunities focused
largely on providing supplemental irrigation supplies. Multiple use opportunities were
also considered because the effects of the various projects on environmental and
recreational values (including funding) are very important and can result in otherwise
similar projects being viewed quite differently.
Nine previously completed planning studies, new project ideas suggested by Basin
Advisory Group (BAG) members, and an initial screening of clearly unfeasible or
unlikely candidates provided over 45 projects to review for potential application to
current and future needs. Groundwater development and conservation opportunities,
such as conversion to sprinkler irrigation or canal rehabilitation, were also evaluated on a
regional (sub-basin) basis.
Based upon comments received during BAG meetings, review of previously published
criteria and questionnaire results, and the Scope of Services, a procedure for screening
opportunities for future water use was developed. The procedure included a prioritization
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Executive Summary, Green River Basin Water Plan
based on need, and evaluative criteria based on favorability. Projects were initially
prioritized according to the following schedule:
Priority
Description
1 Rehabilitation projects that preserve existing uses and economic
dependencies.
2 Projects that rectify existing demands/needs/shortages.
3 Projects that meet projected future demands/needs/shortages
4 Trans-basin diversions of water that enhance in-state uses.
Six criteria under each of these priorities aim to present an overall picture of the
favorability of a project. These include factors ranking water availability, financial
feasibility, public acceptance, number of sponsors/beneficiaries/participants,
legal/institutional constraints, and environmental/recreational benefits.
The Green River Basin Plan provides detailed strategies for coping with institutional and
financial constraints on water project development.
Future Water Plan Directives
This document is intended to be used as a reference for citizens of the State of Wyoming
and agency personnel to understand the current state of water use and development in
Wyoming’s Greater Green River Basin. It will be available to legislators as background
material when evaluating future water development funding decisions. It can be referred
to for assistance in establishing purpose and need for future water development project
work. Agency personnel will, upon critical review and with experience from its use, find
areas to be more closely evaluated in subsequent updates.
The Wyoming Water Development Commission, the state revolving fund for water
treatment facilities, federal assistance through the USDA Rural Development Program
and various conservation programs (e.g. the Conservation Reserve Program and Wildlife
Habitat Incentives Program) all provide water development assistance for municipalities,
irrigation districts, and individuals to perform necessary and valuable work that they
otherwise could not afford. Because water development in the form of water treatment
improvements and environmental enhancements are desirable goals, these programs are
vital to the overall quality of life in the Basin.
Water development has become difficult and costly. However, if a project proponent has
a need for water, patience, and financial resources, the federal permitting process can be
successfully completed. Wyoming must maintain its resolve to develop its water
resources to meet the needs of its citizens.
Page 10 of 11

Executive Summary, Green River Basin Water Plan
The publication of the Green River Basin Plan should foster discussion among water
users and state officials relative to water development in the Green River Basin in
Wyoming. The plan concludes that Wyoming has water to develop in the Basin. The
water can be used for future municipal and industrial growth. There are existing
agricultural water demands that could be met with the water.
As long as Wyoming has water to develop in the Green River Basin, there will be debate
regarding the sale or lease of water to downstream interests. Storage water or other
supplies that can be delivered on demand may offer revenue potential for the State.
The Green River Basin Plan is an important step towards identifying and achieving
Wyoming goals in the Green River Basin. It is important to update and maintain the
Green River Basin Plan or it will simply be a glimpse of the status of the water use at the
end of the twentieth century. In order to improve on the plan, additional data will be
necessary, and the understanding of existing water use must be maintained or improved.
Page 11 of 11

Issues identified in the Green River Basin
1 of 3
Issues
Current Status
Agriculture Additional Storage - Church Reservoir Study
- Upper Green Study
- BLM Stock reservoirs (small water projects)
- Viva Naughton Level II Phase I and II Studies
- Middle Piney Reservoir New Project application
- Eden Valley Pipeline Level III Project
- Boulter Reservoir Level II
- Weather Modification Study
- Water Value Study
- Green River Groundwater Recharge and Alternate Storage Study
- High Savery Reservoir
- Salinity Control Project
Groundwater - Green River Groundwater Recharge and Alternate Storage Study
- WWDC Small Water Projects
- Sweetwater Conservation District - 14 wells and 1 pipeline
- Little Snake River Conservation District - 8 spring developments and 2 solar platforms
- Wamsutter well
Economic Development - Water Value Study
- Upper Green Joint Powers Board
Downstream claims/ Instate - Colorado River Compact Administration Report (Mike Purcell)
Compacts and Decrees - 3 public meetings
- SEO budget request for Colorado River Coordinator position
Downstream - Upper Colorado Compact Commission
- 7 States discussion
- California quantification
- Lake Powell/Lake Meade storage equity
- Additional supply needs for city of Las Vegas
- Quantification of supply under Compact
Water Quality Instate - Big Sandy - pipeline
- WWDC Small Water Projects
- Sweetwater Conservation District - 14 wells and 1 pipeline
- Little Snake River Conservation District - 8 spring developments and 2 solar platforms
- SEO Atlantic Rim Water Management Study (2006 Legislation)
- 205 (j) projects
Basin-wide - Salinity Control Forum
- Ft. Bridger area salinity review

Issues identified in the Green River Basin
2 of 3
Water Quality (cont.) - 303 (d) (DEQ)
- Fremont Lake monitoring (municipal supply for Pinedale) in conjunction w/Lakeside Lodge Expansion EA
- CBNG development
Municipal/Domestic - Baggs
- Wamsutter
- Bridger Valley
- Green River/Rock Springs Master Plan
- Metering requirements
Water Conservation/Re-use - Green River Supply Canal Level II and Level III projects
- Little Snake System
- Eden/Farson (Big Sandy Salinity Project)
- Eden/Farson pipeline
- Green River/Rock Springs - water re-use on parks and golf courses
- Municipal metering requirements
- CBNG development (water discharge, storage, reinjection)
Non-consumptive/aesthetic uses - Pinedale desire for instream flow through town
- Water Plan - listing of instream flow applications
- High Savery Reservoir - fish pool
- Maintaining overall watershed/environmental health (wetlands)
- CBNG development
Water Development - (revisit entire list)
- Fontenelle water sales
- quantification of remaining compact allocation
- BORs management of water in Fontenelle
Federal Involvement/Regulations - High Savery - fish pool - Colorado River cutthroat
Lawsuits - Endangered Fish Recovery Program
- Yampa Programmatic Environmental Impact Statement (EIS)
- Energy development (leasing of Federal lands/minerals rights)
- Marketing of water out of Fontenelle (Bureau of Reclamation)
- CBNG development
Recreation - Green River water park
- Storage
- Flaming Gorge
- Viva Naughton
- Fontenelle
- High Savery

Issues identified in the Green River Basin
3 of 3
Recreation (cont.) - BLM stock reservoirs (Old Steve Adams #5)
- Purchase of ag lands for "non-traditional" uses
- other recreational uses on reservoirs and streams in basin (fishing, floating, bird watching, etc.)
Industry/Minerals/Manufacturing - Trona
- Jim Bridger
- Kemmerer need for reliable water supply
- Coalbed Natural Gas (CBNG), Oil and Gas development (Jonah)
- oil shale development
- Simplot phosphates
- synthetic-based fuel from coal (coal liquefaction)
- enlargement of Jim Bridger plant (possible enl. of Naughton and others)
- Gov's proposed energy corridor (water needs)
- reinjection of produced water below 7500' (Pinedale Anticline and Jonah field)
Drought Mitigation/Flood Control - Dry year leasing
- Temporary water right transfers
- Drought updates from State Climatologist
- Winter snowpack augmentation
- Bureau of Reclamation operation plans
Water Rights - Pinedale - Instream flow through town
- Transbasin diversions
- Subdivision administration
- SEO - increased penalty to those taking water without permit
- Ongoing Compact work
- Mapping project (SEO) and consumptive use analysis (CO River Compact Administration Project)
- increased measuring devices and accuracy in diversions
Implementation - Upper Green River Joint Powers Board
- Water Value Study
- revisit list concerning projects and studies that have been completed
- Groundwater in Water Plan updates
NOTE: Revisions to list were made per comments and suggestions from BAG members at meeting held on 11-8-2005

NORTHEAST RIVER BASIN

Northeast Wyoming River Basins Plan
Executive Summary
Prepared for:
Wyoming Water Development Commission
Basin Planning Program
Prepared by:
HKM Engineering Inc.
Lord Consulting
Watts and Associates
February 2002
Page 1 of 11

Northeast Wyoming River Basins Plan
Executive Summary
Prepared for:
Wyoming Water Development Commission
Basin Planning Program
Prepared by:
HKM Engineering Inc.
Lord Consulting
Watts and Associates
February 2002
Page 2 of 11

Executive Summary
Northeast Wyoming River Basins Plan
Project Scope
The Northeast Wyoming River Basins Plan document is one of four River Basin Plans thus far
completed by the Wyoming Water Development Commission as authorized by the Wyoming
Legislature in 1999. The plans for the Bear River Basin and Green River Basin were completed
in 2001, and the plan for the Powder/Tongue River Basin is being completed concurrently with
the Northeast Wyoming River Basins Plan. The Wind/Big Horn River Basin and the Snake/Salt
River Basin plans were initiated in 2002 and the plan for the North Platte River will commence
in the near future. It is the express desire of the program to revisit and update the basin planning
documents every five years.
This planning document presents current and projected future uses of water in Wyoming’s
Northeast Wyoming River Basins. Uses inventoried and analyzed in this plan include
agricultural, municipal, industrial, environmental, and recreational. Surface and ground water
uses are both described, as is overall water quality. Given current uses, the availability of
surface water and ground water to meet estimated future requirements is analyzed. The current
institutional and legal framework of water development and management is presented.
The primary products of this planning study are technical memoranda prepared for the large
number of topics addressed in the plan. These memoranda provide detailed descriptions of the
data collected, source references, analyses performed, tools developed, and the results of each
investigation required to fully explore the water resources within the planning area. The intent of
this Executive Summary, and the associated Final Report, is to describe the planning study in
sufficient detail for the reader to gain a general understanding of the investigations that were
performed and the results of those investigations. For detailed information on a specific topic the
reader is directed to the technical memorandum prepared for that topic.
Basin Description
The study area of the Northeast Wyoming River Basins Plan includes the drainages of the Little
Missouri River, Belle Fourche River, Cheyenne River, and Niobrara River. These river basins
encompass all or part of Campbell, Crook, Weston, Converse, and Niobrara counties as well as
minor parts of Natrona and Goshen counties in northeast Wyoming. The planning area is shown
on Figure 1.
Climate throughout the Basin varies, but generally follows the pattern of a high desert region.
Annual precipitation in the range of 13 to 15 inches is the norm for the majority of the planning
area.
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Northeast Wyoming River Basins Plan – Executive Summary
2 of 12

Northeast Wyoming River Basins Plan – Executive Summary
The major rivers and streams in the study area include the following:
! Little Missouri River Basin – Little Missouri River
! Belle Fourche River Basin – Belle Fourche River, Redwater Creek, Beaver Creek,
Blacktail Creek, Lytle Creek, Miller Creek, Inyan Kara Creek, Donkey Creek, and Arch
Creek
! Cheyenne River Basin – Cheyenne River, Antelope Creek, Lightning Creek, Lance
Creek, Beaver Creek, and Stockade Beaver Creek
! Niobrara River Basin – Niobrara River
The largest storage facility developed in the Northeast Wyoming Planning area is Keyhole
Reservoir on the Belle Fourche River. Other reservoirs having significant capacity include
Gillette Reservoir on Donkey Creek, Betty No. 1 Reservoir on Antelope Creek, Spencer
Reservoir on Stockade Beaver Creek, Klodt Reservoir on Mush Creek, and Tract 37 Reservoir
on the North Fork of the Little Missouri River.
Water Law and Interstate Compacts
The Wyoming constitution establishes water in the state to be the property of the state.
Consequently, all development and management of water resources in Wyoming is governed by
the water laws embodied in the Constitution and Statutes. These water laws are recognized as
inviolate in the river basin planning program.
Interstate compacts controling the development and use of water in the study area include the
Belle Fourche River Compact of 1943 and the Upper Niobrara River Compact of 1962.
Compacts have also been developed for the Cheyenne River and the Little Missouri River, but
these agreements have yet to be fully ratified.
The Belle Fourche River Compact of 1943 divides the water between Wyoming and South
Dakota. The compact recognizes all rights in Wyoming existing as of the date of the compact,
and permits Wyoming unlimited use for stock water reservoirs not exceeding twenty acre-feet in
capacity. Wyoming is allowed to deplete the flow of the Belle Fourche River under the
conditions existing as of the date of the Compact by an additional 10%. No reservoir constructed
subsequent to the date of the compact solely to utilize the water allocated to Wyoming shall have
a capacity greater than 1,000 acre-feet.
The Upper Niobrara River Compact of 1962 between Wyoming and Nebraska provides that
stock water reservoirs not larger than twenty acre-feet capacity in Wyoming shall not be
restricted. No restrictions are placed on diversion or storage of water in Wyoming except on the
main stem of the Niobrara River east of Range 62 West and on Van Tassel Creek south of
Section 27, Township 32 North, Range 60 West. In this area direct diversions are regulated on
an interstate priority basis with lands in Nebraska west of Range 55 West, and storage reservoirs
with priority dates prior to August 1, 1957, may store water only during the period of October 1
to June 1, while storage reservoirs with priority dates after August 1, 1957, may store a
maximum of 500 acre-feet in any water year with dates of storage limited to the period of
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Northeast Wyoming River Basins Plan – Executive Summary
October 1 to May 1. Ground water development is recognized to be a significant factor and the
compact provides for investigation of this resource and possible apportionment at a later date.
Agricultural Water Use
Irrigated agriculture in the planning area is primarily associated with forage production for the
livestock industry. Ranchers depend on irrigated cropland to provide winter feed and summer
grazing for their stock. Alfalfa, grass hay, and pasture grass are the dominant crops grown in the
planning area. Lesser amounts of small grains and corn are also produced. In total, 77,350 acres
of land are actively irrigated in the planning area. Of this total, 13,036 acres are served from
ground water and the remainder is served from surface water supplies.
The depletion of water by irrigation is primarily dependent on the number of acres irrigated, the
crop water demands, and the amount of water available to meet these demands. Surface water
depletions for wet, normal, and dry years total 71,000 acre-feet, 69,000 acre-feet, and 65,000
acre-feet respectively. Ground water depletions for wet, normal, and dry years total 17,000 acrefeet,
17,000 acre-feet, and 11,000 acre-feet respectively.
Municipal and Domestic Water Use
There are thirty-three public water supply entities in the planning area, consisting of incorporated
municipalities, districts, and privately owned water systems. These entities consume
approximately 9,100 acre-feet of ground water per year. Domestic use is also satisfied by
ground water and is on the order of 2,100 to 3,600 acre-feet per year.
Industrial Water Use
Industrial water use in the Northeast Wyoming River Basins consists of conventional oil and gas
production, coalbed methane development, electric power generation, coal mining, and oil
refining. These uses deplete approximately 50,700 acre-feet of ground water per year.
Recreational Water Use
Recreational uses associated with the water resources of the Northeast Wyoming River Basins
include boating, fishing, and waterfowl hunting. Although these uses are generally nonconsumptive,
water-based recreation is enhanced through minimum flow releases from
reservoirs, minimum pool levels maintained in reservoirs, and instream flow water rights
established on streams. Keyhole Reservoir, the largest standing water recreation attraction in the
Northeast Wyoming River Basins, supports skiing, fishing, swimming, boating, and camping.
Environmental Water Use
Environmental uses of water in the Northeast Wyoming River Basins are largely nonconsumptive.
Environmental use topics addressed in this planning study include water
administration (minimum flow releases, minimum pool maintenance, and instream flow water
rights), environmental concerns associated with water produced by coal bed methane
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Northeast Wyoming River Basins Plan – Executive Summary
development, and wetland mapping. Concerns expressed by environmental organizations are
also presented in the basin plan.
Reservoir Evaporation
The majority of water use from storage reservoirs within the Northeast Wyoming River Basins is
for irrigation. Evaporation from these storage reservoirs constitutes another consumptive use of
water within the planning area. Evaporation from the 6 key storage facilities (generally larger
than 1,000 acre-feet) totals 14,400 acre-feet annually.
Evaporation from stock ponds is considered to be a relatively minor contributor to total water
consumption in most river basins in the State. However, given the relative scarcity of surface
water in the planning area, together with the large number of stock ponds that exist, the
accumulative evaporation loss from these ponds is relatively significant. The total annual
evaporation loss from stock ponds is 6,300 acre-feet from 16,600 stock ponds.
Current Water Use Summary
The current water uses in the planning area are summarized as follows:
Water Use
Surface
Water
Dry Normal Wet
Ground
Water
Surface
Water
(AF/Year)
Ground
Water
Surface
Water
Ground
Water
Agricultural 65,000 11,000 69,000 17,000 71,000 17,000
Municipal --- 9,100 --- 9,100 --- 9,100
Domestic --- 3,600 --- 3,600 --- 3,600
Industrial
Recreation
Environmental
Evaporation
Oil & Gas 1 --- 46,000 --- 46,000 --- 46,000
Other 2 --- 4,700 --- 4,700 --- 4,700
Key
Reservoirs
Non-consumptive
Non-consumptive
14,000 --- 14,000 --- 14,000 ---
Stock Ponds 6,300 --- 6,300 --- 6,300 ---
TOTAL 85,300 74,400 89,300 80,400 91,300 80,400
Notes: 1. Includes conventional oil and gas and CBM production water.
2. Includes electricity generation, coal mining, and oil refining.
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Northeast Wyoming River Basins Plan – Executive Summary
Available Surface Water
The determination of available surface water was broken down into the following seven tasks for
this study:
1. Compilation of Historic Streamflow Records
2. Selection of an appropriate Study Period
3. Extension of Records to represent the entire study period
4. Estimating Natural Flow at Ungaged Model Nodes
5. Determining Streamflows during Wet, Normal, and Dry years
6. Development and Calibration of Spreadsheet Models
7. Determination of Available Surface Water
Records from 34 USGS and SEO streamflow gages were compiled and then extended where
records were missing, to provide estimates of streamflow for each month, of each year during the
1970 to 1999 study period. These recorded and estimated streamflows were used to determine
the amount of streamflow at additional ungaged locations needed for the water availability
models. The annual streamflows were ranked and the years were divided into three hydrologic
conditions (dry years, normal years, and wet years). The average flows for each of these three
conditions are primary inputs to the models.
Water availability spreadsheet models were developed for the following four sub-basins within
the Northeast Wyoming River Basins planning area:
! Belle Fourche River sub-basin
! Redwater Creek sub-basin
! Beaver Creek sub-basin
! Cheyenne River sub-basin
Three models were developed for each sub-basin to represent each of the three hydrologic
conditions. The models each represent one calendar year of flows, on a monthly time step.
Streamflow, estimated actual diversions, full supply diversions, irrigation returns, and reservoir
storage conditions are the basic input data to the models. For all of these data, average values
drawn from the dry, normal, or wet years of the study period were computed for use in the
spreadsheets.
The models do not explicitly account for water rights nor are the models operated based on these
legal constraints. Further, the models do not associate supplemental reservoir releases to the
specific water users. However, by calibrating the models to historical streamflows at gaged
locations, the models can be used to generally represent existing operations. Model inputs can
then be modified to estimate the impacts associated with potential future water projects.
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Northeast Wyoming River Basins Plan – Executive Summary
The total annual flow, physically available in excess of current Wyoming water demands, is
summarized as follows:
Hydrologic Condition
Subbasin Wet Years Normal Years Dry Years
Redwater Creek 34,000 26,000 17,000
Beaver Creek 30,000 20,000 14,000
Cheyenne River 103,000 31,000 5,000
Belle Fourche River 151,000 71,000 13,000
The Belle Fourche Compact of 1943 allocates 10% of the unappropriated waters, as of the date
of the compact, in the Belle Fourche River to the State of Wyoming, with the remaining 90%
being allocated to South Dakota.
Wyoming’s apportionment of the Belle Fourche River under the three hydrologic conditions
(wet, normal, and dry years) is summarized as follows:
Average Annual Apportionment (AF)
Hydrologic Condition
Belle Fourche Redwater
River
Creek
Total
Wet Years 15,600 3,300 18,900
Normal Years 7,400 2,400 9,800
Dry Years 1,100 1,400 2,500
Available Ground Water
The objectives of this element of the study were as follows:
1. Inventory and catalog the Wyoming State Engineer's Office (SEO) ground water permit
database for various categories of ground water uses in the planning area, and incorporate the
information into GIS data themes.
2. Inventory and document existing published data on ground water studies and ground water
planning documents for the planning area.
3. Summarize existing information on aquifers with regards to location, storage, yield and
development potential within the planning area.
4. Summarize the potential effects that ground water development might have on the ground
water and surface water systems in the basins within the planning area.
5. Characterize coalbed methane development and its short and long-term effects on ground
water and surface water supplies within the river basins of the planning area.
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Northeast Wyoming River Basins Plan – Executive Summary
The information developed through this study provides a starting point for site specific ground
water investigations.
The significance of ground water in the planning area is demonstrated by the 15,793 active ground
water permits (as of December 31, 2000) within the planning area. Because of the dynamic nature of
coalbed methane (CBM) development, the inventory of permitted CBM wells was updated to reflect
data as of December 31, 2001. The number of permits for each use category are summarized below:
! 308 Permitted active agricultural wells with production rates greater than 49 gpm
! 76 Permitted active municipal wells with production rates greater than 49 gpm
! 608 Permitted active industrial and miscellaneous wells with production rates greater
than 49 gpm
! 2,760 Active permitted domestic wells
! 6,756 Active permitted stock wells
! 5,285 Permitted coalbed methane wells (6,657 by December 31,2001)
The six major aquifer systems within the planning area are (oldest to youngest): 1) Madison
Aquifer System; 2) Dakota Aquifer System; 3) Fox Hills/Lance Aquifer System; 4) Fort
Union/Wasatch Aquifer System; 5) Tertiary Aquifer System; and 6) Quaternary Alluvial Aquifer
System.
General conclusions regarding ground water development potential of four of these five major
aquifer systems are summarized below:
! The Madison Aquifer System may have the most development potential for high yield
wells on a sustained basis. Drilling depths and water quality may constrain development
at specific locations within the planning area.
! The Fox Hills/Lance Aquifer System may have local potential for development of wells
with low to moderate yields. The possible high fluoride content in water from this
system might influence the desirability of use for a municipal/public supply without
provision for treatment or special management.
! The Fort Union/Wasatch Aquifer System is utilized for most uses in the planning area.
The Wyodak-Anderson coal and hydraulically interconnected aquifers of the Aquifer
System will be heavily impacted by ground water withdrawals in and near coalbed
methane development. The water co-produced with coalbed methane may provide an
opportunity for utilization, depending on location, quality and nature of potential use.
! Aquifers in the Quaternary Alluvial Aquifer System may have local development
potential if induced infiltration of surface water can be tolerated.
Out of total of 15,793 active ground water permits inventoried in December 31, 2000 for the
Basin Plan, 10,508 of the permits were for WWDC categories other than coalbed methane
development (agricultural, municipal, industrial, domestic and stock). Possible impacts of further
development for these uses could include:
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Northeast Wyoming River Basins Plan – Executive Summary
! Depletion of surface water that is interconnected with aquifer systems. The principal
aquifer systems of concern with respect to this impact include the Madison and the
Quaternary Alluvial Aquifer Systems.
! Interference problems between wells and / or aquifer depletion problems related to
domestic and stock well densities.
! Aquifer depletion where aquifers are used for secondary oil and gas recovery operations.
! Water quality impacts due to oil and gas drilling and recovery operations and leakage
through inadequate or failed plugging of production wells.
A total of 6,657 permitted coalbed methane wells (December 31, 2001) were identified. Possible
impacts of coalbed methane development include:
! The dewatering of aquifers and the lowering of water levels and yields in production
wells located in the vicinity of coalbed methane development.
! Methane seepage into wells and structures in the proximity of coalbed methane
development that could pose a health and safety hazard to residents.
! Increased infiltration of water from coalbed methane production into shallow alluvial
ground water systems that could aggravate subsurface structure problems.
! Increased infiltration of water from coalbed methane production into shallow ground
water systems that could impact the quality and use of ground water from shallow
systems.
! Impacts to surface coal mining operations.
Possible surface water related impacts that have been identified could include:
! Change in drainage characteristics from ephemeral to perennial. This could result in an
increase in the erosion potential and sedimentation problems in receiving drainages.
! Increased flooding potential in receiving drainages. Higher flows could also impede
landowner access associated with their operations.
! Alteration of the chemical characteristics of receiving surface waters due to coalbed
methane generated water. This could include a change due to increased salinity and
sodium content that could impact irrigation practices and the utilization of surface water
for irrigation.
Irrigation Use Projections
To assess future water needs in the Northeast Wyoming River Basins, projections of future water
demands were developed for major water use categories through the year 2030. The projected
consumptive water use was determined for low, moderate, and high growth scenarios.
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Northeast Wyoming River Basins Plan – Executive Summary
Future irrigation water use depends upon factors such as crop and livestock prices, the cost of
developing new water storage and delivery systems, and compact limitations. The low growth
scenario projects no significant changes in those factors, and thus no future increase in surface
irrigation water use. The moderate and high growth scenarios project moderate increases in
surface irrigation water use based upon projected increases in crop and livestock prices and the
possibility of increased state assistance for developing new irrigation water supplies.
Consumptive use of surface water could rise from a current level of 69,500 acre-feet annually to
as much as 75,700 acre-feet by the year 2030. Groundwater irrigation depletions, which currently
total 16,900 acre-feet of water annually, could rise to as much as 20,800 acre-feet by that date.
Municipal and Domestic Use Projections
Municipal and domestic water needs in Northeast Wyoming are satistified by groundwater.
Future demands for municipal and domestic water are closely tied to the future population levels
in the planning area. Three population-forecasting methods were used to develop low, moderate,
and high growth population projections for communities and rural areas through the year 2030.
Based upon these projections, municipal and domestic water use is expected to grow from a
current level of 12,700 acre-feet annually to 14,600 acre-feet annually by 2030 for the low
growth scenario. For the moderate and high growth scenarios, the increases are to 16,100 and
18,200 acre-feet respectively. The high growth scenario projection corresponds to a 43 percent
increase in water use over the planning horizon.
Industrial Use Projections
There are no large industrial users of surface water in the planning area. Industries such as
electric power production, oil and gas development, and mining use all make use of
groundwater. Industrial usage of groundwater is expected to increase significantly in the future
with the construction of additional coal-fired electric generating facilities, as well as coalconversion
facilities designed to produce synthetic fuels and/or increase the heat content of coal.
For the low growth scenario, such developments are expected to increase the industrial use of
groundwater from a current level of 900 acre-feet annually to 3,700 acre-feet by 2030. For the
moderate and high growth scenarios, industrial water demand is expected to increase to between
9,100 and 17,300 acre-feet annually by 2030.
Recreation Use Projections
Fishing is the predominant water-based recreational activity in Northeast Wyoming, and angers
currently engage in approximately 65,000 activity days of fishing each year. Projections
developed for this study indicate fishing demand is expected to increase to between 81,000 and
121,000 activity days annually by the year 2030. Northeast Wyoming has limited stream fishery
resources and only one large reservoir, Keyhole, to supply recreational opportunities. These
limited resources will come under increasing pressure in the future as recreational demand
increases as a result of population growth and increases in tourism.
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Northeast Wyoming River Basins Plan – Executive Summary
Environmental Use Projections
Environmental water requirements are not directly related to changes in population or tourism,
but instead reflect human desires concerning the type of environment in which people want to
live. These desires are reflected in environmental programs and regulations promulgated by
elected representatives at the local, state and federal levels. Examples include Wyoming’s
instream flow statues and minimum reservoir pools dedicated to fish and wildlife enhancement.
While generally non-consumptive, environmental needs can conflict with consumptive water
demands in some situations. Northeast Wyoming has only limited water resources to meet both
consumptive and non-consumptive water demands.
Compact Considerations
Wyoming’s use of surface waters from the Belle Fourche River is subject to limitation by
interstate compact. This limitation constrains Wyoming’s ability to develop additional surface
water resources to meet future needs in Northeast Wyoming.
Demand Projections Summary
The projected consumptive use of surface water and ground water, for the low, moderate, and
high growth scenarios in the following two tables.
Summary of Current and Projected Surface Water and Ground Water Uses
Use
Surface
Water
Projected Use by Growth Scenario
(Acre-feet/Yr.)
Current Low Moderate High
Ground
Water
Surface
Water
Ground
Water
Surface
Water
Ground
Water
Surface
Water
Ground
Water
Municipal/Domestic 0 12,700 0 14,600 0 16,100 0 18,200
Industrial 1 negligible 900 negligible 3,700 negligible 9,100 negligible 17,300
Irrigation 69,500 16,900 69,500 16,900 72,800 18,900 75,700 20,800
Evaporation 23,500 23,500 23,500 23,500
Recreational
Environmental
(non-consumptive)
(not estimated)
Total 93,000 30,500 93,000 35,200 96,300 44,100 99,200 56,300
Note 1: Excludes oil, gas, and mining uses.
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Northeast Wyoming River Basins Plan – Executive Summary
Future Water Use Opportunities
This river basin plan quantifies water resources available for development and use and identifies
current and projected future water needs in the Northeast Wyoming River Basins. The
concluding task of this study is to identify future water use opportunities that can be
implemented to satisfy the water demands in the Little Missouri River, Belle Fourche River,
Cheyenne River, and Niobrara River Basins in Wyoming. The list of potential water use
opportunities provided is intended to assist individuals and organizations in finding ways to meet
their specific needs.
To further assist the users of this list in identifying potential opportunities to satisfy their
demands, a methodology is presented that can be employed to evaluate a specific opportunity on
the list relative to similar and related opportunities. The suggested methodology evaluates
opportunities according to the likelihood they are desirable, functional, and capable of receiving
the support required for development. By using the list of future water use opportunities and
employing the evaluation methodology, individuals and organizations will have “a place to start”
in their investigation.
The procedure used to complete this task consisted of four steps:
1. Develop screening criteria to evaluate future water use opportunities – the six screening
criteria are: 1) water availability; 2) financial feasibility; 3) number of sponsors,
beneficiaries, and participants; 4) public acceptance; 5) legal and institutional concerns; and,
6) environmental and recreational benefits.
2. Develop a long-list of future water use opportunities – this list was compiled from published
reports and information provided by the members of the Basin Advisory Group (BAG).
3. Develop a short-list of opportunities – projects and opportunities on the long-list were
screened to eliminate projects considered to have little likelihood of development.
4. Evaluate the opportunities on the short-list – the projects advancing to the short-list were
categorized by location and type, then evaluated using the criteria developed in Step 1 of the
process.
Legal and institutional constraints that need to be addressed in water management and
development were identified and described in the planning study.
The success of a water development project is also dependent on the ability of the source to meet
the water quality needs of the proposed uses. In addition, the project itself must protect existing
and potential uses of waters of the State. As a part of this river basin planning process a
description of the water quality character of the Northeast Wyoming River Basins was
developed. The plan also describes contemporary water quality programs initiated to protect and
enhance the quality of surface water in the planning area. Finally, the primary issues related to
the quality of water in the planning area are detailed in industrial, agricultural, and municipal
categories.
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Issues identified in the Northeast Basin
1 of 2
Category Issues Activities/Projects
Related Lands - Noxious weeds
- Streambank erosion
- Private land rights
Funding - Funding for implementation
- Private, state, federal - Who?
Water Development - Agriculture Crook Co. Reservoir Study
- Recreation
- Municipal
Water Rights - Water quantity (adjudicated rights vs. normal streamflow)
- Current use, adjudicated and historical
- Private property water rights
- State law water rights
- Protecting existing water rights
- Compact issues - Belle Fourche River
- Keep "Wyoming" water in Wyoming
Underground Water - Industrial Gillette Groundwater
- Urban Pine Haven, Canyon, Sunset, Moorcroft, Wright
- Agricultural
Regulatory - Clean Water Act, water quality, TMDLs
- Wetlands
- Endangered species
- Groundwater permitting process
- Forest management, or lack thereof, effecting water quality
- Governmental taking of water and/or land
- Corps of Engineers
- EPA
- BOR
- BLM
- Source point pollution problems
- WY DEQ
- Stream classification
- Conflicting government goals with private owners caught in the middle

Issues identified in the Northeast Basin
Category Issues Activities/Projects
2 of 2
Quality - Sewer discharge
- Non-point source pollution
- Streambank erosion
- Underground irrigation wells
- Maintaining water quality for present and future uses
- Water quality of each stream/river should be determined by a
statistically proven testing method
- Coalbed methane water impact down river - quantity and quality
- Timber, mining, oil and gas
Uses - Develop for maximum recreational use
- Boating and fishing
- Water resources uses
- Coalbed methane water impact down river - quantity and quality
- Fisheries
- Swimming
- Wildlife
- Timber, mining, oil and gas
- Flood control
Quantity - Wasting water discharging without beneficial use
- Water quantity (adjudicated rights vs. normal streamflow)
- Instream flow
- Underground irrigation wells
- Draft on aquifers, all uses
- Coalbed methane water impact down river - quantity and quality
- Timber, mining, oil and gas
- Flood control
Economic Development - Roads, new and existing
- Subdivisions
- Industrial
Conservation - Surface water
- Groundwater
- Recycling
- Research
NOTE: Revisions were made to this list per comments from BAG members at meeting held 12-8-2005

PLATTE RIVER BASIN

TABLE OF CONTENTS
E X E C U T I V E S U M M A R Y , P L A T T E R I V E R B A S I N W A T E R P L A N . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Project Scope...................................................................................................................................................................1
Basin description .............................................................................................................................................................2
Platte River Water Management......................................................................................................................................3
Platte River Basin Plan Water Atlas Educational Tool ...................................................................................................4
Agricultural Water Use....................................................................................................................................................5
Federal Irrigation Projects in Wyoming’s Platte River Basin .........................................................................................5
Municipal and Domestic Water Use................................................................................................................................5
Industrial Water Use........................................................................................................................................................6
Recreational Water Use...................................................................................................................................................6
Environmental water use .................................................................................................................................................7
Water Use From Storage .................................................................................................................................................7
Current Water Use Summary ..........................................................................................................................................7
Available Surface Water..................................................................................................................................................8
Available Groundwater ...................................................................................................................................................8
Demand Projections Summary ........................................................................................................................................9
Projected Annual Water Demands – High Scenerio........................................................................................................10
Projected Annual Water Demands – Low Scenario ........................................................................................................11
Projected Annual Water Demands – Mid Scenario .........................................................................................................12
Future Water Use Opportunities......................................................................................................................................13
Future Water Plan Directives ..........................................................................................................................................14

E X E C U T I V E S U M M A R Y
E X ECUTIVE SUMMARY:
P L A T T E RIVER BASIN WATER PLAN
P R O J E C T S C O P E
The Platte River Basin Plan is the seventh and last
of a series of Wyoming river basin plans prepared
for the Wyoming Water Development Commission
(WWDC). Wyoming previously completed water
plans for the Bear River Basin, Green River Basin,
Northeast Wyoming River Basin, Powder/Tongue
River Basin, Snake/Salt River Basin, and
Wind/Bighorn River Basin.
The Wyoming State Engineer’s Office (SEO) and
the Wyoming Water Planning Program completed
The Wyoming Framework Water Plan in 1973.
The intent of the 1973 document was to provide a
“basis upon which to launch further water resource
planning.” (Wyoming State Engineer’s Office,
1973) This document addressed water issues in all Wyoming river basins. In 1996, the Wyoming Legislature directed
the WWDC and the SEO to prepare recommendations for updating the 1973 Framework Water Plan. After reviewing
the agencies’ recommendations, the 1999 Wyoming Legislature authorized completion of the Bear River and Green
River Basin Plans and has subsequently authorized completion of the other basin plans listed above, including this
Platte River Basin Plan.
The Wyoming basin planning process is founded on the Prior Appropriation Doctrine and the understanding that the
State of Wyoming should manage its water resources “for the benefit of the citizens of the state.” (Wyoming Water
Development Commission, 2002) Major goals of the basin planning process include:
" Providing accurate, timely Wyoming water information, both to state officials and to the general public
" Maintaining an inventory of water uses
" Assisting Wyoming government officials in developing effective state water policies
" Protecting future water demands
" Keeping Wyoming’s water planning process comparable to those of other western states
" Protecting Wyoming’s water resources from downstream competitors
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P L A T T E R I V E R B A S I N P R O J E C T
The Platte River Basin Plan consists of the following components:
" Technical memoranda containing detailed assessments of specific Platte River Basin water data
" A Geographical Information System (GIS) map-based database containing Platte River Basin water resource
information that has been generated for and during this project
" A “Water Atlas” web-based educational tool that is intended to provide key Platte River Basin Plan information to
the public in a readily-accessible fashion
" A Platte River Basin Plan Report, which contains a summary of information from the other three components of
the project
B A S I N D E S C R I P T I O N
The Platte River Basin encompasses nearly one-quarter of the land area of Wyoming and comprises the southeast
portion of the state. All of Albany, Laramie, and Platte Counties and portions of Carbon, Converse, Fremont, Goshen,
Natrona, Niobrara, Sublette, and Sweetwater Counties are located within the Basin.
The Platte River Basin is part of the Missouri-Mississippi River Basin. The headwaters of the North Platte originate
with streams east of the Continental Divide located in the mountains surrounding North Park in Colorado and the Sierra
Madre and Snowy Range mountains of southern Wyoming. The river flows northerly through central Wyoming and
east on to Nebraska, gathering an average annual run-off of 1.4 million acre-feet. In central Nebraska, the North and
South Platte rivers join to form the Platte River flowing eastward to the Missouri River south of Omaha, Nebraska.
The North Platte River drainage in Wyoming was divided into the seven subbasins for the purposes of basin planning:
" Above Pathfinder Reservoir
" Pathfinder Reservoir to Guernsey Reservoir
" Guernsey Reservoir to State Line
" Horse Creek
" Lower Laramie
" Upper Laramie
" South Platte
Although portions of the drainages for both the North and South Platte Rivers exist in Wyoming, only the North Platte
River flows through the state. The South Platte River drainage in Wyoming consists of headwater streams that drain
into Colorado and Nebraska. The Laramie River is a major tributary of the North Platte River, which headwaters in
Colorado.
The topography of the Platte River Basin includes valleys, high plains, hills, and mountains with elevations up to
12,013 feet above mean sea level at Medicine Bow Peak of the Medicine Bow Mountains. The lowest point of
elevation in the Platte River Basin in Wyoming is 4,025 feet above mean sea level and is located on the North Platte
River where the river crosses the Wyoming-Nebraska State Line.
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E X E C U T I V E S U M M A R Y
Precipitation and streamflows throughout the Platte River Basin follow topography and geomorphology. A large
portion of the Basin within Wyoming receives an average of 8-12 inches of precipitation annually. Downstream
portions of the Basin typically receive an average of 12-16 inches of precipitation annually. The heaviest precipitation
in the Basin falls over the mountain ranges. Precipitation increases with elevation and can exceed 60 inches a year at
the highest points in the Basin.
P L A T T E R I V E R W A T E R M A N A G E M E N T
The Territory of Wyoming was created on July 25, 1868 and shortly thereafter, the first water laws for Wyoming were
drafted. The early laws set the foundation of water law as it exists today by establishing the ideas of priority of
appropriation and stewardship of water resources. In 1890, Wyoming was divided into four water divisions, with
Division One containing the Platte River Basin. The Carey Act was passed in 1894 to promote reclaiming lands in each
of the western states for irrigation and settlement. This prompted investment in water development projects, including
the construction of Wheatland No. 1 (1897) and Wheatland No. 2 (1898) Reservoirs on the Laramie River by the
Wyoming Development Company. Reservoir construction continued through the early 1900’s throughout Division
One and the rest of Wyoming.
The construction of several large reservoirs by the Bureau of Reclamation along the North Platte River in Wyoming
during the first half of the 20th century has had a significant effect on the use and distribution of water in the Basin.
Pathfinder, Seminoe, Kortes, Alcova, Glendo, and Guernsey Reservoir provide storage supplies for federal irrigation
projects serving over 226,000 acres, as well as hydropower generation. Along the Laramie River, major reservoirs
include Wheatland No. 2, Wheatland No. 3, and Grayrocks. All of these reservoirs store water for irrigation.
Irrigation is the largest use of water in the Platte Basin. The apportionment of water between the States of Wyoming,
Colorado, and Nebraska for irrigation use has historically been disputed between the three states. The first interstate
lawsuit regarding the apportionment of water was filed by Wyoming in 1911 against the State of Colorado and its use
of water from the Big Laramie River. Eleven years later, the Supreme Court ruled that priority of appropriation would
be used to apportion waters across state lines since both states recognized that doctrine individually.
With the drought of the 1930’s, Nebraska filed a lawsuit against Wyoming in 1934 claiming that priority water rights in
Nebraska were not being honored due to diversions in Wyoming for junior rights. In its 1945 decree, the Supreme
Court upheld rights in Nebraska and set limitations on appropriations of North Platte water in Wyoming.
Subsequently, Nebraska filed a lawsuit reopening the decree in 1986 that resulted in establishment of the Modified
North Platte Decree in 2001.
In 1997, the States of Colorado, Wyoming, and Nebraska and the U.S. Department of the Interior (DOI) signed the
Cooperative Agreement for Platte River Research and Other Efforts Relating to Endangered Species Habitat Along the
Central Platte River, Nebraska (Cooperative Agreement). The purpose of the Cooperative Agreement is to implement
certain aspects of the U.S. Fish and Wildlife Service’s (USFWS) recovery plans for target species (whooping crane,
piping plover, interior least tern, and the pallid sturgeon) that relate to the habitats of these species. This agreement
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P L A T T E R I V E R B A S I N P R O J E C T
stipulates the development of a Basin-wide program, the Platte River Recovery Implementation Program (PRRIP), to
be implemented following evaluation of the Proposed Alternative and a range of reasonable alternatives in compliance
with the National Environmental Policy Act (NEPA) and the Endangered Species Act (ESA).
The Cooperative Agreement led to the creation of a Governance Committee composed of member representatives from
the three signatory states, the federal government, environmental groups, and Basin water users. The Governance
Committee was charged with developing details of the first 13-year long increment of the PRRIP. Without the PRRIP,
each significant water project or activity with a federal nexus in the Platte River Basin would be required to address and
comply with federal Endangered Species Act (ESA) regulations individually, a process that could be costly and
inefficient and would severely impact the feasibility of any such projects. The Cooperative Agreement is intended to
provide an “efficient, effective, and equitable way to create improvements in the habitat” of the four Platte River target
species while allowing numerous existing and some proposed Platte River water projects and activities to continue and
to meet the requirements of the ESA.
The Governance Committee prepared and submitted a draft PRRIP to the DOI for review under NEPA and for use in
preparing a Draft Environmental Impact Statement (DEIS). When submitted, the components of the draft PRRIP were
at various stages of development and completion. Following NEPA review, the DOI will issue a Record of Decision.
Following issuance of the Record of Decision, the governors of Wyoming, Nebraska, and Colorado and the U.S.
Secretary of the Interior may enter into a PRRIP, which is anticipated to occur in 2006.
The U.S. Bureau of Reclamation (USBR) and the USFWS have jointly prepared a DEIS for the first 13-year increment
of the Governance Committee’s PRRIP. The DEIS assesses the environmental consequences of the PRRIP as required
by NEPA. USBR and USFWS released the DEIS for public comment in January 2004. The DEIS is the precursor to
an Environmental Impact Statement (EIS) that is required by NEPA.
P L A T T E R I V E R B A S I N P L A N W A T E R A T L A S E D U C A T I O N A L T O O L
An online educational tool called the Platte River Basin Water Atlas was also developed as part of this study. The
Water Atlas is intended to serve as an information resource accessible to the general public via the internet that broadly
educates the public about the water resources of Wyoming’s Platte River Basin. The Water Atlas is an ideal way to
begin exploring for information presented in the Basin Plan. Access to the Water Atlas is available through the Water
Plan website at http://waterplan.state.wy.us.
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E X E C U T I V E S U M M A R Y
A G R I C U L T U R A L W A T E R U S E
Almost half of Wyoming’s irrigated acres lie
within the Platte River Basin, and nearly half
of the state’s livestock are raised in the Basin.
Agricultural operations are the single largest
consumer of water in Wyoming’s Platte River
Basin.
F E D E R A L I R R I G A T I O N P R O J E C T S I N
W Y O M I N G ’ S P L A T T E R I V E R B A S I N
The federal government constructed many
dams, diversions, canals, and related facilities during the twentieth century on and near the North Platte River in
Wyoming. These structures include the largest reservoirs in Wyoming’s Platte River Basin and play a major role in
controlling and utilizing Basin surface water resources. These structures are located in the Above Pathfinder and
Pathfinder to Guernsey subbasins of Wyoming’s Platte River Basin. Dams and reservoirs were constructed as
components of large federal irrigation projects, including, in chronological order:
" The North Platte Project
! Created Pathfinder and Guernsey Reservoirs
! Developed 2,000 miles of irrigation canals, laterals, and drains
! Fully supplies irrigation water for 226,000 acres
" The Kendrick Project
! Major components are Seminoe Dam and Reservoir, Seminoe Powerplant, Alcova Dam and Reservoir, Alcova
Powerplant, and the Casper Canal
! Supplies irrigation water to 24,000 acres
" The Kortes Unit of the Pick-Sloan Missouri River Basin Project
! Includes Kortes Dam, Reservoir, and Powerplant
" The Glendo Unit of the Pick-Sloan Missouri River Basin Project
! Includes Glendo Dam and Reservoir, Glendo Powerplant, Gray Reef Dam and Reservoir, and Fremont Canyon
Power Plant
These federal facilities are administered by the U.S. Bureau of Reclamation (USBR) and are intended primarily to
provide storage of irrigation water and subsequent generation of electrical power as the irrigation water is released.
M U N I C I P A L A N D D O M E S T I C W A T E R U S E
The overall domestic and municipal water use in the Platte River Basin of Wyoming were estimated as part of the
Basin Plan. Estimates were prepared independently of Wyoming’s Depletions Plan (WDP) and followed a different
methodology than what is being considered for the proposed Platte River Recovery Implementation Program. Specific
criteria were established to identify municipal verses domestic use.
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P L A T T E R I V E R B A S I N P R O J E C T
According to the Environmental Protection Agency (EPA), there are currently 54 active municipal and community
public water systems within Wyoming’s Platte River Basin. A total of 195,107 people within the Platte River Basin are
served by these community systems. This population utilizes a combination of surface water and groundwater and
demands an average of 41.0 million gallons per day (mgd), or roughly 210 gallons per capita per day (gpcpd), and a
peak daily amount of 110.8 mgd. Based on WWDC (2002) data, it appears that the majority of the municipal and
community public water systems in the Platte River Basin have sufficient water to meet current and future needs.
Based on rural domestic and non-community public water system usage, the average total domestic water usage for the
Platte River Basin is estimated to range from 8.29 mgd to 15.36 mgd. Assuming a rural domestic population of 47,138
and an average demand of 150 to 300 gallons per capita per day (gpcpd), estimated rural domestic groundwater use
ranges from 7.07 mgd to 14.14 mgd. For the 16,270 people in the subbasin who use the 79 non-community public
water systems, estimated domestic water usage is 1.22 mgd based on assumed usage of 75 gpcpd.
I N D U S T R I A L W A T E R U S E
Basin industry has developed at a fairly slow pace except during boom periods. Industries that consumed the most
water in the Platte River Basin between 1981 and 2000 were the oil, coal, and uranium exploration and extraction
industries. Power generation facilities, aggregate and cement production plants, an ammonium-nitrate production
plant, a sugar beet processing facility, and an ethanol production plant have also been significant users of groundwater
and surface water supplies in the Platte River Basin. Total permitted industrial use of water in the Wyoming Platte
River Basin is comprised of approximately 75 percent groundwater and 25 percent surface water.
R E C R E A T I O N A L W A T E R U S E
Water has many uses in an arid state such as Wyoming, and one of the most important and valued to the culture of
Wyoming is recreational use. While water projects were originally developed to provide an adequate water supply for
irrigation projects, to control flooding, and to generate hydroelectric power, the use and importance of these waters for
recreation continue to grow. There are several types of recreation in the Platte River Basin that are directly contingent
upon a stable water resource. These include, but are not limited to, boating, fishing, waterfowl hunting, swimming,
camping, skiing, snowmobiling, and golfing. With the exception of irrigation on the Basin’s nineteen golf courses,
these recreational uses are generally non-consumptive in nature yet rely upon a consistent water source, whether it is a
running stream or a standing water body.
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E X E C U T I V E S U M M A R Y
E N V I R O N M E N T A L W A T E R U S E
Environmental water use within the Platte River Basin includes maintenance of minimum stream flow rates and
reservoir water levels to protect new and existing fisheries and wildlife habitat. Instream flow filings, instream
bypasses, and minimum reservoir releases are three tools used by state and federal agencies to produce and protect
fisheries habitat in the Platte River Basin that has been impacted by historical low flow conditions. Due to the nonconsumptive
nature of environmental water uses, water consumption attributed to environmental use is minimal and is
due primarily to evaporative loss.
W A T E R U S E F R O M S T O R A G E
Reservoirs in the Platte River Basin are owned and operated by a variety of entities, including the USBR,
municipalities, irrigation districts, and private individuals. Information regarding reservoirs with permitted capacities
greater than 50 acre-feet are compiled in the Plan.
The federal reservoirs on North Platte River in Wyoming are a key water supply component to federal irrigation
projects located downstream. Federal reservoirs, in order of occurrence on the North Platte River in Wyoming from
upstream to downstream, are:
" Seminoe Reservoir
" Kortes Reservoir
" Pathfinder Reservoir
" Alcova Reservoir
" Gray Reef Reservoir
" Glendo Reservoir
" Guernsey Reservoir
Total storage capacity of these federal reservoirs is in excess of 3 million acre-feet. Benefits from stored water in these
federal reservoirs include water supplies for irrigation and power generation, as well as recreation and flood control.
In addition to descriptions of the federal reservoirs, the Plan provides information on reservoirs that have capacities
over1,000 acre-feet, or that serve as a significant water supply within the River Basin.
C U R R E N T W A T E R U S E S U M M A R Y
As shown in the chart below, agriculture is obviously the most significant water use in the Basin. The industrial sector
also uses a comparitively large amount of water. This sector, which includes energy and minerals, has historically
added volatility to the Basin economy but has also provided high-paying jobs. While municipal water consumption is a
small percentage of the overall water used in the Basin, cities and towns have unique requirements that demand
reliability. Travel, tourism, and recreation contribute to the Basin economy, and water plays an important, but
somewhat different, role in this sector. Environmental water use is not quantified as it is typically non-consumptive
and relates to recreational use.
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P L A T T E R I V E R B A S I N P R O J E C T
The current water uses within the Basin are summarized as follows:
Recreational
1%
Municipal /
Domestic
3%
Industrial
13%
Agricultural
83%
A V A I L A B L E S U R F A C E W A T E R
A determination of the available water resources is a significant component to Wyoming’s river basin planning.
Available surface water has been estimated in other river basins by the development of simple computer models that
consider both hydrologic conditions and existing appropriations of the resource that constrain water availability.
Because the surface water resources of the Platte River Basin are widely acknowledged to be fully appropriated, the
scope for this component of the Platte River Basin Plan was modified, relative to the other river basin plans, to simply
characterize the resource. Accordingly, the surface water resources were determined by collection of stream gage data
and a study of the historic flow conditions across the Basin.
A V A I L A B L E G R O U N D W A T E R
In many ways, Wyoming’s Platte River Basin presents one of the most complicated groundwater regions in Wyoming
for a variety of political, geologic, and hydrogeologic reasons. While groundwater has always been an important water
source for municipal, agricultural, and other uses in the planning area, its importance and administrative complexity
have increased in recent years.
The North Platte River has been assessed as fully appropriated for some time, and several court decisions and interstate
agreements have recognized that hydrologically connected groundwater wells were impacting river flows. Both the
Modified North Platte Decree and Cooperative Agreement may affect the use and development of groundwater
resources within the Platte River Basin. An important criterion for assessing groundwater supplies is whether the
groundwater supply is hydrologically connected with tributary surface waters in the Basin.
The Plan inventories published information on the groundwater resources within the Basin and catalogs the State
Engineer’s groundwater permit database for the categories of existing groundwater uses. The information is presented
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E X E C U T I V E S U M M A R Y
in the form of project Geographic Information System (GIS) data layers for each subbasin, including:
" Permitted active municipal, domestic, industrial, agricultural, recreational, and environmental wells with permitted
production rates of 50 gallons per minute or greater
" Coal bed natural gas (methane) wells (where applicable)
The origins and status of the three basin groundwater control areas, including the Prairie Center Control Area, the
Laramie County Control Area, and the Platte County Control Area are also presented in the Plan. Other objectives of
this Plan included:
" Characterizing the aquifers of the planning area with regard to location, storage, and yield based on existing
information
" Summarizing the potential for additional groundwater development and aquifer storage, and any potential impacts
of such development to the groundwater and surface water systems in the Basin
" Characterizing coal bed natural gas (methane) development and its short- and long-term effects on groundwater
and surface water supplies within subbasins of the Platte River Basin
" Summarizing groundwater interference issues
Groundwater resouces are organized based on aquifer systems in the Basin, which are described by the geologic age of
the rock formations that form the aquifers. Groundwater quality in aquifers is variable and dependent upon a variety of
factors including, distance from the recharge area, aquifer transmissivity and storage, groundwater flow rates, aquifer
rock type, dissolution of soluble salts within the aquifer matrix, and leakage of poor quality water into the aquifer from
adjacent units. Generally, the best quality groundwater is present at locations closest to the geologic outcrop areas for
the aquifer systems.
D E M A N D P R O J E C T I O N S S U M M A R Y
Information was developed to establish a baseline for projecting long-term economic and demographic activity, and
projecting future water demand. Water demands, both in terms of diversions and consumptive use were developed
under three scenarios: High, Low, and Mid economic growth. The economic and demographic data were applied to
develop water demand projections for the three growth scenarios. In the simplest terms, the High Scenario incorporates
an estimation of the most growth in each of the key sectors and in the region that could potentially occur over the
forecast horizon. The Low Scenario embodies the estimated lowest simultaneous growth (or largest contraction)
reasonably likely to occur in each of the key sectors and in the region over the planning horizon. The Mid Scenario
represents the assumed most realistic level of growth likely to occur in each of the key sectors and in the region over
the planning horizon.
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P L A T T E R I V E R B A S I N P R O J E C T
The following table shows a summary of future water demands for each these growth scenarios categorized by use.
Summary of current and projected water uses (af/yr)
Current
Diversions
Projected Use by Growth Scenario (acre-feet/yr)
Diversions
Consumptive Use
Current
Consumptive
Use Low Mid High Low Mid High
Agricultural 1,559,300 668,300 1,527,200 1,559,600 1,647,600 655,200 667,600 707,600
Municipal/Domestic 49,100 24,500 71,000 75,600 89,000 35,400 37,800 44,600
Industrial 104,200 104,200 75,290 92,450 115,760 75,290 92,450 115,760
Recreational 8,440 4,410 8,440 9,740 12,240 4,410 5,010 6,310
Total 1,721,040 801,410 1,681,930 1,737,390 1,864,600 770,300 802,860 874,270
Surface water 1,528,000 677,000 1,511,100 1,546,900 1,661,400 669,400 684,400 748,200
Groundwater 193,040 124,410 170,830 190,490 203,200 100,900 118,460 126,070
Among the economic sectors, the largest projected changes in water demand occur in the municipal and rural domestic
sector, though total municipal water demand remains small relative to water demand in the agricultural sector. While
the agricultural sector experiences one of the smallest percentage changes over the projection period, the relative
magnitude of this sector’s water demand allows it to drive much of the projected annual and monthly water use
patterns. Although industrial water use declines except under the High Scenario, the sector’s diminutive size implies a
minimal overall impact on water demand in the Basin under any scenario. The recreational sector is also small and
exhibits only moderate changes in demand under the three scenarios. Demand in the environmental sector was defined
to include water used in enhancing environmental resources such as fish and wildlife habitat. Scenarios were defined
for this sector through assessment of the likelihood of future activity in the Basin; the approval or denial of instream
flow water rights largely drives future water demand in this sector by scenario.
P R O J E C T E D A N N U A L W A T E R D E M A N D S – H I G H S C E N E R I O
Under the assumption of a normal demand year, total Basin water diversion requirements are projected to increase by
about 8 percent from year 2005 to year 2035 under the High Scenario, an increase of 144,000 acre-feet. In a high
demand year, the increase is projected to be around 8 percent, or 202,000 acre-feet.
Under the High Scenario, total agricultural water demand grows moderately over the projection period. Agriculture
continues to comprise the vast majority of total water demand under the High Scenario; agriculture accounts for 88
percent of total water diverted and roughly 81 percent of total consumptive use in normal demand year 2035.
Consumptive use is only 43 percent of total diversions for irrigated agricultural production within the Basin, reflecting
low efficiencies and reuse of return flows. The vast majority of agricultural water demand remains in irrigated crop
production, with less than one percent of total projected agricultural diversions and consumptive use going to direct
livestock sustenance.
- 1 0 -

E X E C U T I V E S U M M A R Y
Under the High Scenario, municipal water demand in the Basin increases by 80 percent over the 30-year projection
period. Municipal water demand will remain a relatively small sector, accounting for only five percent of total water
diversions and five percent of total consumptive use in a normal demand year 2035.
Water demand within the industrial sector increases by about 11 percent over the projection period under the High
Scenario, both consumptive use and diversions. Industrial water demands are likely to continue to be a minor element
within the Basin, accounting for 13 percent of total consumptive use and six percent of total diversions under the High
Scenario in a normal year 2035.
Consumptively used water demand in the recreational sector increases under the High Scenario. While water use for
snowmaking will remain constant, water used for golf course irrigation is projected to increase by roughly 45 percent
over the projection period. Overall, recreational water consumption is expected to remain quite small, accounting for
less than one percent of Basin water demand.
The share of aggregate water demand met by groundwater resources versus surface water within the Basin remains
relatively constant over the projection period under the High Scenario. Almost 90 percent of water needs will continue
to come from surface water.
P R O J E C T E D A N N U A L W A T E R D E M A N D S – L O W S C E N A R I O
Total water diversion requirements under the Low Scenario in a normal demand year are projected to decline by two
percent from 2005 to 2035; high demand year diversion requirements are projected to drop by two percent over the
same period. Consumptive use is expected to drop slightly more under the Low Scenario, by four percent in a normal
demand year and by three percent in a high demand year.
Under the Low Scenario, total agricultural water demand declines slightly over the projection period – just two percent
when measured in terms of diversions or consumptive use. Agriculture continues to comprise the vast majority of total
water demand under the Low Scenario; agriculture is responsible for 91 percent of total water diverted and roughly 85
percent of total consumptive use in a normal demand year 2035. Consumptive use is only 43 percent of total diversions
for irrigated agricultural production within the Basin, reflecting low efficiencies and reuse of return flows. The vast
majority of agricultural water demand remains in irrigated crop production, with less than one percent of total projected
agricultural diversions and consumptive use going to direct livestock sustenance.
In the municipal sector, the 45 percent increase in both diversions and consumptive use is the direct result of the
projected increases in Basin population levels, but it remains a small portion of overall Basin water demands.
Under the Low Scenario, nearly one-third of industrial water demand wanes by 2035 as the oil production sector
declines and as mines close. This sector will represent an even smaller portion of overall water demands.
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P L A T T E R I V E R B A S I N P R O J E C T
Water demand in the recreational sector remains constant under the Low Scenario as no ski area expansions or golf
course developments are assumed to occur during the projection period. Overall, this sector is expected to remain
relatively small, accounting for less than one percent of water demand, both diversions and consumptive use.
Under the Low Scenario, the share of total groundwater diversions and consumptive use is expected to decrease
slightly, by roughly one to two percent. This change is due primarily to large losses in industrial groundwater use
expected under the Low Scenario.
P R O J E C T E D A N N U A L W A T E R D E M A N D S – M I D S C E N A R I O
Assuming a normal demand year, total Basin water diversions and consumptive use are projected to increase by about
one percent from year 2005 to year 2035 under the Mid Scenario. In a high demand year, diversions and consumptive
use are also expected to increase by around one percent over the planning horizon. The projected difference in
aggregate diversions and aggregate consumptive use under normal water demand conditions amounts to roughly 16,000
acre-feet and 1,500 acre-feet, respectively.
Under the Mid Scenario, total agricultural water demand declines very slightly over the projection period, measured in
terms of diversions or consumptive use. Agriculture continues to comprise the vast majority of total water demand
under the Mid Scenario; agriculture is responsible for 90 percent of total water diverted and roughly 83 percent of total
consumptive use in a normal demand year 2035. Consumptive use is only 43 percent of total diversions for irrigated
agricultural production within the Basin, reflecting low efficiencies and reuse of return flows. The vast majority of
agricultural water demand remains in irrigated crop production, with less than one percent of total projected
agricultural diversions and consumptive use going to direct livestock sustenance.
Under the Mid Scenario, while municipal water demand increases by 54 percent over the 30-year projection period, it
remains a relatively small sector, accounting for only four percent of total water diversions and five percent of total
consumptive use within the Basin in a normal demand year 2035.
Under the Mid Scenario, both water diversions and consumptive use in the Basin industrial sector are projected to
decline 11 percent from current levels. Industrial water use will become an even smaller portion of overall Basin water
demand, dropping to just five percent of diversions and 12 percent of consumptive use in a normal demand year 2035.
Water demand in the recreational sector grows moderately under the Mid Scenario as two new golf courses begin
operation in 2005; snowmaking water demands remain constant. Despite this increase in recreation diversions and
consumptive use of 15 percent, this sector remains quite small overall, accounting for less one percent of Basin water
demand, both diversions and consumptive use.
Under the Mid Scenario, the share of total diversions and consumptive use from groundwater sources is projected to
decrease slightly as large industrial groundwater uses wane over the projection period.
- 1 2 -

E X E C U T I V E S U M M A R Y
F U T U R E W A T E R U S E O P P O R T U N I T I E S
Future development and use of water in Wyoming’s Platte River Basin may be limited or otherwise impacted by a
variety of factors, including water availability, funding, public involvement, court decrees, Platte River Recovery
Implementation Program (PRRIP), water quality, and regulatory issues.
The future water use opportunities that were evaluated are categorized as being either structural or non-structural.
Structural future water use opportunities are those that include, but are not limited to, new storage reservoirs,
conveyance system upgrades, water distribution enhancements, groundwater development, aquifer storage and recovery
projects, in-basin water transfer components, and transbasin diversions. Non-structural future water use opportunities
are those that include, but are not limited to, local and Basin-wide conservation and management, modified reservoir
operations, municipal water conservation, improved agricultural water use efficiencies, water right transfers and
exchanges, water banking, and conjunctive use options.
Potential future Platte River Basin water use opportunities may be assessed on the basis of a variety of considerations.
The following factors were considered during BAG discussions regarding further water use opportunities:
" Pertinent water use sectors
" Water availability
" Technical factors
" Economic factors
" Environmental factors
" Legal and institutional factors
" Public acceptance
" Water quality
" Ability to satisfy multiple demands
Following receipt of comments from the WWDC and stakeholders, the final list of future Platte River Basin water use
opportunities, was organized on the basis of structural and non-structural water use opportunities.
Structural future water use opportunities include:
" Groundwater augmentation – non-hydrologically connected to North Platte River surface water
" Upper Laramie River storage opportunities
" Transbasin diversions
" Snow fence
" Stormwater capture, storage, treatment, and management; irrigation with treated municipal wastewater; grey water
irrigation; and municipal irrigation using untreated water
" Modification of Pathfinder Dam and Reservoir
" Coal bed natural gas (methane)
" Regionalization of public water supply systems
- 1 3 -

P L A T T E R I V E R B A S I N P R O J E C T
" Co-production of electricity and hydrogen from existing hydropower facilities
" Improving agricultural irrigation system efficiencies
Non-structural future water use opportunities include:
" Drought response planning
" Weather modification
" Water conservation
" Water right transfers
" Enhancing recreational use of water resources
" Increasing runoff from national forests based on modified U.S. Forest Service policies and practices
" Water exchange/banking
" Multi-purpose flood control programs
" Utilization of WWDC’s small water project program
F U T U R E W A T E R P L A N D I R E C T I V E S
The Plan and Water Atlas are intended to be used as references for Wyoming citizens and State agencies to understand
the present uses of water and potential for future development of the resources within the Basin. It will be important to
update the Plan over time in order to maintain a current base of information on the water resources in Platte River
Basin.
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Page 1 of 4
Issues identified in the Platte River Basin
Category Issues Activities/Projects
Regulatory issues (was previously
Federal Involvement; Downstream
Claims; Water Rights)
Impacts on the Upper Platte due to Pathfinder/Inland Lakes issues
Endangered Species Act (ESA) issues
Additional costs associated with federal involvement
Additional restrictions on use related to federal programs
Wyoming water first used in Wyoming
Change of use from irrigation to ESA/municipal use
Sale of water rights to other users or entities (consequences of law)
Water quantity to satisfy all users
Leasing or sale of water rights (law)
Potential challenges to prior appropriation doctrine
Property rights
Effects of modified North Platte Decree
Effects of Pathfinder modifications
Irrigation return flow considerations
Water Development Inter-basin water transfers for agricultural, municipal, domestic use Weather Modification
Forest management for forest yield
Management of water resources (are we doing everything we can?)
Poor geography for dam sites
Funding projects - rural vs. urban
Industrial growth (lack of water resources)
Economic opportunities of water storage projects, jobs, hydroelectric power, construction,
maintenance, etc
Modified North Platte Decree availability of water
Water quality
Endangered Species Act (ESA) issues
Importance of irrigation to maximize agricultural production
Irrigation return flow considerations
Industrial/Manufacturing/Minerals Extraction - adequate rights (priority and quantity) for future
industrial expansion, new venture opportunities; conservation incentives
State Regulatory
Conversion of agricultural lands to other uses
Modified North Platte River decree effects on water rights
1904 call effect on acreage that can be irrigated
Irrigation return flow considerations

Page 2 of 4
Issues identified in the Platte River Basin
Category Issues Activities/Projects
State Regulatory (cont.)
Regulations regarding water quality
Disaster and Emergency Response Contingency - should emergency uses (i.e. fighting forest
fires) take priority over ESA, prioirty decree, etc.?
Industrial/Manufacturing/Minerals Extraction - adequate rights (priority and quantity) for future
industrial expansion, new venture opportunities; conservation incentives
Ability to store direct-flow rights later/longer irrigation by more conservative irrigation practices
Contamination through industrial, agriculture or municipal discharge
State regulations on water quality
Natural impairment - stream classification based on water quality
Federal Regulatory
Consumptive Use
Irrigation return flow considerations
Regulations regarding water quality
Disaster and Emergency Response Contingency - should emergency uses (i.e. fighting forest
fires) take priority over ESA, prioirty decree, etc.?
Recreation - low priority; effects of prolonged droughtwater availability for recreational
purposes; federal facilities impact water designated for other uses
Achieve full storage capacity as per North Platte Decree
Clean Water Act (CWA) renewal impacts
Contamination through industrial, agriculture or municipal discharge
Federal regulations on water quality
Natural impairment - stream classification based on water quality
Importance of irrigation to maximize agricultural production
Irrigation return flow considerations
Prior appropriation doctrine property issues
Effects of prolonged drought
Irrigation distribution systems inefficiency
Enhanced education regarding natural flow
Continue silt run by dredging or other means
Geological constraints
Surface/groundwater interactions
Aquifer contamination
Water quality
Saratoga, Riverside/Encampment, Cheyenne GW Exploration
(Belvoir), Splitrock, Douglas, Glenrock, Pine Bluffs, Albin

Page 3 of 4
Issues identified in the Platte River Basin
Category Issues Activities/Projects
Consumptive Use (cont.)
Non-consumptive use
Aquifer depletions, over-appropriation
Effects of prolonged drought
Industrial/Manufacturing/Minerals Extraction - adequate rights (priority and quantity) for future
industrial expansion, new venture opportunities; conservation incentives
Municipal/Domestic
Lack of planning (rural subdivisions)
Water quality regulations
Surface water/groundwater
Restrictions on use
Water storage regulations
Growth
Return flow
Metered systems
Regionalization
Conservation water rates
Prolonged droughtwater availability
Limit landscape water use for new construction
Water conservation and reuse - cause and effect
Irrigation return flow considerations
Recreation - low priority; effects of prolonged droughtwater availability for recreational
purposes; federal facilities impact water designated for other uses
In-bank storage to enhance stream flow
Use Wyoming water in Wyoming
Change laws to allow alternate instream uses
Wyoming Game & Fish Dept. instream filings use of Public Trust Doctrine
Water origin when demand exceeds supply
Effects of prolonged drought - which water use is affected first?
Water conservation and reuse - cause and effect
Laramie, Casper Master Plan, Rawlins raw water storage

Page 4 of 4
Priorities for Platte River Basin
Need for increasing water supplies in the
Platte River Basin--use Wyoming's water in
Wyoming; Transbasin diversions; water
conservation; maximize water quantity;
groundwater resources
Increasing storage capacity in the basin
Regulatory climate conducive to increasing
storage and water utilization in the Platte
Basin
Planning for economic and population growth
water needs
Where's water going to come from for future growth (municipal, industrial)
question raised about transfer of direct flow rights to storage
Endangered Species demands for water (ESA)
Front Range growth encrouching to Wyoming
Assuring that water quality is adequate for
uses anticipated for the basin in the future

POWDER/TONGUE RIVER BASIN

Powder/Tongue River Basin Plan
Executive Summary
Prepared for:
Wyoming Water Development Commission
Basin Planning Program
Prepared by:
HKM Engineering Inc.
Lord Consulting
Watts and Associates
February 2002

Powder/Tongue River Basin Plan
Executive Summary
Prepared for:
Wyoming Water Development Commission
Basin Planning Program
Prepared by:
HKM Engineering Inc.
Lord Consulting
Watts and Associates
February 2002

Executive Summary
Powder/Tongue River Basin Plan
Project Scope
The Powder/Tongue River Basin Plan document is one of four River Basin Plans thus far
completed by the Wyoming Water Development Commission as authorized by the Wyoming
Legislature in 1999. The plans for the Bear River Basin and Green River Basin were completed
in 2001, and the plan for the Northeast Wyoming River Basins is being completed concurrently
with the Powder/Tongue River Basin Plan. The Wind/Big Horn River Basin and the Snake/Salt
River Basin plans were initiated in 2002 and the plan for the North Platte River will commence
in the near future. It is the express desire of the program to revisit and update the basin planning
documents every five years.
This planning document presents current and projected future uses of water in Wyoming’s
Powder/Tongue River Basin. Uses inventoried and analyzed in this plan include agricultural,
municipal, industrial, environmental, and recreational. Surface and ground water uses are both
described as is overall water quality. Given current uses, the availability of surface water and
ground water to meet estimated future requirements is analyzed. The current institutional and
legal framework of water development and management is presented.
The primary products of this planning study are technical memoranda prepared for the large
number of topics addressed in the plan. These memoranda provide detailed descriptions of the
data collected, source references, analyses performed, tools developed, and the results of each
investigation required to fully explore the water resources within the planning area. The intent of
this Executive Summary, and the associated Final Report, is to describe the planning study in
sufficient detail for the reader to gain a general understanding of the investigations that were
performed and the results of those investigations. For detailed information on a specific topic the
reader is directed to the technical memorandum prepared for that topic.
Basin Description
The study area of the Powder/Tongue River Basin Plan includes the drainages of the Little
Bighorn River, Tongue River, Powder River, and Little Powder River. These river basins
encompass all or part of Sheridan, Johnson, Campbell, Natrona, and Converse counties as well as
a small part of Washakie county in north central Wyoming. The planning area is shown on
Figure 1.
Climate throughout the Basin varies, but generally follows the pattern of a high desert region.
Annual precipitation in the range of 13 to 15 inches is the norm for the majority of the planning
area.
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Powder/Tongue River Basin Plan – Executive Summary
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Powder/Tongue River Basin Plan – Executive Summary
The major rivers and streams in the study area include the following:
! Little Bighorn River Basin – Little Bighorn River, Elkhorn Creek, Red Canyon Creek,
and East Pass Creek
! Tongue River Basin – Goose Creek, Big Goose Creek, Little Goose Creek, Prairie Dog
Creek, and Tongue River.
! Powder River Basin – Powder River, Little Powder River, Clear Creek, Piney Creek, and
Crazy Woman Creek
There have been a number of reservoirs developed in the Powder/Tongue River Basin to enhance
the water supply in the study area. The major storage facilities include:
! Tongue River Basin – Twin Lakes, Big Goose Park Reservoir, Cross Creek Reservoir,
Big Horn Reservoir, Dome Lake, and Sawmill Reservoir
! Powder River Basin – Lake DeSmet, Healy Reservoir, Kearney Lake, Willow Park
Reservoir, Cloud Peak Reservoir, and Tie Hack Reservoir, in the Clear Creek watershed,
Muddy Guard No. 2 Reservoir in the Crazy Woman Creek drainage, and Dull Knife
Reservoir on the North Fork of the Powder River.
Water Law and the Yellowstone River Compact
The Wyoming constitution establishes water in the state to be the property of the state.
Consequently, all development and management of water resources in Wyoming is governed by
the water laws embodied in the Constitution and Statutes. These water laws are recognized as
inviolate in the river basin planning program.
The Yellowstone River Compact of 1950 controls the development and use of water from the
Tongue River, Powder River, and Little Powder River. This compact divides the unappropriated
flow of the Tongue River, Powder River, and Little Powder River, after needs for supplemental
supply for existing rights are met, as follows:
! Tongue River: 40% to Wyoming, 60% to Montana
! Powder River and Little Powder River: 42% to Wyoming, 58% to Montana
Article X of the Compact stipulates that no water shall be diverted from the Yellowstone River
Basin without the unanimous consent of the three signatory states, Wyoming, Montana, and
North Dakota.
Agricultural Water Use
Irrigated agriculture in the planning area is primarily associated with forage production for the
livestock industry. Ranchers depend on irrigated cropland to provide winter feed and summer
grazing for their stock. Alfalfa, grass hay, and pasture grass are the dominant crops grown in the
planning area. Lesser amounts of small grains and corn are also produced. In total, 161,360
acres of land are actively irrigated in the planning area and the vast majority of these lands are
irrigated with surface water.
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Powder/Tongue River Basin Plan – Executive Summary
The depletion of water by irrigation is primarily dependent on the number of acres irrigated, the
crop water demands, and the amount of water available to meet these demands. Depletions for
wet, normal, and dry years total 194,000 acre-feet, 184,000 acre-feet, and 178,000 acre-feet
respectively.
Municipal and Domestic Water Use
There are twenty public water supply entities in the planning area, consisting of incorporated
municipalities, districts, and privately owned water systems. Two of the communities obtain
water from sources outside the study area. Four of the entities obtain their primary water supply
from surface water and consume approximately 2,700 acre-feet per year. The remaining sixteen
entities use approximately 500 acre-feet per year of ground water. Domestic use is satisfied by
ground water and is on the order of 2,400 to 4,400 acre-feet per year.
Industrial Water Use
Conventional oil and gas production and coalbed methane development constitute the industrial
water use in the Powder/Tongue River Basin. The estimated depletion of ground water for these
uses is approximately 68,000 acre-feet per year. No water is currently being used in the study
area for electric power generation or coal mining. Lake DeSmet has been developed as a surface
water supply for future electric power generation, but this source has yet to be utilized.
Recreational Water Use
Recreational uses associated with the water resources of the Powder/Tongue River Basin include
boating, fishing, and waterfowl hunting. Although these uses are generally non-consumptive,
water-based recreation is enhanced through minimum flow releases from reservoirs, minimum
pool levels maintained in reservoirs, and instream flow water rights established on streams. Lake
DeSmet, the largest standing water recreation attraction in the Powder/Tongue River Basin,
supports skiing, fishing, swimming, boating, and camping.
Environmental Water Use
Environmental uses of water in the Powder/Tongue River Basin are largely non-consumptive.
Environmental use topics addressed in this planning study include water administration
(minimum flow releases, minimum pool maintenance, and instream flow water rights),
environmental concerns associated with water produced by coal bed methane development, and
wetland mapping. Concerns expressed by environmental organizations are also presented in the
basin plan.
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Powder/Tongue River Basin Plan – Executive Summary
Reservoir Evaporation
The majority of water use from storage reservoirs within the Powder/Tongue River Basin is for
irrigation. Evaporation from these storage reservoirs constitutes another consumptive use of
water within the planning area. Evaporation from the 14 key storage facilities (generally larger
than 1,000 acre-feet) totals 11,300 acre-feet annually.
Current Water Use Summary
The current water uses in the planning area are summarized as follows:
Water Use
Surface
Water
Dry Year Normal Year Wet Year
(AF/Year)
Ground Surface Ground Surface
Water Water Water Water
Ground
Water
Agricultural 178,000 200 184,000 200 194,000 300
Municipal 2,700 500 2,700 500 2,700 500
Domestic --- 4,400 --- 4,400 --- 4,400
Industrial 1 --- 68,000 --- 68,000 --- 68,000
Recreation
Non-consumptive
Environmental
Non-consumptive
Evaporation 11,300 11,300 11,300
TOTAL 192,000 73,100 198,000 73,100 208,000 73,200
Note 1: Includes conventional oil and gas production water and CBM production water.
Available Surface Water
The determination of available surface water was broken down into the following seven tasks for
this study:
8. Compilation of Historic Streamflow Records
9. Selection of an appropriate Study Period
10. Extension of Records to represent the entire study period
11. Estimating Natural Flow at Ungaged Model Nodes
12. Determining Streamflows during Wet, Normal, and Dry years
13. Development and Calibration of Spreadsheet Models
14. Determination of Available Surface Water
Records from 114 USGS and SEO streamflow gages were compiled and then extended where
records were missing, to provide estimates of streamflow for each month, of each year during the
1970 to 1999 study period. These recorded and estimated streamflows were used together with
regression equations developed by the USGS to determine the amount of streamflow at
additional ungaged locations needed for the water availability models. The annual streamflows
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Powder/Tongue River Basin Plan – Executive Summary
were ranked and the years were divided into three hydrologic conditions (dry years, normal
years, and wet years). The average flows for each of these three conditions are primary inputs to
the models.
Water availability spreadsheet models were developed for the following six sub-basins within the
Powder/Tongue River Basin planning area:
! Little Bighorn River sub-basin
! Tongue River sub-basin
! Clear Creek sub-basin
! Crazy Woman Creek sub-basin
! Powder River sub-basin
! Little Powder River sub-basin
Three models were developed for each sub-basin to represent each of the three hydrologic
conditions. The models each represent one calendar year of flows, on a monthly time step.
Streamflow, estimated actual diversions, full supply diversions, irrigation returns, and reservoir
storage conditions are the basic input data to the models. For all of these data, average values
drawn from the dry, normal, or wet years of the study period were computed for use in the
spreadsheets.
The models do not explicitly account for water rights nor are the models operated based on these
legal constraints. Further, the models do not associate supplemental reservoir releases to the
specific water users. However, by calibrating the models to historical streamflows at gaged
locations, the models can be used to generally represent existing operations. Model inputs can
then be modified to estimate the impacts associated with potential future water projects.
The total annual flow, physically available in excess of current Wyoming water demands, is
summarized as follows:
Hydrologic Condition
Subbasin Wet Years Normal Years Dry Years
Little Bighorn River 152,000 113,000 81,000
Tongue River 473,000 326,000 218,000
Clear Creek 213,000 124,000 80,000
Crazy Woman Creek 69,000 32,000 16,000
Powder River 547,000 324,000 194,000
Little Powder River 48,000 12,000 3,000
The Yellowstone River Compact of 1950 governs the allocation of the waters in the Powder
River and Tongue River between the States of Montana and Wyoming.
The methodology used in the current study to evaluate water availability under the Yellowstone
River Compact was coordinated through the Wyoming State Engineer’s Office and relies heavily
on previous work performed by each of the two States. Wyoming’s estimated compact
allocation under each of the three hydrologic conditions is summarized as follows.
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Powder/Tongue River Basin Plan – Executive Summary
Tongue River Basin
Hydrologic Condition
Conservative Liberal Estimate Powder River
Estimate
Basin
Wet Years 163,000 189,000 211,500
Normal Years 90,000 117,000 131,100
Dry Years 40,000 67,000 74,300
Available Ground Water
The objectives of this element of the study were as follows:
1. Inventory and catalog the Wyoming State Engineer's Office (SEO) ground water permit
database for various categories of ground water uses in the planning area, and incorporate the
information into GIS data themes.
2. Inventory and document existing published data on ground water studies and ground water
planning documents for the planning area.
3. Summarize existing information on aquifers with regards to location, storage, yield and
development potential within the planning area.
4. Summarize the potential effects that ground water development might have on the ground
water and surface water systems in the basins within the planning area.
5. Characterize coalbed methane development and its short and long-term effects on ground
water and surface water supplies within the river basins of the planning area.
The information developed through this study provides a starting point for site specific ground
water investigations.
The significance of ground water in the planning area is demonstrated by the 16,432 active
ground water permits (as of December 31, 2000) within the planning area. Because of the
dynamic nature of coalbed methane (CBM) development, the inventory of permitted CBM wells
was updated to reflect data as of December 31, 2001. The number of permits for each use
category are summarized below:
! 111 Permitted active agricultural wells with production rates greater than 49 gpm
! 8 Permitted active municipal wells with production rates greater than 49 gpm
! 301 Permitted active industrial and miscellaneous wells with production rates greater
than 49 gpm
! 4,646 Active permitted domestic wells
! 4,546 Active permitted stock wells
! 6,820 Permitted coalbed methane wells (9393 by December 31,2001)
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Powder/Tongue River Basin Plan – Executive Summary
The five major aquifer systems within the planning area are (oldest to youngest): 1) Madison
Aquifer System; 2) Dakota Aquifer System; 3) Fox Hills/Lance Aquifer System; 4) Fort
Union/Wasatch Aquifer System; and 5) Quaternary Alluvial Aquifer System.
General conclusions regarding ground water development potential of four of these five major
aquifer systems are summarized below:
! The Madison Aquifer System may have the most development potential for high yield
wells on a sustained basis. Drilling depths and water quality may constrain development
at specific locations within the planning area.
! The Fox Hills/Lance Aquifer System may have local potential for development of wells
with low to moderate yields. The possible high fluoride content in water from this
system might influence the desirability of use for a municipal/public supply without
provision for treatment or special management.
! The Fort Union/Wasatch Aquifer System is utilized for most uses in the planning area.
The Wyodak-Anderson coal and hydraulically interconnected aquifers of the Aquifer
System will be heavily impacted by ground water withdrawals in and near coalbed
methane development. The water co-produced with coalbed methane may provide an
opportunity for utilization, depending on location, quality and nature of potential use.
! Aquifers in the Quaternary Alluvial Aquifer System may have local development
potential if induced infiltration of surface water can be tolerated.
Out of a total of 16,432 active ground water permits inventoried as of December 31, 2000, 9,612
of the permits were for WWDC categories other than coalbed methane development
(agricultural, municipal, industrial, domestic and stock). Possible impacts of further development
for these uses could include:
! Depletion of surface water that is interconnected with aquifer systems. The principal
aquifer systems of concern with respect to this impact include the Madison and the
Quaternary Alluvial Aquifer Systems.
! Interference problems between wells and / or aquifer depletion problems related to
domestic and stock well densities.
! Aquifer depletion where aquifers are used for secondary oil and gas recovery operations.
! Water quality impacts due to oil and gas drilling and recovery operations and leakage
through inadequate or failed plugging of production wells.
A total of 9,393 permitted coalbed methane wells (December 31, 2001) were identified. Possible
impacts of coalbed methane development include:
! The dewatering of aquifers and the lowering of water levels and yields in production
wells located in the vicinity of coalbed methane development.
! Methane seepage into wells and structures in the proximity of coalbed methane
development that could pose a health and safety hazard to residents.
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Powder/Tongue River Basin Plan – Executive Summary
! Increased infiltration of water from coalbed methane production into shallow alluvial
ground water systems that could aggravate subsurface structure problems.
! Increased infiltration of water from coalbed methane production into shallow ground
water systems that could impact the quality and use of ground water from shallow
systems.
! Impacts to surface coal mining operations.
Possible surface water related impacts that have been identified could include:
! Change in drainage characteristics from ephemeral to perennial. This could result in an
increase in the erosion potential and sedimentation problems in receiving drainages.
! Increased flooding potential in receiving drainages. Higher flows could also impede
landowner access associated with their operations.
! Alteration of the chemical characteristics of receiving surface waters due to coalbed
methane generated water. This could include a change due to increased salinity and
sodium content that could impact irrigation practices and the utilization of surface water
for irrigation.
Irrigation Use Projections
To assess future water needs in the Powder/Tongue River Basin, projections of water demands
were developed for major water use categories through the year 2030. Surface water uses were
projected for low, moderate, and high growth scenarios.
Future demands for irrigation water are largely dependent upon factors such as crop and
livestock prices and the cost of developing new water storage and delivery systems. The low
growth scenario projects no changes in those factors relative to current conditions, and thus no
increase in irrigation water use. The moderate and high growth scenarios project moderate
increases in irrigation water use based upon projected increases in crop and livestock prices and
the possibility of increased state assistance in developing new irrigation water supplies. For the
moderate growth scenario, consumptive irrigation water use rises from a current level of 184,000
acre-feet annually to 194,000 acre-feet annually by the year 2030, an increase of six percent. For
the high growth scenario, consumptive use rises to 205,000 acre-feet annually by 2030.
Municipal and Domestic Use Projections
The larger municipalities in the Powder/Tongue River Basin rely upon surface water sources to
meet their needs. Their future municipal water demands are closely tied to future population
levels in the planning area. Three population-forecasting methods were used to develop low,
moderate, and high growth population projections for communities in the Powder/Tongue River
Basin through the year 2030. Based upon these projections, municipal surface water use is
expected to grow from a current level of 2,700 acre-feet annually to 3,200 acre-feet annually by
2030 for the low growth scenario. For the moderate and high growth scenarios, the increases are
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Powder/Tongue River Basin Plan – Executive Summary
to 3,500 and 3,800 acre-feet respectively. Domestic water needs in the Powder/Tongue River
Basin are typically satisfied by groundwater. Projections developed for this plan Indicate that
domestic water use is expected to increase from a current level of about 4,800 acre-feet annually
to between 5,500 and 6,400 acre-feet by the year 2030.
Industrial Use Projections
There are no large industrial users of surface water in the planning area. Industries such as oil
and gas development and mining all make use of relatively small amounts of groundwater. That
situation could change in the future with the construction of coal-fired electric generating
facilities and coal-conversion facilities designed to increase the heat content of coal. For the low
growth scenario, no such developments are projected to take place. For the moderate and high
growth scenarios, however, industrial surface water demand is expected to grow to between
17,000 and 35,000 acre-feet annually by 2030.
Recreation Use Projections
Fishing is the predominant water-based recreational activity in the planning area, and angers
currently engage in approximately 272,000 activity days of fishing each year. Projections
developed for this plan indicate fishing demand is expected to increase to between about 330,000
and 430,000 activity days annually by the year 2030. The Powder/Tongue River Basin is well
endowed with both stream and stillwater fisheries, which are generally adequate to meet current
demands. These resources will come under increasing pressure as recreational demand increases
as a result of population growth and increases in tourism.
Environmental Use Projections
Environmental water requirements are not directly related to changes in population or tourism,
but instead reflect human desires concerning the type of environment in which people want to
live. These desires are reflected in environmental programs and regulations promulgated by
elected representatives at the local, state and federal levels. Examples include Wyoming’s
instream flow statues and minimum reservoir pools dedicated to fish and wildlife enhancement.
While generally non-consumptive, environmental needs can conflict with consumptive water
uses in some situations. No significant conflicts between environmental and consumptive water
uses are projected for the Powder/Tongue River Basin.
Compact Considerations
Wyoming’s use of surface waters from the Powder and Tongue Rivers is subject to limitation by
interstate compact. Projected surface water demands were contrasted with estimates of
Wyoming’s remaining allocations of water in the Powder and Tongue River sub-basins. No
potential conflicts were identified.
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Powder/Tongue River Basin Plan – Executive Summary
Demand Projections Summary
The projected surface water uses are summarized in the following table for the low, moderate,
and high growth scenarios.
Summary of Current and Projected Surface Water Uses
Projected Use by Growth Scenario
(Acre-feet/Yr.)
Use Current Low Moderate High
Municipal 2,700 3,200 3,500 3,800
Industrial (included in municipal) (included in municipal) 17,000 35,000
Irrigation 184,000 184,000 194,000 205,000
Evaporation 11,300 11,300 11,300 11,300
Recreational
Environmental
(non-consumptive)
(not estimated)
Total 198,000 198,500 225,800 255,100
Future Water Use Opportunities
This river basin plan quantifies water resources available for development and use and identifies
current and projected future water needs in the Powder/Tongue River Basin. The concluding
task of this study is to identify future water use opportunities that can be implemented to satisfy
the water demands in the Little Big Horn River, Tongue River, and Powder River Basins in
Wyoming. The list of potential water use opportunities provided is intended to assist individuals
and organizations in finding ways to meet their specific needs.
To further assist the users of this list in identifying potential opportunities to satisfy their
demands, a methodology is presented that can be employed to evaluate a specific opportunity on
the list relative to similar and related opportunities. The suggested methodology evaluates
opportunities according to the likelihood they are desirable, functional, and capable of receiving
the support required for development. By using the list of future water use opportunities and
employing the evaluation methodology, individuals and organizations will have “a place to start”
in their investigation.
The procedure used to complete this task consisted of four steps:
5. Develop screening criteria to evaluate future water use opportunities – the six screening
criteria are: 1) water availability; 2) financial feasibility; 3) number of sponsors,
beneficiaries, and participants; 4) public acceptance; 5) legal and institutional concerns; and,
6) environmental and recreational benefits.
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Powder/Tongue River Basin Plan – Executive Summary
6. Develop a long-list of future water use opportunities – this list was compiled from published
reports and information provided by the members of the Basin Advisory Group (BAG).
7. Develop a short-list of opportunities – projects and opportunities on the long-list were
screened to eliminate projects considered to have little likelihood of development.
8. Evaluate the opportunities on the short-list – the projects advancing to the short-list were
categorized by location and type, then evaluated using the criteria developed in Step 1 of the
process.
Legal and institutional constraints that need to be addressed in water management and
development were identified and described in the planning study.
The success of a water development project is also dependent on the ability of the source to meet
the water quality needs of the proposed uses. In addition, the project itself must protect existing
and potential uses of waters of the State. As a part of this river basin planning process a
description of the water quality character of the Powder/Tongue River Basin was developed.
The plan also describes contemporary water quality programs initiated to protect and enhance the
quality of surface water in the planning area. Finally, the primary issues related to the quality of
water in the planning area are detailed in industrial, agricultural, and municipal categories.
12 of 12

1 of 5
Issues identified in the Powder/Tongue River Basin
Category Issues Activities/Projects
Water Quality - Stream classification (DEQ & G&F)
- Baseline data collection - groundwater and surface water
- TMDL
- NPDES permitting
- Erosion sediment disposition
- CBM discharge
- Aquifer commingling
- Agricultural feeding operations and confined agricultural
feeding operations (AFO/CAFO)
- Land use impacts
- Aquifer classification
- Storm water discharge
- Best management practices (BMPs)
- Irrigation return flows
- Water temperature
- Transbasin diversions
- Herbicide/pesticide use and runoff (golf course)
- Well classification
- Irrigation practices
- Sodium adsorption ratio (SAR)
- Leach fields impact/subsurface discharges
Water Rights - Preservation of existing rights prior to compacts
- Compact issues
- Transbasin and tributary diversions
- Change of use/change of point of diversion issues
- Federal takeover threats
- Instream flows - fisheries, esthetics, recreation
- Minimum pools in reservoirs for recreation/fish
- State water law
- Prior appropriation doctrine
- Permitting process
- Permitted uses Additional reservoir inspectors (SEO)
- Ditch right vs. water right
- Cumulative impacts from CBM water discharge
- Water reserves for future uses
- Low flows impacting fish and aquatic environment
- Unused water rights
- Abandoned water rights

2 of 5
Issues identified in the Powder/Tongue River Basin
Category Issues Activities/Projects
Future Use Projections - Recreation/tourism
- Aesthetic/Visual use
- Changing land use
- Energy use
- Technology
- Industry
- Economics
- Agriculture
- Pressure on infrastructure
Regulatory - Wetlands
- Instream flow requirements
- Source water protection
- Wellhead protection
- Emotional paranoia
- EPA trying to take over State's primacy
- Issues for new dam permitting
- Clean Water Act
- Endangered Species Act
- National Environmental Policy Act (NEPA)
- Permitted vs. non-permitted flow diversion
- EPA, DEQ, state, county, federal, other
- State and federal laws effecting use and development
- Safety of dams
- Corps, Game and Fish, US Fish and Wildlife, BIA - tribes
Public Education - Walls of Water
- Value and economic cost of water
- Conservation
- Help for ditch organizations
- Water law
- Understanding Clean Water Action plan
- Meeting
- College
- Schools
- COE (Corps of Engineers) permitting
- Economic benefits of CBM
- Radio/TV
- Coal seam depressurization

3 of 5
Issues identified in the Powder/Tongue River Basin
Category Issues Activities/Projects
Public Education (cont.) - Regulatory agency statute development
- Public regulatory contribution
- Fact vs. fiction
- NEPA process public input
- Funding
- Aquifer storage and retrieval (ASR) programs
Water Development - Rehab of existing conveyance systems (old ditches) Middle Fork Watershed Study
highest and best use priorities
- Municipal SAWS JPB, Lake DeSmet, Dayton, Ranchester,
Prairie Dog Watershed Study, Three Horses Watershed Study
- Agriculture
- Pipeline distribution stock water systems
- extreme difficulty in getting dams permitted
- Improved irrigation efficiency
- Minimum flows and flushing flows
below dams (present ones and future development)
- Fish loss to diversion ditches
- Plan, plan, plan
- Privatized public use systems
- Pre-compact projects
- New technologies and new uses
- Funding
Related Land Issues - Noxious weeds
- Streamback erosion
- Best management practices in riparian areas
- Wellhead protection
- Watershed management for water yield
- Land ownership patterns
- Restoration/reclamation/rehabilitation
- Recreational overgrazing
Water Quantity - Recharge area protection
- Baseline data collection - groundwater and surface water
- Water quantity and occurrence
- Interbasin transfers and flows
- Recharge areas defined recharges
- Reinjection programs

4 of 5
Issues identified in the Powder/Tongue River Basin
Category Issues Activities/Projects
Water Quantity (cont.) - Reinjection to aquifers
- Planning for water quantity decreases following peak
development (resting the resource)
- Reservoir projects
- Conveyance losses
- Contract reservoir rights, how they fit, what is
their future, how dependable
- Fish need water too
- Precipitation Drought of Record (early 2000)
- Drip irrigation
- Conservation pools and flows
- Promoting opportunity for innovation, non-invasive
water management
- Preservation of watersheds
Conservation - Groundwater
- Surface water
- CBM water management
- Improved management practices
- Re-use
- Wild and scenic designations
- Improved irrigation practices
- Non-subsidized use (pay for what you use)
- Permaculture practices
- Protecting scenic watersheds, private cooperative
projects as opposed to government
- Managing (conserving) consumptive use
- Rehabilitation projects (irrigation)
- Preservation of watersheds
Funding - Private land rights
- Funding for water development opportunities
- Private funding
- Industry contribution
- Rehab of existing conveyance systems (old ditches)
- WWDC
- Partnerships with Feds
- Watershed groups (defined users)
- More funding for watershed protection (State)

5 of 5
Issues identified in the Powder/Tongue River Basin
Category Issues Activities/Projects
Funding (cont.) - Legislature
- More Federal funding
- Single species groups (Ducks Unlimited)
- Water futures
- Private systems providing water for payment
- Interstate water sales and leasing
- The Nature Conservancy (TNC)
- Cost/benefit analyses
- Trout Unlimited
- Wildlife and conservation organizations
NOTE: Revisions were made to this list per comments from BAG members at meeting held 12-7-2005

SNAKE/SALT RIVER BASIN

SNAKE /SALT RIVER BASIN PLAN
EXECUTIVE SUMMARY
WYOMING WATER BASIN PLANNING PROGRAM
WYOMING WATER DEVELOPMENT COMMISSION
June, 2003
Prepared By:
SUNRISE ENGINEERING,INC.
Afton, WY 83110
In Cooperation with:
Boyle Engineering, Inc.
BBC Consulting, Inc.
Lakewood, CO 80228 Denver, CO 80209
Hinckley Consulting
Fassett Consulting
Laramie, WY 82070 Cheyenne, WY 82003
Rendezvous Engineering
Nelson Engineering
Jackson, WY 83001 Jackson, WY 83001

Executive Summary
INTRODUCTION
The 2001 Wyoming Legislature authorized the Wyoming Water Development Commission
(WWDC) to complete the Snake/Salt River Basin portion of the State Water Plan. According to
the WWDC, the river basin planning process has the following goals:
• Provide accurate, contemporary water information to enable state and local decision
makers to manage water resources efficiently.
• Maintain an inventory of water data for use by various state agencies.
• Assist the Legislature and the Governor in developing effective state water policies to
protect Wyoming's water and promote responsible development.
• Give Wyoming citizens access to the water information they need to deal with water
issues at the grassroots level.
• Project future water demands so the state can prepare for the effects of growth.
• Bring Wyoming's water planning program up to par with other Western states.
• Provide the state with information to assist in responding to the mandates of federal
legislation and regulation.
• Protect Wyoming's water resources from downstream competitors.
Numerous technical memoranda were created as the background to the final report. All topics
discussed in this report are covered in detail in the technical memoranda. These documents, as
well as other Wyoming river basin plans, can be found electronically on the Wyoming State Water
Plan homepage at http://waterplan.state.wy.us/.
The initial Snake/Salt River Basin Advisory Group meeting was held May 15, 2001 in Jackson.
At that time the Basin Advisory Group (BAG) was formed, consisting of over 30 citizens from
throughout the basin. The members represent a variety of interests, such as agriculture, industry,
environmental, government and recreation. Their knowledge and input was invaluable to the creation
of this basin plan and their efforts are much appreciated.
BASIN DESCRIPTION
The Snake River Basin is part of the Columbia River drainage that flows to the Pacific Ocean.
The Snake/Salt River basin in Wyoming is a portion of the headwaters of the Snake River, and
contains all of the Snake Headwaters, Gros Ventre, Greys, and Hoback sub-basins, as well as portions
of the Salt, Palisades, Teton, Lower Henry's, and Upper Henry's sub-basins. The Wyoming
portion of the Snake/Salt River basin covers approximately 5,100 square miles. A map of the
Snake/Salt River basin planning area can be found in Figure 1. The Snake River is one of the
major rivers of the West, flowing from Wyoming across Idaho before converging with the
Columbia River in Washington. The basin covers all of Teton County and portions of Lincoln,
Sublette, and Fremont Counties. The basin includes all of Grand Teton National Park, as well as
a portion of Yellowstone National Park.
Snake/ Salt River Basin Plan
Page 1

Executive Summary
Climate in the basin can be quite variable due to the range of elevation that is present. Of the
locations with recorded data, the average annual precipitation ranges from approximately 17 inches
in Jackson to over 28 inches at the Snake River site near Flagg Ranch. Examples of precipitation
at other populated areas include over 18 inches at Afton, nearly 24 inches at Alta, and over
20 inches at Boundurant. Mountainous areas typically have much higher average annual precipitation,
with some areas at over 60 inches at the Tetons. The majority of the precipitation falls
in the winter as snowfall, which then melts and flows as runoff during the spring and summer
months.
The high elevation of the mountain valleys in the basin results in a fairly short growing season
capable of supporting only native hay, alfalfa, and small grains. The average growing seasons are
139 days and 144 days for Jackson and Afton respectively. Also, the relative lack of precipitation
during the summer results in a need for crop irrigation in order to maximize crop production.
The main water features in the Snake/Salt River basin are the rivers themselves. The Snake River
is the largest in the basin, and its sizeable tributaries include the Buffalo Fork, Gros Ventre, and
Hoback Rivers. The Salt and
Greys Rivers are also tributary to
the Snake, and join the main river
at Palisades Reservoir.
Numerous streams feed each of
these rivers on their journey
through the basin.
There are many natural lakes in
the basin, which include
Shoshone, Heart, and Lewis
Lakes in Yellowstone National
Park. There are many sizeable
lakes in Grand Teton National
Park, including Jackson, Jenny,
Leigh, Two Ocean, and Emma
Matilda Lakes. Many smaller lakes are located throughout the basin, generally on Forest Service
lands.
THE SNAKE RIVER COMPACT & ROXANNA DECREE
Use of water in the state is subject to Wyoming water laws as well as interstate compacts and
court decrees. These documents govern how water is diverted and used, particularly in times of
low supply. The Snake River Compact, negotiated by the representatives of both Idaho and
Wyoming with participation of a representative of the United States, was signed on October 10,
1949. The compact divided the waters of the Snake and Salt River watersheds between the states
Snake/ Salt River Basin Plan
Page 2

Executive Summary
of Idaho and Wyoming. The compact recognizes, without restriction, all existing water rights in
Wyoming and Idaho established prior to July 1, 1949. It permits Wyoming unlimited use of water
for domestic and stock watering purposes, providing stock water reservoirs shall not exceed 20
acre-feet in capacity. The compact allocates to Wyoming, for all future uses, the right to divert
or store 4% of the Wyoming-Idaho state line flow of the Snake River. Idaho is entitled to the
remaining 96% of the flow. The use of
water is limited to diversions or storage
within the Snake River drainage basin
unless both states agree otherwise. The
compact also provides preference for
domestic, stock and irrigation use of the
water over storage for the generation of
power.
The Roxanna Decree is a shorthand name
for a 1941 United States District Court decision
resolving an interstate dispute between
water users in Wyoming and Idaho diverting
from Teton Creek and South Leigh
Creek. This decree adopted a stipulation of agreement entered into by the water user parties located
within Wyoming and Idaho, dated March 20, 1940.
PALISADES RESERVOIR COMPACT
The Palisades Reservoir contract provides Wyoming with 33,000 acre-feet (AF) or 2.75% of the
1,200,000 AF of active storage space in Palisades Reservoir. Wyoming is entitled to the water
accruing to this space in priority for a variety of purposes, including the compact replacement
storage space obligations, subcontracting the use of storage water to others and to maintain
instream flows and lake levels within Wyoming, through an exchange. Wyoming is contractually
treated for the most part like any other storage spaceholder in Palisades Reservoir under contract
with the Bureau, with the same general rights and obligations for the use, accounting, and
administration of the storage space.
AGRICULTURAL WATER USE
Agricultural water uses consume more water than any other use in the Snake/Salt River basin.
Agricultural uses mainly consist of irrigation of crops by either flood or sprinkler irrigation. The
vast majority of irrigation water is diverted from surface water sources, although there are small
areas served by ground water sources.
The types of crops grown in the Snake/Salt River basin are greatly influenced by climate. Typical
farmland in the basin is located in the high mountain valleys where there is low to moderate pre-
Snake/ Salt River Basin Plan
Page 3

Executive Summary
cipitation. These valleys have relatively short growing seasons and long winters with significant
accumulations of snow. Hard frosts have been observed in every month of the year. Because of
these conditions typical crops consist of alfalfa, small grains (mainly barley with some oats), and
native hay and grass. In addition to these crops, the portion of the study area that is in the Teton
River sub-basin also produces a small amount of potatoes.
MUNICIPAL AND DOMESTIC WATER USE
The four municipalities and 46 other public water systems in the basin obtain their water supply
from ground water wells or springs. There are no entities in the basin that obtain water from surface
water sources. For the remaining population that obtains domestic water from other sources
such as individual wells, ground water is also used exclusively.
INDUSTRIAL WATER USE
The use of water for industrial purposes is very limited in the Snake/Salt River Basin. Typical
industries from other parts of Wyoming such as coal mines, trona mines, and natural gas and oil
wells are not found in the basin, and the communities in the basin are relatively small and do not
have large industrial facilities. The facilities that do exist are generally related to food processing
and production, with most of the use having its roots in the dairy industry. Water for industrial
use is mainly supplied through or in conjunction with municipal water systems.
RECREATIONAL WATER USE
Recreation is generally considered a non-consumptive use of water. There is a significant amount
of recreational activity within the
Snake/Salt River basin. People travel
from around the world in order to boat,
fish, ski, camp, and hike in this part of
Wyoming. Tourism has a major impact
on the economies of the communities in
the basin, with much of the tourism
being linked to Grand Teton and
Yellowstone National Parks. Many of
the draws of these parks are water related,
with the most notable water features
within the basin being Jackson Lake
and the Snake River. The Snake River
is also a major draw throughout the
Jackson Hole area as well as through
the Snake River Canyon toward Alpine,
sometimes referred to as the Grand
Snake/ Salt River Basin Plan
Page 4

Executive Summary
Canyon of the Snake River. Thousands visit the river each year for rafting, kayaking, fishing, and
other activities. In addition to the Snake River and Jackson Lake, there are numerous rivers,
streams, and lakes throughout the basin that are used for recreation. Other activities that utilize
or require water in some form include waterfowl hunting and winter sports such as skiing.
ENVIRONMENTAL WATER USE
Water features such as rivers, streams, and lakes are an integral part of the landscape and environment
in the Snake/Salt River basin. Among the various uses of water studied as part of the
basin plan, this report also looks at the use of water for environmental purposes. Many of these
uses are controlled by man to maintain or improve existing conditions, while others, such as wetlands,
may occur naturally and are subject to management by various means. Environmental uses
and topics covered in the basin plan include maintenance flows, wetlands mapping and projects,
Snake River restoration, cutthroat trout management, big game habitat, downstream salmon
recovery efforts, instream flow water rights, and water quality.
MAJOR RESERVOIRS
All of the major reservoir facilities in the Snake/Salt River basin are owned and managed by the
U.S. Bureau of Reclamation for irrigation and hydropower production in Idaho. Jackson Lake
Dam and Grassy Lake Dam are managed as part of the Minidoka Project, which provides irrigation
water for over 1 million acres of farmland in Idaho. Palisades Dam, part of the Palisades
Project, is also managed in conjunction with the Minidoka Project.
AVAILABLE SURFACE WATER
Surface water availability in the Snake and Salt River basins is a matter of physical supply, availability
with respect to others' uses, and basinwide compact limits. In both the Salt and Snake
basins, a new appropriation in a tributary basin will be limited by local supply, and without storage,
may be severely limited in some months of the year. On the other hand, overall water supply
in the basin greatly exceeds current use. On the main stems of both rivers, and in the larger tributaries
of the Snake, the compact is more limiting than physical supply relative to existing
demand. There are locations and months in which the entire annual compact allowance could be
diverted within one month. Thus the supply available to any given proposed use varies greatly
across the basin, and could be impacted by concurrent development of the compact allowance
elsewhere in the basin. Table 1 summarizes surface water availability.
AVAILABLE GROUND WATER
Ground water is a relatively abundant resource in the Snake/Salt River basin. Subsurface materials
are saturated with water from the water table, a relatively short distance below land surface
Snake/ Salt River Basin Plan
Page 5

Executive Summary
in most areas, to the depth at which there is no significant porosity to contain ground water, e.g.
the crystalline basement rocks underlying the entire Snake/Salt River basin and forming the visible
core of the highest mountains. The volume of pore space in this material represents the volume
of ground water and is likely on the order of 100's of millions of acre-ft. Much of this water
is of unusable quality (e.g. due to great depth) or is contained in formations from which ground
water cannot be extracted at useful rates (e.g. thick shale units), so the useable ground water
resource is vastly smaller than the total ground water in storage.
Considering only the alluvial aquifer (covering approximately 400 mi 2 ) in the Snake/Salt River
basin, and assuming an average saturated thickness of 200 feet and an effective porosity of 20%,
a volume of 10 million acre-ft of useful ground water in storage is calculated. Were ground water
a static, nonrenewable resource, like coal, this volume might approximate the developable
resource.
Ground water is a very dynamic resource, particularly ground water of high quality occurring at
depths feasible for development. Data suggest an average annual recharge rate of approximately
4 inches = 1 million ac-ft/yr spread across the 4700 mi 2 of the Snake/Salt River basin. The base
flows of the Salt and Greys Rivers (i.e. the streamflow that is sustained by ground water input
through the period of the year without significant precipitation input) suggest average ground
water output of 250 and 350 ac-ft/mi 2 /yr, respectively. (The Snake River basin below Jackson
Lake is not considered due to the impact of reservoir modulation on base flows.) Applying a value
of 300 ac-ft/mi 2 /yr to the entire basin suggests a total ground water output of 1.5 million ac-ft/yr,
roughly comparable to the recharge-based estimate. Of course, development and consumption of
this "available" ground water would leave the streams of the Snake/Salt River basin dry through
much of the year.
A more detailed, ground water-model based mass balance for the alluvial aquifer between Jackson
Lake and Hoback Junction was developed by San Juan and Kolm (1996). They estimated total
recharge of approximately 50,000 acre-ft per year, with 25,000 acre-ft per year of ground water
discharge through evapotranspiration and 25,000 acre-ft per year of discharge to streams.
In any case, the inescapable requirements of mass balance mean that additional ground water consumption
causes either a decrease in ground water storage (declining ground water level/pressure),
a decrease in consumption elsewhere in the hydrologic system, or depletion of surface
water. There is little indication of widespread reductions in ground water levels in the study area
(although long-term data are sparse).
WATER DEMAND PROJECTIONS
Water demand projections were developed utilizing an economics based approach. Using a planning
period of 30 years, the various aspects of water use were projected for high, mid, and low
Snake/ Salt River Basin Plan
Page 6

Sub-basin Gage flow Depletions
DRY YEAR
Table 1
Summary of Compact Limits to Surface Water Development
(values in acre-feet)
Post-compact
fraction
Post-compact
depletions
!Storage for
Idaho use
Subject to Compact
allocation
Snake 2,420,790 41,607 0.1300 5,409 -277,000 2,149,199
Salt 376,250 54,547 0.0400 2,182 0 378,432
Greys 288,336 0 N/a 0 0 288,336
Total subject to allocation: 2,815,967
Allowable diversions (4%): 112,639
Current post-compact diversions (depletion x 3): 22,772
Remaining allowance: 89,866
NORMAL YEAR
Snake 3,303,870 37,789 0.13 4,913 0 3,308,783
Salt 618,154 58,502 0.04 2,340 0 620,494
Greys 478,225 0 N/a 0 0 478,225
Total subject to allocation:: 4,407,501
Allowable diversions (4%): 176,300
Current post-compact diversions (depletion x 3): 21,758
Remaining allowance 154,542
WET YEAR
Snake 4,547,986 37,664 0.13 4,896 0 4,552,882
Salt 854,495 61,015 0.04 2,441 0 856,936
Greys 671,481 0 N/a 0 0 671,481
Total subject to allocation: 6,081,299
Allowable diversions (4%): 243,252
Current post-compact diversions (depletion x 3): 22,011
Remaining allowance: 221,241

Executive Summary
growth scenarios. The high scenario incorporates the most growth in each of the key sectors that
could potentially occur over the forecast horizon. The low scenario embodies the lowest growth
(or largest contraction) reasonably likely to occur. The mid scenario represents the most realistic
level of growth likely to occur. Following discussion of the various projections, Table 2 provides
a summary of projected water use.
AGRICULTURAL USE PROJECTIONS
Regarding agricultural water use, the high scenario projects a slight increase mainly due to a
slight increase in irrigated lands. The low scenario projects a significant decrease as agricultural
lands are converted to residential use. The mid scenario projects a 13 percent decline in irrigated
lands and a slight decline in the dairy industry, thus resulting in a slight decrease in agricultural
water use.
MUNICIPAL/DOMESTIC USE PROJECTIONS
The job market and economy in the Snake/Salt River basin are mainly driven by tourism.
Therefore growth projections
regarding municipal and domestic
water use are tied to projections
in tourism activity. The
high scenario projects growth in
tourism during summer, winter,
and shoulder seasons, which in
turn results in an increase in both
seasonal and year round residents.
As a result, the population
roughly triples during the planning
period. The low scenario
projects virtually no growth due
to a prolonged economic downturn,
thus resulting in only a small population increase. The mid scenario projects modest growth
in tourism, resulting in a projected population of nearly double that of today.
INDUSTRIAL USE PROJECTIONS
Due to the relatively small amount of industry in the basin, projections of future use have very
little impact on overall future water use projections. The high scenario assumes a very slight
increase in use, while the low scenario utilizes a decrease in industrial activity. The mid scenario
assumes that current industrial use levels remain relatively unchanged throughout the planning
period.
Snake/ Salt River Basin Plan
Page 8

Executive Summary
RECREATIONAL USE PROJECTIONS
Recreational water use in the basin is very significant, although a majority of this use is considered
non-consumptive. Water that is consumed for recreational activities is mainly a result of golf
course irrigation in the summer and snowmaking in the winter. The high scenario assumes four
additional golf courses in the basin as well as an expansion of snowmaking facilities. The low
scenario maintains current levels throughout the planning period. The mid scenario considers two
new golf courses and modest snowmaking expansion.
ENVIRONMENTAL USE PROJECTIONS
This study restricted the definition of environmental uses to include only those associated with
efforts aimed at restoring, maintaining, or improving the environmental services provided by the
water resources. This resulted in two main categories consisting of instream flows (through maintenance
flows or water rights) and wetland projects. The high scenario assumes that all planned
instream flows and wetland projects are completed, resulting in an increase of nearly 400%. The
low scenario includes a reduction in maintenance flows, and thus an overall reduction in use. The
mid scenario sees an approval of some instream flow rights, as well as half of the proposed wetland
projects. This results in an increase of approximately 300%. It must be noted that instream
flows represent a significant use of water, and the flow rates assumed for this report could change
drastically in the future. As a result, the projected uses presented in the report cover a very broad
range. Also, while the water required for environmental uses must be available at the project location,
this water can be used for other purposes downstream. This, in essence, makes these uses
non-consumptive, and so they are not included with the other projected water uses.
TABLE 2. SUMMARY OF CURRENT AND PROJECTED WATER USE
Use Current Use 2032 Projected Use (Acre-Feet/Yr)
Low Mid High
Agricultural 122,427 95,101 107,446 128,529
Municipal 6,581 7,240 11,543 18,558
Industrial 48 24 48 49
Recreational 945 945 1335 1576
Total 130,001 103,310 120,372 148,712
FUTURE WATER USE OPPORTUNITIES
The long list of future water use opportunities was created with input from the Snake/Salt River
Basin Advisory Group. Any and all input was welcome, and a wide variety of issues was discussed
while adding items to the list, including past studies. The long list ended up with projects
for uses such as irrigation, hydropower, wetlands, water storage, recreation, and others.
Snake/ Salt River Basin Plan
Page 9

Executive Summary
Following the creation of the long list the resulting list was reviewed in order to reduce the list to
a collection of potential water use projects. Some items on the long list, while they may be worthy
of further discussion in other circles, did not warrant further investigation as part of this basin
plan. Also, projects that appeared to have a low probability of support or feasibility were
dropped.
The short list of future water use opportunities consists of the remaining projects from the long
list. The short list projects were then reviewed by the basin planning team and evaluated based
on the short list criteria.
A list of criteria used to evaluate the short list was created as part of this basin plan. Similar criteria
have been used on all of the previous basin plans, although some changes were made to better
fit the situation in the Snake/Salt River basin. For example, political acceptance was looked
at in addition to public acceptance, and environmental constraints were reviewed due to the large
amount of federal land and the constraints placed on those lands through environmental laws.
Also, a criteria regarding multiple use was added.
The following criteria were used to evaluate the short list of future water use opportunities. Each
item was scored on a scale of 1 to 10, with 1 being not feasible and 10 being very feasible.
• Water Availability
• Financial Feasibility
• Public & Political Acceptability
• Available Users/Sponsors
• Legal & Environmental Constraints
• Multiple Use Feasibilit y
Evaluation of each project on the short list using the above described criteria resulted in a final
number or score. Also, the Short List was broken into sub-basins, as issues that can effect the
evaluation of a project in the Snake River basin will be different than those in the Salt River basin.
Legal and institutional constraints, such as federal environmental laws, federal land issues,
Wyoming environmental quality laws, Wyoming water law, interstate compacts, and court
decrees were also reviewed for their impact on future development in the Snake/Salt River basin.
In the last decade the Snake/Salt River basin has experienced significant population growth. It is
reasonable to expect this pattern to continue. This growth combined with the availability of water
results in opportunities for the citizens in the basin to more fully utilize these water resources in
the future.
Snake/ Salt River Basin Plan
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1 of 2
Issues identified in the Snake/Salt River Basin
Issues
Current Status
Water Quality - Flat Creek Watershed Enhancement Project
- Fish Creek Groundwater Study
- Monitoring program - Teton Co. Conservation District
- DEQ Subdivision reviews
- NPS long term water quality monitoring program (start in Spring of 2007)
- Teton Co. and/or Teton Co. Conservation Dist. Watershed plan (???)
- BTNF water quality projects
Environmental Concerns - Alpine Wetlands Project
- Snake River Resource Management Plan - BLM
- Jackson Lake Dam operations
- Upper Snake River Restoration Project
- Instream flows - channel maintenance and other environmental issues
Recreation - Snake River Fund
- Wild and Scenic Campaign
- Jackson Lake Dam operations
- Water as a visual resource
- Fishing and other water recreation (uses and impacts)
- White water rafting
Agriculture - Canal Modernization/North Canal Project (Stephen Smith, Aqua Engineering, Inc.)
- Incentives for more efficient irrigation systems (conservation)
- Traditional uses of agricultural land moving to untraditional uses
Other Uses/Consumptive - Jackson Lake Hydroelectric Project (Dr. Vince Lamarra, Ecosystems Research, Inc.) - still an ongoing issue??
- Alpine Master Plan
Water Law/Compacts
Growth - Growth in Teton County, Idaho
- Growth impacts in basin (increase in need for water and wastewater systems)
- Economic Development in the Basin (is there water available?)

2 of 2
Issues identified in the Snake/Salt River Basin
Fisheries - Protect instream flows
- Fisheries Management of the Snake and Salt River Basins (Tracy Stephens)
- Studies of Snake River Cutthroat Trout in the Salt River (Travis Sanderson)
- Inventory from Palisades Dam to headwaters of Snake (species identification, habitat identification, etc.)
- Mark Novak - Utah State University
- Temporary change in use to instream flow
- illegal fish introductions
- petition for listing of the Yellowstone cutthroat trout
Wastewater - Wastewater treatment and reuse
Other - Snake River Operations
- Drought and related issues
- Water 2025
- WYDOT issues in the basin (avalanche threats)
- Weather Modification Feasibility Study
- overlapping authorities, jurisdictions and permitting authorities on Snake River (executed MOA)
NOTE: Issues listed in blue are those that were added per the BAG at the meeting held 11-9-2005

WIND/BIGHORN RIVER

WIND/BIGHORN RIVER
BASIN PLAN
EXECUTIVE SUMMARY
Land Ownership
1:24,000-scale
PREPARED FOR THE:
Wyoming Water Development Commission
BY:
BRS, Inc.
IN ASSOCIATION WITH:
MHW, Lidstone and Associates, TriHydro Corporation
Donnell and Allred Inc., Water Rights Services LLC
October 2003

Acknowledgements
The BRS team would like to acknowledge the assistance of several individuals, groups and agencies that
contributed to the Wind/Big Horn Basin planning process.
The Wind/Big Horn River Basin Advisory Group
The Wyoming Water Development Office River Planning Staff
The Wyoming Resources Data System
The Wyoming State Engineer’s Office
The Wyoming Department of Environmental Quality
The Wyoming State Geological Survey
The University of Wyoming Spatial Data and Visualization Center
The Wyoming Game and Fish Department
The Wind River Indian Reservation
The Wyoming Department of State Parks and Cultural Resources
The U.S. Department of the Interior, Bureau of Land Management
The U.S. Department of the Interior, Geological Survey
The U.S. Department of the Interior, Bureau of Reclamation
As well as those who gave presentations to the Wind/Big Horn Basin Advisory Group.
Barry Lawrence, Wyoming Water Development Commission
Greg Kerr, University of Wyoming
Dave Taylor, Wyoming State Parks
Dave Wilson, Wyoming State Parks
Todd Stevenson, Wyoming State Parks
John Lawson, U.S. Bureau of Reclamation
John Barnes, State Engineer’s Office
Steve Yekel, Wyoming Game and Fish
Robin Gray, Wyoming Resources Data System
Roger Bower, Wyoming Business Council
Bob Baker, Mayor of the Town of Dubois
Chuck Harnish, Department of Environmental Quality
Reg Phillips, Dubois/Crowheart Conservation District
Jan Curtis, Wyoming State Climatologist
Myron Brooks, U.S. Geological Survey
Ron Vore, Wyoming Water Development Commission
Phil Ogle, Wyoming Water Development Commission
Jeri Trebelcock, Popo Agie Conservation District
Joe Deromendi, Wyoming Game and Fish Department
Lee Craig, Park County Executive Director, FSA/USDA
Dr. Alan Gray, University of Wyoming Extension and Research Center
Bryant Startin, Shoshone Irrigation District
Grant Stumbough, Wyoming Department of Agriculture
Sue Lowry, State Engineer’s Office
Gary Collins, Tribal Water Engineer
Loren Smith, State Engineer’s Office
Steve Gray, University of Wyoming
Dave Peterson, U.S. Geological Survey
Ed Conning, Beartooth Paddlers

EXECUTIVE SUMMARY
Authorization
The Wind/Bighorn Basin (WBHB) Plan is one of a series of River Basin Plans prepared, or
currently being prepared, for the Wyoming Water Development Commission (WWDC). The
2001 Wyoming Legislature authorized the Water Development Commission to complete this
specific basin plan as part of the overall State Water Plan. The study area is shown on the front
cover. River Basin Plans have been completed for the Bear River Basin, Green River Basin, the
Northeast Wyoming River Basins and the Powder/Tongue River Basins. The Snake/Salt River
Basin Plan is being completed contemporaneously with the WBHB Plan. The Platte River Basin
planning process is scheduled to begin in 2003 and is the final of the basin plans. It is the intent
of the WWDC that the information presented in the plan documents will be reviewed and
updated every five years to reflect changes and new concerns.
Project Scope
The WBHB includes the Wind River, Clarks Fork of the Yellowstone and Bighorn River Basins
and focuses on major water uses including agricultural, municipal, domestic, industrial,
environmental and recreational, and water use from storage. Figure 1 shows the area included in
the basin plan. The basin plan documents current water uses, surface and ground water
availability, and projects future uses and/or demands for water based on various planning
scenarios. In addition, institutional and legal constraints governing water development and
management were reviewed and are summarized within this report. Based on this information,
potential water development projects were identified. Subsequent to the initial scope of work, a
review of power generation opportunities in the WBHB area was requested by the WWDC,
including both hydropower and fossil fuel power generation.
Basin Description
The Wind/Bighorn Basin planning area includes all of Big Horn, Park, and Hot Springs Counties,
about 95% of Washakie County, approximately 85% of Fremont County, roughly 10% of Teton
County, and the over 2 million acres of the Wind River Indian Reservation. Also included, are
small, relatively undeveloped portions of northwestern Natrona and western Johnson Counties.
Approximately 80% of Yellowstone National Park is included in the planning area. Regionally,
the planning area lies within the Missouri River drainage system and covers an area of
approximately 20,500 square miles of federal, state, and privately owned land in central and
northwestern Wyoming. Only 30% of the land within the planning area is privately controlled.
Elevations in the planning area are variable because the Wind River and Bighorn Basins are
bordered by high alpine mountain ranges. Elevations range from roughly 3,500 feet above sea
level, where the Bighorn River crosses the State line into Montana in Big Horn County, to 13,804
feet at the summit of Gannett Peak in Fremont County. The climate varies primarily as a
function of elevation, and ranges from semi-arid continental in the WBHB interiors to humid-
Executive Summary - 1

alpine in the bordering mountain ranges. Annual precipitation varies from 6 to 8 inches in the
WBHB interiors, up to 60 to 70 inches along the peaks of the bordering mountain ranges. Most
of the planning area receives the majority of its precipitation during the winter as snowfall, but
the interiors primarily receive precipitation from occasional spring and summer thunderstorms.
Unique water-related environmental features of the WBHB include the glaciers of the Wind
River mountain range, a section of the Clarks Fork of the Yellowstone is designated as a “Wild
and Scenic” river, Sink’s Canyon, the Thermopolis Hot Springs, and the numerous natural
wonders of Yellowstone Park.
Basin Advisory Group Meetings (BAG)
Basin Advisory Group (BAG) meetings were held every other month between May 2001 and
April 2003. The meetings were structured to inform the BAG and the public of issues within the
WBHB and to solicit input in the basin planning process. The BAG, comprised of a broad range
of interests including various local governments, The Wind River Indian Reservation, water
conservation districts and representatives from agricultural, industrial, recreational,
environmental and economic interests, provided their opinions on water planning issues,
planning products, and assisted in the planning process. More information on the BAG meetings
can be found on the web at (http://waterplan.state.wy.us,) including the meeting records, the
reference notebook, and select presentations.
Compacts and Decrees
Within the Wind River, Clarks Fork and Bighorn Basins, surface water usage and flow is
regulated by the Yellowstone River Compact of 1950 and the GENERAL ADJUDICATION OF
ALL RIGHTS TO USE WATER IN THE BIG HORN RIVER SYSTEM.
The Yellowstone Compact allocates unappropriated waters (surface), after meeting existing
water rights (1950) and supplemental supply for existing rights, as follows:
Wind River/Big Horn
Clarks Fork
80% Wyoming, 20% Montana
60% Wyoming, 40% Montana
The Big Horn General Adjudication awarded the Shoshone and Arapaho tribes of the Wind River
Indian Reservation (WRIR) the right to 500,000 acre feet of surface water annually with a
priority date of 1868. Within this allocation some 209,000 acre feet is reserved for future project
development. For ground water rights, there are no WRIR reserve water rights.
Land Ownership
As depicted on the cover, the WBHB includes the 1.5 million acres in the WRIR and some 14.1
million acres of land, the majority of which is publicly owned. Public lands consist of 600,000
Executive Summary -3

acres of state land and 8.9 million acres of federal land, dominantly BLM and U.S. Forest
Service.
Current Water Use
Figure 2 provides and overview of water use in the WBHB (from 2000 statistics). Water use is
dominated by Agricultural use, which in turn is dominated by crop irrigation, as compared to
grazing and other agricultural activities.
Figure 2 Overview of Water Use
2% 10% Irrigation
6%
Industrial
Municipal/Domestic
82%
Use From Storage
Agricultural
The Wyoming State Engineer’s Office (SEO) records for Water Division No. III show some
450,000 acres of land historically irrigated in the WBHB. Of this total, approximately 344,000
acres are reported as irrigated by the U.S. Department of Agriculture (USDA). Irrigated lands
mapping, completed as part of this study, found some 560,000 acres of irrigated or potentially
irrigated lands, based on 1999 aerial color infrared mapping. Water rights attribution associated
with the irrigated lands mapping indicated about 600,000 acres with water rights at the time of
the investigation. Finally, the proposed tribal futures projects could add approximately 53,000
Executive Summary -4

acres. Given these variations, surface water use and availability was modeled to consider
Historical Diversions (~450,000 acres irrigated), Full Supply (~600,000 acres irrigated), and Full
Supply with Futures (~653,000 acres irrigated). Crop Irrigation Requirements (CIR) were
determined based on crop type and climatic location within the WBHB. Typical crops include:
alfalfa, beans, corn, other hay crops, spring grains, sugar beets, and other minor crops. Based on
the CIR evaluation, the Full Supply consumptive use was estimated to be 1,165,000 acre feet per
year (approximately 1.94 acre feet per acre per year). Figure 3 depicts the Irrigated Lands in the
WBHB.
Executive Summary -5

Municipal and Domestic
According to the U.S. Environmental Protection Agency (EPA), there are currently 58 active
municipal and non-municipal community public water systems in the Wind/Big Horn Basin.
These systems are capable of storing more than 36.7 million gallons of water obtained from
rivers, streams, wells, reservoirs, and lakes to serve more than 59,000 people, or roughly 87% of
the WBHB's population. The average daily municipal water use for the Wind/Bighorn Basin is
approximately 12.2 million gallons per day (MGD), or roughly 207 gallons per day per person.
Surface water is utilized to supply 68% of the average water use, with the remainder from ground
water sources.
Based on rural domestic and non-municipal public water system usage, total domestic water
usage for the planning area has been estimated to range from 6.5 to 10.4 MGD. Almost 83% of
rural domestic water supplies are derived from wells located in Fremont and Park Counties. For
the 34,287 people who use the 115 non-municipal public water systems, domestic water usage is
estimated at 2.57 MGD. Both ground and surface water supplies are utilized to meet daily
domestic demand. Within the WBHB, roughly 26% of the domestic use is supplied by surface
water sources, while 74% is supplied by ground water.
Industrial and Mining
Most industrial water users in the WBHB are comparatively small companies, with relatively low
water needs. In most cases, these companies draw their water from municipal systems, or from
their own wells. In many cases, the water used from wells for industrial purposes is not suited
for other uses, due to poor water quality. In summary, the permitted water rights for mining and
industrial uses in the WBHB total 92,241 acre feet/year or 82.4 MGD.
Environmental and Recreational
Environmental and recreational uses are for the most part non-consumptive uses. Environmental
and recreational uses are very important in the WBHB, with respect to socioeconomic impacts
and general contribution to Wyoming’s quality of life. In Wyoming, instream flow water rights
are currently the only specific water right for environmental purposes. The Wyoming Board of
Control has interpreted the use of instream flows for fisheries protection only. In the WBHB,
there is a total of 280,520 acre feet instream flow requirement permitted in portions of the Clarks
Fork of the Yellowstone, Tensleep Creek, Big Wind River, and Shell Creek. Applications for
another 277,716 acre feet are pending in portions of the Little Popo Agie, Medicine Lodge, and
Shoshone rivers. Other environmental uses include reservoir conservation pools, wetland and
riparian areas, and direct wildlife consumption.
Water Use from Storage
Within the WBHB there are 33 reservoirs with capacity is excess of 500 acre feet. The total
reservoir storage capacity is approximately 3 million acre feet. The estimated annual net
Executive Summary -7

evaporative loss for these reservoirs is 138,711 acre feet. A complete table of reservoirs can be
found in the Wind/Bighorn Final Report, chapter 2, page 44.
Conservation
Irrigation is the largest single use of water in the WBHB and irrigation methods vary in
efficiency, with sprinkler irrigation generally considered most efficient, followed by gated pipe
and lined ditches. Cost sharing programs for conservation purposes are available from several
governmental agencies. The WWDC has sponsored and continues to sponsor projects with water
conservation as a major component.
Municipal/domestic water conservation measures are limited in Wyoming. Of the 188 systems
reporting to the WWDC in 2002, only 29 report having tiered rates as a water conservation
measure, 24 have ordinances prohibiting the wasting of water, 2 report providing subsidies for
efficiency, and 25 entities have some other form of water conservation measures in place.
Surface Water Availability
An important part of the river basin planning process is to estimate water availability within the
river basins for future development and use. The availability of surface water was determined
through the construction and use of a spreadsheet simulation model that calculates water
availability based on the amount of streamflow less historical diversions, compact requirements
and minimum flows.
Previous reports have indicated that some 1,600,000 acre feet of surface water in the
Wind/Bighorn Basin and some 424,000 acre feet of surface water in the Clarks Fork Basin is
unappropriated. The findings of this investigation substantially support these published figures,
as shown in Table 1. However, despite this apparent surplus, many areas within these basins
chronically experience water shortages.
Table 1 Calculation of Wyoming Portion of Unallocated Flow
Clarks Fork of the Yellowstone Bighorn River
Dry Normal Wet Dry Normal Wet
Year Year Year Year Year Year
Gaged Flow (ac-ft) 491,713 733,406 1,137,418 1,911,049 2,778,269 3,591,471
Adjusted Flow (ac-ft) 498,664 740,007 1,144,083 1,686,523 2,559,384 3,382,968
Wyoming Portion of Unallocated 299,199 444,004 686,450 1,349,218 2,047,507 2,706,375
Flow (ac-ft)
Wyoming Portion of Unallocated N/A N/A N/A 1,099,218 1,797,507 2,456,375
Flow (ac-ft) minus Futures Projects
Notes:
(1) Based on 1973 – 2001 data.
Executive Summary -8

Table 2 presents a summary of the shortages within each sub-basin model for the Full Supply
condition (approximately 600,000 irrigated acres). Shortages are more severe in the Wind River
Basin than in the other basins, with the exception of the Owl Creek Basin, especially in dry years.
Shortages occur on the mainstem of the Wind River and Little Wind River, and in most
tributaries. The Owl Creek Basin experiences shortages during all hydrologic conditions and at
nearly every diversion point. In the remaining portion of the Bighorn Basin, shortages are
primarily on smaller tributaries. There are very few shortages on the mainstems of the Bighorn,
Shoshone, Nowood and Shell Creek. There are significant shortages on the mainstem Greybull
River, especially without the influence of the recently completed Greybull Valley Reservoir. It is
expected that this reservoir will alleviate most shortages in normal and wet years, with some
remaining shortages in dry years.
Table 2 Summary of Modeled Diversion Shortages – Full Supply
Full Supply
Diversion Shortages (ac-ft)
Shortages (percent)
Basin
(ac-ft) Dry Normal Wet Dry Normal Wet
Clarks Fork 106,293 30,402 18,786 11,645 29% 18% 11%
Yellowstone 0 0 0 0 0% 0% 0%
Sub-Total 106,293 30,402 18,786 11,645 29% 18% 11%
Upper Wind 933,909 192,930 54,067 43,948 21% 6% 5%
Little Wind 344,734 97,916 38,741 29,206 28% 11% 8%
Lower Wind 80,635 20,537 15,839 11,634 25% 20% 14%
Sub-Total 1,359,278 311,384 108,648 84,788 23% 8% 6%
Upper Bighorn 329,300 12,220 7,499 5,450 4% 2% 2%
Owl Creek 116,769 39,790 24,919 19,590 34% 21% 17%
Nowood 117,327 7,482 5,273 3,362 6% 4% 3%
Lower Bighorn 170,209 26,747 11,169 6,943 16% 7% 4%
Greybull 505,395 172,142 47,001 29,905 34% 9% 6%
Shoshone 829,711 29,097 18,348 9,801 4% 2% 1%
Sub-Total 2,068,711 287,478 114,210 75,050 14% 6% 4%
Total 3,534,282 629,263 241,644 171,483 18% 7% 5%
Notes:
(1) Shortages are for historical Full Supply Conditions without Futures projects.
(2) The modeled shortages do not include releases from Greybull Valley Reservoir.
Similarly, the Tribal Futures Projects were modeled with a Full Supply diversion requirement of
approximately 198,000 acre feet for those projects proposed within the Wind and Little Wind
Basins. The Futures Projects would increase shortages within the Wind River Basin, not
including the Popo Agie, by approximately 205,000 acre feet in dry years, 70,000 in average
years and 39,000 in wet years. The dry year value actually exceeds the diversion requirement
Executive Summary -9

ecause return flows for the North Crowheart Project accrue to the river at locations where they
cannot be re-diverted by downstream entities. Figure 4 depicts the Tribal Futures Projects and
the Irrigable lands in the WBHB.
Downstream of Boysen Reservoir, the model does not show any impacts. This is because
Boysen Reservoir acts as a “buffer” between the Wind and Bighorn Basins. More storage within
the reservoir can be used to meet downstream demands. The model shows, however, as time
progresses, there may be more difficulty in filling Boysen Reservoir if all of the proposed Futures
Projects are on-line. A more detailed carry-over storage analysis is required to analyze the full
affects of Futures Projects on storage in Boysen Reservoir.
Executive Summary -10

Ground Water Availability
Within the limits of the planning area, ground water is the primary source of water for many
uses. While the Madison and Wind River Aquifers represent the most utilized sources of
municipal supply, 13 aquifers have been identified as important water sources for different
reasons throughout the WBHB. Potential areas for future ground water development
(highlighted in green) are shown on figure 5. Based on recorded declines in water levels and
wellhead pressures in these areas near Hyattville and Riverton, the Wyoming State Engineers
Office may want to further investigate these areas and talk with local residents regarding the
necessity of establishing control areas at these locations.
Future Water Use
Table 3 provides a summary of projected future water use in 2030 for the WBHB. Subsequent
sections describe the general basis of this projection.
Table 3 Summary of Wind/Big Horn Basin Water Use Forecasts
Type of surface Water Current Use Projected Growth Scenario
Use
(Normal Year) Low Moderate High
Municipal and Domestic 20,600 20,600 21,900 26,500
Industrial 92,200 92,200 115,000 135,000
Agricultural 1,165,000 1,165,000 1,305,000 1,576,000
Evaporation (in-State) 140,000 140,000 140,000 140,000
Recreation
Non-Consumptive
Environmental
Non-Consumptive
Total 1,417,800 1,417,800 1,581,900 1,877,500
For purposes of the Wind/Bighorn Basin plan, three scenarios have been developed to simulate
potential future development within the WBHB planning area. Future agricultural development
was based on the irrigable lands and the proposed Tribal Futures projects. Future municipal and
domestic water demand is directly related to population projections. Industrial growth in most
sectors has remained flat or declined. Growth projections are based on the attraction of fossil
fuel power generation to the WBHB area to meet projected increased power demand for local
consumption. Although environmental and recreational demands on water availability are
expected to increase these are generally non-consumptive uses and do not impact the demand
projection. Similarly no change in water use from storage is currently projected.
Executive Summary -12

Identified Water Development Projects
Over 200 water development projects were identified, addressing existing and future water
shortages in the WBHB. Table 4 presents the “short list” of projects developed through the basin
planning process. The “short list” was developed through a scoring and ranking process based on
engineering, environmental, social and institutional factors. The list is not intended to be
inclusive or exclusive, but rather a representation of the broad scope of potential water
development projects in the WBHB.
Executive Summary -13

Figure 5
Potential Areas for Future
Ground Water Development
October 2003

Table ES-4 Short-List of Water Development Projects
Category Name of Project Description of Project Location of Project
I. MUNICIPAL
Type of Project:
New Source
Type of Project:
Distribution/
Storage Opportunities
Type of Project:
Conjunctive Use
Type of Project:
Water Management
Type of Project:
Water Conservation
II. AGRICULTURAL
Paleozoic Well Field
Construct Deep Aquifer Supply
Executive Summary -15
Regionalization: Lander/
Hudson/Riverton
Paleozoic Well Field Construct Deep Aquifer Supply Regionalization: W.R. Reservation
Regionalization: Hot Springs
Paleozoic Well Field Construct Deep Aquifer Supply County
Bighorn Regional
Joint Powers Board Storage Tanks/Transmission HotSprings/Washakie County
Tensleep/Hyattville
Storage Tanks/ Transmission Washakie County
Aquifer Storage
and Retrieval Alluvial Aquifer Augmentation Upper Wind River/Riverton Area
Ground Water
Administration of Future
Control District
Development
Riverton Area
Ground Water
Administration of Future
Control District
Development
Paintrock Anticline and Hyattville
Municipal Survey and Repair of
Leak Detection
Leaks
Basin-wide
Reuse of Grey Water
Non Potable Water Irrigation of Parks/Cemetaries Basin-wide
Type of Project: New Source
N one
Type of Project: Bull Lake Dam
Storage Opportunities Enlargement Reservoir Enlargement Big Wind River
Dinwoody
Lake
Enlargement Reservoir Enlargem ent Big Wind River
Type of Project:
Distribution
Steamboat New Reservoir
Big Wind River
Ray Lake
Reservoir Enlargement Little Wind River
Little Popo Agie-
Off Channel Site 5 New Reservoir
Little Popo Agie
Pumpkin Draw New Reservoir Owl Creek
Neff Park (Popo
Agie
Study) New Reservoir Popo Agie
Lake Creek New Reservoir Clarks Fork
Moraine Creek No. 1 New Reservoir Shell Creek
Ditch Headgate and
Popo Agie Master Plan Diversion Improvements Popo Agie Basin
Kirby Creek Watershed Stock Reservoirs Kirby Creek Basin
Type of Project: New Lands Riverton East Construct New Diversions/Ditches Wind River Basin
Type of Project:
Water Conservation
Type of Project:
Basin Transfer
Westside Construct New Diversions/Ditch es Big Horn Basin
Midvale/LeClair
Ditch Linings/
Riverton Valley
Conveyance Improvements Wind River Basin
Wind River
Ditch Linings/
Irrigation Project Conveyance Improvements Wind River Basin
Clarks Fork to
Greybull Drainage Storage and Pipeline Clarks Fork to Big Horn Basin
III. ENVIRONMENTAL Instream Flows Admin Minimum Flows Wind and Big Horn Basin
Minimum Reservoir Pools
Admin Reservoir Releases
Wind and Big Horn Basin
Watershed/Habitat Improv. Water Quality Impaired Streams Big Horn Basin
IV. CULTURAL and
RELIGIOUS Water Use by Tribes Coordinated Reservoir Releases Wind and Big Horn Basin

Power Study
The Wind/Bighorn River Basin Power Study was conducted to analyze the potential for both
hydropower and fossil fuel facilities within the WBHB. Several potential projects were analyzed
to determine the technical feasibility of the project and the economics of project development.
The gas turbine power plants were determined to be the most attractive option for new power
generation within the WBHB. However, if any reservoir were to be further evaluated for water
supply purposes, these evaluations should include a technical and economic analysis of the
potential for power generation. For development of any of the proposed projects, a sponsoring
group or agency would need to be identified and formed. More information on these projects can
be found in the Wind/Bighorn River Basin Power Study.
Summary
This document is intended to provide a useful compilation of water related data for the Wind
River, Bighorn, and Clarks Fork River Basins. The GIS and other electronic format components
of the project are intended to allow this database to grow as new data becomes available. It is
hoped that the completion of this river basin plan will foster discussion among potential water
users and state officials relative to water development in the WBHB. The data presented in the
basin report clearly shows that substantial water resources are available in the WBHB for
development, but that the distribution and availability of the water resources in the WBHB
relative to point of use is highly variable. Without future water projects, which address the
development, storage, and distribution of Wyoming’s water resources in the WBHB, chronic
water shortages in specific localities will continue.
References and Additional Information
A substantial portion of information collected and developed as part of this project was
developed as a Geographical Information System (GIS) product, which will be managed by
Water Resources Data System (WRDS). GIS products include, but are not limited to: irrigated
lands mapping and water right attribution; topography; climate; geology; hydrologic features and
boundaries; and various man-made features such points of diversion, storage, and distribution. In
addition, a surface water model for the entire WBHB was developed as a spreadsheet model in
the format requested by the WWDC Finally, detailed technical data and descriptions of each
component of the basin plan are provided in the Wind/Bighorn River Basin Plan Final Report
and associated Technical Memoranda prepared for this project.
The Final Report and associated Technical Memoranda are available through the WRDS,
(www.wrds. uwyo.edu), in either .PDF format or HTML format. A printed version is available
for checkout through the WRDS library.
Executive Summary -16

Page 1 of 1
Issues identified in the Wind/Bighorn Basin
Categories
Water Development/Economic
Current uses/Future uses
Recreation
Groundwater
Agriculture
Tribal issues
Water Storage/Hyropower
Municipal/domestic
CBNG discharge water
Current economic impact of all sectors
Tribal issues
Unappropriated water
Yellowstone River Compact issues
Discharge of CBNG water
Instream flow/non-consumptive uses
Marketing Buffalo Bill Water
Land use planning
Tribal issues
Water Storage
Fishing and water sports
Tourism
Tribal issues
Maintaining and developing
Industrial use
Tribal issues
Maintenance and improved efficiency/conservation
Water Storage
Unappropriated water
NOTE: Revisions were made to this list per comments from BAG members at meeting held 12-6-2005

Appendix B
WESTERN STATES SURVEY

EXECUTIVE SUMMARY OF
WESTERN STATES SURVEY
Framework Water Plan
October, 2006
Submitted to:
Wyoming Water Development Commission
Cheyenne, WY 82002
7 4 0 E A S T P E A R L A V E N U E , P o s t O f f I c e B o x 7 4 4 1 , J a c k s o n , W Y 8 3 0 0 2
P H O N E : ( 3 0 7 ) 6 9 0 – 4 4 3 6 F A X : ( 3 0 7 ) 7 3 4 – 1 0 2 9
C O L L I N S P L A N N I N G @ O N E W E S T . N E T
1

GENERAL POINTS AND SUGGESTED IDEAS BY STATE AND
SUGGESTED PRINCIPLES TO GUIDE WATER RESOURCE PLANNING
Colorado
1. Two recent legislative acts initiated water planning.
2. 2003 Legislation produced a state-wide supply and demand assessment prepared
by the state.
3. 2005 Legislation produced local basin committees and a statewide committee to
prepare basin-wide assessments and to establish a forum for negotiations and
dispute settlement.
4. Both efforts relied heavily on local basin “round tables” for a bottom-up
approach.
5. The first set of round tables that participated in the state-wide assessment was
selected by the state and contained a uniform level of expertise.
6. The second set of round tables consists of representatives of various stakeholder
groups listed in the legislation and have an uneven level of expertise.
7. The state focuses on providing reliable data and stresses basin level planning by
local “round tables.”
8. The state also administers loan and grant programs for water development
projects.
Nugget: More hand selection of the members of the local committees would produce
more uniform expertise and lead to more productive committees.
Idaho
1. Legislation in 1988 initiated water planning and placed a priority on identifying
and protecting streams with special natural resource value.
2. There is a state-wide water plan consisting of goals/objectives and 39 basin plans.
3. However, only 10 basin plans have been completed in the 18 years since the
program began.
4. These plans are prepared by agency staff. In addition to an insufficient staffing
level, competing demands for the staff time diverts attention away from
completing the basin plans.
5. The basin plans follow a very detailed outline that is established by the state.
6. Local basin committees are formed to participate in the basin planning but the
process is very much driven by the state agency.
7. The state administers several loan and small grant programs.
Nugget: The basin plans identify streams with high natural resource values and
recommends them for protection.
Nugget: The state-wide water plan outlines goals and objectives that guide planning and
decisions.
2

Nugget: The state administers a Water Bank in which water users can temporarily rent
their unneeded water rights to another user, until such time as they need them.
Montana
1. Montana has been struggling for 40 years to find the right planning process.
2. In the 1960’s the state focused on project planning but eventually concluded it
lacked coordination among the various projects and participants.
3. In the 1970’s, they shifted to basin planning but later concluded it lacked political
will for implementation.
4. In 1987, new legislation enacted an elaborate planning process modeled after
Kansas that included numerous committees and a continuous planning program.
5. In the 1990’s, the process shifted again to 50 local committees that focus on
problem solving.
6. The state’s role with these local committees is determined by each committee and
usually is minimal.
7. No uniform structure or scoping – public involvement program exists across the
local groups as each group is responsible for identifying its purpose and
advancing its own initiatives.
Nugget: Place a high value on the need for citizens to see local results from the planning
process.
Kansas
1. Kansas has been involved in water resource planning since 1917 and has become
a model.
2. A state water plan provides general information, addresses several key issues and
contains the 12 basin plans.
3. While this plan is maintained, it and the basin plans are updated as necessary and
the state undertakes numerous studies and reports on a variety of other issues.
4. 1987 legislation revamped the planning process and placed much higher
emphasis on conservation and management of the water resource.
5. Further changes in the last couple of years have focused on establishing priorities
and implementation.
6. Local planning committees were asked to identify their priorities.
7. A sub-cabinet was formed consisting of the heads of seven state agencies that
have water-related responsibilities. The sub-cabinet is responsible for creating
strategic implementation plans to act on the priorities.
Nugget: Setting priorities and establishing implementation plans is the current focus.
Nugget: Coordination is needed among all agencies and organizations, both during
planning and implementation.
Nugget: How the local groups are engaged determines the success or failure of the
planning program. They must see results from their efforts.
3

Texas
1. Texas has been involved in water resource planning since 1961 and also has
become a model. A dozen states have adopted water planning programs modeled
after Texas.
2. Regional water plans are adopted and updated every 5 years. After the
completion of each cycle of regional plans, they are incorporated into a state-wide
water plan that is prepared by the state agency.
3. About 50% of the state water plan is a compilation of regional plans and about
50% of the plan is a discussion of state-wide issues and other topics.
4. Planning regions are established based on basin boundaries, ground water aquifer
locations, population concentrations and development patterns, and other factors.
5. Regional plans are prepared by local committees but follow very detailed
guidelines established by the state agency. The state provides planning funds to
these committees to hire consultants. The state also provides staff support.
6. The state water plan by law must recommend policies to the Legislature.
7. The state administers several loan and grant programs and focuses on a diverse
water portfolio.
Nugget: Establish a standard by which to evaluate the effectiveness of the planning
program. For example, evaluate the planning program by the level of positive
influence it has on implementation and by the improved level of knowledge of
water issues among the Legislature and public.
Nugget: The state cannot finance or fund a project that is not consistent with the regional
plan.
Nugget: The state has a program in which they fund the additional capacity of faculties
that is in excess of a community’s current need, and the community pays back
the funding in the future when the capacity is needed.
Nebraska
1. 2002 legislation initiated water planning in Nebraska and charged a state
committee with evaluating existing laws, inequities among users and transfers.
2. Current efforts focus on identifying basins that are fully or over appropriated.
3. The state is spending significant time and money studying the relationship
between ground and surface water.
4. Wells were permitted for many years with little information or concern about their
cumulative impact. Eventually, the delayed impact the wells had on the water
resource caused significant problems.
5. Local Natural Resource Districts play a central role in evaluating local basins and
implementing plans and regulations that result from the evaluations.
6. Several basins or sub-basins are fully or over appropriated and the state and local
Natural Resource Districts are enforcing plans to reduce water rights or prohibit
any new rights.
4

Nugget: Get all of the physical information on the water resource that can be obtained,
including studying the relationship between ground and surface water.
Utah
1. There is a state-wide water plan that is prepared before the individual basin plans
are prepared. Basin plans are update as needed based on population growth, a
new development project, or some other factor that has caused significant change
in a basin.
2. The state water plan addresses up to 19 various water related issues, in addition
to containing the individual basin plans.
3. The state has adopted the goal of reducing by 25% by 2050 the per capita
municipal and industrial water consumption. They are ahead of schedule.
4. The state is developing a detailed water related land use inventory in which they
will conduct a windshield survey of the entire state within five years.
5. The state also is studying for quality control the water use surveys submitted by
water users, with the goal of developing more detailed understanding of
consumption.
Nugget: Develop ground-verified water related land use mapping and detailed water user
surveys.
Nugget: All water users with more than 500 connections are required to have a state
approved conservation plan.
Nugget: Establish criteria for determining the timing of basin plan updates.
WESTERN STATES SURVEY SUMMARY
The following list of principles summarizes many key points from the Western States
Survey. Many of these principles already are incorporated in the Wyoming Water Basin
Planning Program.
1. Follow Through on Projects. Continue following through on development
projects and planning goals. Maintain a clear process that allows projects and
planning initiatives to be proposed, evaluated and completed.
2. Set Goals and Objectives. The state water plan should establish state-wide goals
and objectives to guide water related decisions.
3. Pursue a Broad Approach. Pursue a broad approach to water resource planning
that includes evaluating the appropriateness of conservation and resource
management techniques in addition to development projects.
4. Create Local Results. Focus on solving problems and addressing issues that are
important to the local residents, which may include referring an issue to another
5

state agency. Place value on citizens seeing local results of water resource
planning.
5. Maintain a Long Term Perspective. While involving local committees and
focusing on their problems can provide tangible local results, some type of
construct is needed to provide focus and priorities. A comprehensive long term
perspective is needed to avoid simply jumping from one individual problem to
another.
6. Remain Flexible. While priorities are important, they must be balanced with
flexibility that allows important issues to be addressed despite them not matching
the priorities. When the focus deviates from the priorities, it occurs deliberately
and in a measured way, thereby maintaining a context.
7. Pursue Meaningful Planning. Avoid preparing basin plans for the sake of
planning. Update these plans as needed but do not become a slave to a standard
cycle of updates when they may not be needed. Instead, include the study and
planning of issues that transcend basin boundaries to ensure all important topics
are covered.
8. Evolve the Planning Process Rather Than Simply Repeat It. Move past the
first stage of planning in which data are collected and issues are identified. A
deeper level of understanding issues comes from preparing responses to them.
Develop strategic plans to follow through on the results of planning, which may
require more detailed information.
9. Coordinate the Players. Coordination and communication among program
personnel is critical and some type of structure is needed to ensure it occurs.
Convene on a regular basis the decision-makers of all agencies that are involved
in water resources.
10. Involve the Local Citizens in Meaningful Ways. Establish balanced and
representative local groups to provide input into water resource planning.
Helping these local groups craft and recommend solutions to local issues sustains
local participation. When the solutions and development strategies come from the
local level, a message is sent to the Legislature that the water planning program is
solving problems and addressing issues.
11. Establish a Report Card. A report card should be prepared on the water
planning program. Perhaps it should focus on two things: the amount of positive
influence brought to bear on issues and problems; and, the level of knowledge and
understanding of water issues among the Legislature and general public.
6

GENERAL CONCLUSIONS AND OBSERVATIONS
Wyoming should feel good about the stage of the state’s water resource planning in the
state. The western states survey reveals that Wyoming is clearly ahead of four of our
neighboring states and at least equal with the fifth. Two additional states, Kansas and
Texas, were included in the survey because they have been used by other states as
models.
Wyoming has solid basin plans completed for all seven major basins that provide a sound
foundation for proceeding. The Framework Plan currently being prepared is both a
conclusion of these basin plans and a new beginning for the next stage of planning.
Before simply launching into updates of these basin plans, we should pause and think
about the focus for the next stage of planning. While Kansas is a national role model,
they also reinvented themselves in recent years, maintaining a high quality of work but
shifting the focus of their attention.
Should we begin updating the basin plans or strike out on a different path in our next
stage of planning? Perhaps we should update basin plans on an as-needed basis and
reserve funds and time for an additional scope of work. Basin plans could be updated
when changes occur that call for a new plan, or they can be supplemented in targeted
ways to fill data gaps. But the wholesale repeat of the basin plans may be unnecessary
until conditions in the basins call for it. This selective approach to updating basin plans
would allow resources to be devoted to studying issues that transcend basin boundaries or
are state-wide concerns. Perhaps we should establish a goal for the next stage of water
resource planning to maintain a set of current basin plans as well as develop data on a
broader array of issues that have state-wide or regional significance.
7

Appendix C
FUTURE BASIN PLAN ORDER

Weighting Factor
3 2 2 3 -2
Completion Date of
Last Basin Plan
Forcasted Population
Increase
Number of BAG Issues
Components of the
Plan That Need
Correcting or Updating
Compact Issues and
Lawsuits
Basin Priority Selection Criteria
Value
7 oldest > 5,000 most most most
6 > 4,000
5 > 3,500
4 > 3,000
3 > 2,000
2 > 1,000
1 newest < 1,000 least least least
Basin
Green 7 5 6 5 4 50
Powder/Tongue 5 4 7 5 7 38
Northeast Wyoming 5 7 2 1 1 34
Wind/Bighorn 2 2 1 7 3 27
Snake/Salt 3 5 3 1 1 26
Bear 6 1 2 1 4 19
Platte 1 7 5 1 7 16
Total
Score
C-1
90% Draft

Green River Basin Population
100000
90000
80000
70000
60000
50000
1995 2000 2005 2010 2015 2020 2025 2030 2035
Year
Low
Mid
High
2000 Census and 2005 Census Bureau Estimate
Platte River Basin Population
450000
400000
350000
300000
250000
200000
1995 2000 2005 2010 2015 2020 2025 2030 2035 2040
Year
Low
Mid
High
2000 Census and 2005 Census Bureau Estimate
Population
Population
Bear River Basin Population
35000
30000
25000
20000
15000
10000
Northeast Wyoming River Basin Population
80000
70000
60000
50000
40000
Population
Population
1995 2000 2005 2010 2015 2020 2025 2030 2035
Year
Low
Mid
High
2000 Census and 2005 Census Bureau Estimate
30000
1995 2000 2005 2010 2015 2020 2025 2030 2035
Year
Low
Mid
High
2000 Census and 2005 Census Bureau Estimate
Basin Planning Study Population Projections and Estimates Provided by Census.
C-2
90% Draft

Snake/Salt River Basin Population
80000
70000
60000
50000
40000
30000
20000
10000
0
1995 2000 2005 2010 2015 2020 2025 2030 2035
Year
Low
Mid
High
2000 Census and 2005 Census Bureau Estimate
Population
Powder/Tongue River Basin Population
55000
50000
45000
40000
35000
30000
25000
20000
1995 2000 2005 2010 2015 2020 2025 2030 2035
Year
Wind/Bighorn River Basin Population
96000
94000
92000
90000
88000
86000
84000
1995 2000 2005 2010 2015 2020 2025 2030 2035
Population
Population
Low
Mid
High
2000 Census and 2005 Census Bureau Estimate
Year
Low
Mid
High
2000 Census and 2005 Census Bureau Estimate
Basin Planning Study Population Projections and Estimates Provided by Census.
C-3
90% Draft

Appendix D
PUBLIC COMMENTS

Public Comments on the Wyoming Framework Water Plan 90%
Comment Author Action Taken
Praise Jack E Clusses No action was required.
Climate change addition Steve Gray A new paragraph was added.
Enlarging scope of Volume II John Joyce A recommendation was included in Volume II.
Request for groundwater plan in the Platte Basin Liberty Blain A recommendation was included in Volume II.
Shoshone Irrigation Project details
Klodette Stroh
None required, this level of detail wasn't presented for any of
the irrigation projects in the state.
Angler Days
George Simonton A recommendation was included in Volume II.
D-1

D-2

D-3

D-4

D-5

D-6

D-7

D-8

D-9

D-10

D-11