Geologic And Hydrologic Factors Governing ... - Gunnison County

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Geologic And Hydrologic Factors Governing Impacts Of Development On The Crystal River Near Marble, Colorado Gunnison County, Colorado The faults and joints can provide a source of groundwater. Most of the faults are stable and there will be no movement along the faults unless a fault block on the downslope side is undercut during the course of development. On the east side of Carbonate Creek fault blocks in bedrock have been undercut by the erosion of Carbonate Creek. These fault blocks probably will move with time and continued erosion of Carbonate Creek. Buildings should not be founded on bedrock across faults because there could be differential compaction of the bedrock on either side of the fault as the rock adjacent to the faults is typically more highly jointed or fractured. Joints would be capable of trans- porting limited quantities of leaching field effluent. 4.4 Soil Permeability Permeability is one of several factors limiting the suitability of soil for septic tank use. Other factors include slope, water table, groundwater return flow paths, domestic well locations, etc. Soil permeability also provides a major control for infiltration and groundwater recharge. Drawing 8 does not consider any factor other than permeability as a limitation to the use of septic tanks or groundwater recharge. Any subsequent map will use some different soil series names which may alter some of the USFS interpretations. The Natural Resources Conservation Services (NRCS), formerly the Soil Conservation Service, has not yet correlated the mapping units to soil series in Colorado. Since the NRCS has additional information on septic tank soil suitability and permeability, some of the limitations may change. The reference map uses “stop light” colors with: • Red indicating severe limitation of infiltration or leaching field use due to permeability rat- ings greater than 101 minutes per inch. • Yellow indicating moderate limitation due to permeability rating between 100 and 61 minutes per inch. • Green indicating slight limitation due to permeability rating equal to or less than 60 minutes per inch. 951-110.000 Wright Water Engineers, Inc. Page 31
Geologic And Hydrologic Factors Governing Impacts Of Development On The Crystal River Near Marble, Colorado Gunnison County, Colorado These interpretations are generalized by mapping unit for planning purposes. Any unit may contain inclusions of other soils, which may have different limitations. Septic tank placement always re- quires an on-site investigation. The following briefly describes the characteristics of the soil within each area: AREA 104A Permeability Limitations: Slight to severe because: Major soil type (65% Cryoborolls) has variable permeability from high to low. The 104A soils are situated in areas subject to flooding and high water table. Conclusion: Slight to severe limitation. Wide range of permeability AREA 203B Permeability Limitations: Slight in major soil type (60% Handran), which has a permeability of 15 minutes per inch. Slight in second major soil type (30% Gateview) which has a permeability of 46 minutes per inch. Conclusion: Slight limitation due to permeability. 6 to 60 minutes per inch—90% AREA 210D Permeability Limitations: Slight in major soil type (60% Cryoborolls), which has a permeability of 18 minutes per inch. Severe in second major soil type (25% Rock Outcrop), which has permeability rates greater than100 minutes per inch. Conclusion: Slight to severe based on permeability. 6 to 60 minutes per inch—60% 101 to 500 minutes per inch—25% AREA 212C Permeability Limitations: Slight in major soil type (90% Scout), which has a permeability of 15 minutes per inch. Conclusion: Slight limitations based on permeability. 6 to 60 minutes per inch—90% AREA 281B Permeability Limitations: Generally high permeability, but site-specific as to permeability. Conclusion: High permeability. Partially in excess of 5 minutes per inch 951-110.000 Wright Water Engineers, Inc. Page 32
Page 1 and 2: GEOLOGIC AND HYDROLOGIC FACTORS GOV
Page 3 and 4: TABLE OF CONTENTS Page 1.0 INTRODUC
Page 5 and 6: LIST OF FIGURES FIGURE 1 REDSTONE A
Page 7 and 8: Geologic And Hydrologic Factors Gov
Page 19 and 20: 3.2.1 Landslides Geologic And Hydro
Page 25 and 26: Jan Feb 4 2 3.4 Mar 3.5 Apr 2.4 1.8
Page 31 and 32: Annual Sediment Yield (S) (acre-fee
Page 33 and 34: 4.3.3 Alluvial Deposits Geologic An
Page 35: 4.3.8 Faults and Joints Geologic An
Page 71 and 72: 8.0 REFERENCES Geologic And Hydrolo
Page 73: APPENDIX A THE MARBLE AREA A DEVELO
Page 89 and 90:
PERMIT NO. NAME RNG TWN PERMITTED W
Page 91:
APPENDIX C TABULATION OF WATER QUAL
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Geologic And Hydrologic Factors Governing ... - Gunnison County

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