Perspectives on the Nation's Ground- Water Availability

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Perspectives on the Nation's Ground- Water Availability

ong>Perspectivesong> on the Nation’s Ground-

Water Availability

William M. Alley

Sioux Falls

October 30, 2007


Principal Aquifers of the United States

Source: Ground Water Atlas of the United States

http://capp.water.usgs.gov/gwa/


20 aquifers account for 90% of total

aquifer withdrawals

(Maupin and Barber, 2005)


Long-term interest in ground-water monitoring

“The program should cover the water-bearing formations in all sections of

the country; it should include beds with water-table conditions, deep

artesian aquifers, and intermediate sources....This nationwide program

should furnish a reliable basis for periodic inventories of the ground-water

resources, in order that adequate provision may be made for our future

water supplies.”

O.E. Meinzer, 1935


Ground-Water Reservoirs with Perennial

Overdraft (Thomas, 1951)


Significant Cones of Depression

(Thomas, 1951)


Water-Table or Artesian Water-Level Decline

> 40 feet

Source: 1983 National Water Summary


Artesian Well

Woonsocket, SD

Circa 1900


Artesian Well

Lancaster, CA

Circa 1920


Ground-Water Sustainability

Source: DOI, Upper San Pedro Partnership


The Myth of Recoverable Ground Water in

Storage

Top of aquifer

Volume of aquifer

Bottom of

aquifer

Recoverable Ground Water =

(Volume of aquifer) X (Specific yield)


Depletion of a small part of the total volume of water in

storage can have large effects on surface water, water

quality, and subsidence which become limiting factors to

development.

Houston, TX

Upper San Pedro Basin,

AZ

Republican River Basin,

CO, KS, NE

Edwards Aquifer, TX


Land surface

Water table

Stream

Height of water table

above stream bottom

Ground-water system

Thickness

below

stream

bottom


GW and SW: A single resource

“Tonight I’m calling on Democrats and Republicans to pass

legislation to protect our groundwater against withdrawals that

significantly damage our rivers, lakes, wetlands, and springs.”

Governor James Doyle, 2004

Wisconsin State of the State address.


The time period and locations over which capture occurs

depends on aquifer shape, hydraulic properties, and

proximity of pumping to recharge and discharge features.

Fillippone

and Leake,

2005


Example of Simulated Streamflow Capture

Leake, Hoffmann, and Dickinson, 2005


Water Availability & Water Quality

• Contamination from land surface

• Cross contamination in wells

• Contamination by surface water

• Naturally-occurring substances

• Saltwater intrusion

• Artificial recharge


Antelope Valley Subsidence

Source: Galloway and others, 2003


Water Availability & Climatic Change

Less snow/more rain

Knowles et al., 2006

Less spring snowpack

Mote, 2003

TRENDS (1950-97) in

April 1 snow-water content at

western snow courses

-2.2 std devs

LESS as snowfall

+1 std dev

MORE as snowfall

Mote, 2003

Spring snowmelt-onset dates

Earlier snowmelt runoff

Stewart et al., 2005


Importance of Long-Term Data


Predevelopment water-level observations are needed to

estimate ground-water depletion


Without consistently measured water levels, intermediate information on

the ground-water system is incomplete.

0

50

Site ID: 330107112000501

Well Name: D-05-03 01DAD1

Longitude: -111.995833

Latitude: 33.01861111

Altitude of Land Surface: 1212 [ft AMSL]

Well Depth: 404 [ft]

USGS data

ADWR* data

0

50

Site ID: 330147112005001

Well Name: D-04-03 35DDD

Longitude: -112.013055

Latitude: 33.02888888

Altitude of Land Surface: 1200 [ft AMSL]

Well Depth: 385 [ft]

USGS data

ADWR* data

Depth to Ground Water Below LSD [feet]

100

150

200

250

300

350

400

450

500

Depth to Ground Water Below LSD [feet]

100

150

200

250

300

350

400

450

500

550

550

600

Dec-26 Dec-31 Dec-36 Dec-41 Dec-46 Dec-51 Dec-56 Dec-61 Dec-66 Dec-71 Dec-76 Dec-81 Dec-86 Dec-91 Dec-96 Dec-01 Dec-06

Date of Measurement

600

Dec-26 Dec-31 Dec-36 Dec-41 Dec-46 Dec-51 Dec-56 Dec-61 Dec-66 Dec-71 Dec-76 Dec-81 Dec-86 Dec-91 Dec-96 Dec-01 Dec-06

Date of Measurement

This well does not provide a clear

picture of ground-water conditions

in the 35 years between observations.

A nearby well was measured more

consistently.


Consistent and

frequent

observations

allow

identification of

recent trends,

even if

comparison to

predevelopment

water levels is

not possible.

Tillman and Leake, in press


Microgravity

Pool and others, 2000


http://www.csr.utexas.edu/grace/


Ground-Water Response to Pumping


Each ground-water system is unique in its

response to pumping

Alley and others, 2002; Data from Johnston, 1997


Examples

• High Plains aquifer

• Middle Rio Grande Basin

• San Bernardino area, CA


High Plains Aquifer

WATER IN STORAGE IN THE HIGH PLAINS AQUIFER,

PREDEVELOPMENT AND 2001

2,000 Predevelopment

2001

1,500

1,000

500

Colorado

Kansas

Nebraska

New Mexico

Oklahoma

South Dakota

Texas

Wyoming

0

Data from McGuire and others, 2003

Water in storage, Million acre-feet


High Plains Aquifer—Bathtub or Egg

Carton?

Alley and Schefter, 1987


Rio Puerco

Cochiti

Lake

Rio Grande

Albuquerque

Santa

Fe

Middle Rio

Grande Basin

Study Area:

between Cochiti

and San Acacia –

about 3,000 mi 2

Rio Salado

San

Acacia

Mullins and Hare (1999)


Need for Better Understanding of Geologic

Framework

With limited information in the 1960’s With more information in the 1990’s

Modified from Bjorklund and Maxwell (1961) Modified from Hawley (1995)


Need for Better Understanding of Recharge

and SW/GW Interactions

•Aquifer recharge less and

distributed differently than

assumed

•Improved understanding of

river depletion in response to

pumping (less hydraulic

connection in some areas)

(Plummer, et al., 2004)


Simulated Annual Water Budget

Source: McAda and Barroll, 2002


Subcommittee on

Ground Water

Bob Schreiber, ACWI – ASCE

Bill Cunningham, USGS

Executive Secretary

Chris Reimer, NGWA

Monitoring

Inventory

Work Group

Bill Cunningham, USGS

Mike Wireman, USEPA

Emery Cleaves, AASG

Data Standards

and Data

Management

Work Group

Chuck Job, USEPA

Field

Practices

Work Group

Rod Sheets, USGS

Mike Nickolaus, GWPC

Monitoring

Network

Work Group

Bob Schreiber,

ACWI- ASCE

Quantity

Quality

Quantity

Quality


Integrated Monitoring and Modeling

Monitoring (Water Levels, Water Quality, Streamflow, Water Use)

Initial

Model

Adjust

monitoring

network

Update

Conceptual

Model

Adjust

monitoring

network

Simulation

Model

Update

Conceptual

Model

Adjust

monitoring

network

Simulation

Model

Environmental Tracer Data

Geologic and Hydrologic

Studies

Environmental Tracer Data

Geologic and Hydrologic

Studies

Alley, 2006


USGS Ground-Water Resources Program

Regional Water Availability Studies


Products

Water budgets of major aquifer systems

• Current estimates and historic trends in ground-water

storage, recharge, and discharge

Ground-water models that provide

– Regional context for more local studies

– Tool for future projections of water availability

• Estimates of key hydrologic variables across major

regional aquifers

• Evaluation of existing monitoring network

• Testing and evaluation of new approaches for

analysis of regional aquifers


In Summary…

• Some ability to track ground-water conditions for

many aquifers in U.S

• Much more limited ability to place data in context of

ground-water sustainability (a societal concept)

• Dynamic response to stress and associated issues of

concern vary among regional aquifer systems

• Need integrated approach with feedback among

monitoring, simulation, scientific studies, and

management approaches

• A full national picture would require synthesis of

investigations at multiple scales done by many

agencies

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