U.S. Department of the Interior

U.S. Geological Survey

Fact Sheet 2007–3029

May 2007

GROUND-WATER RESOURCES PROGRAM

Changes in Water Levels and Storage in the High Plains 

Aquifer, Predevelopment to 2005

—By V.L. McGuire

Printed on recycled paper

The High Plains aquifer underlies 

111.4 million acres (174,000 square 

miles) in parts of eight States—Colorado, Kansas, Nebraska, New Mexico, 

Oklahoma, South Dakota, Texas, and 

Wyoming. The area overlying the 

High Plains aquifer is one of the major 

agricultural regions in the world. Waterlevel declines began in parts of the High 

Plains aquifer soon after the beginning 

of extensive ground-water irrigation. By 

1980, water levels in the High Plains 

aquifer in parts of Texas, Oklahoma, 

and southwestern Kansas had declined 

more than 100 feet (Luckey and others, 

1981). In response to these water-level 

declines, the U.S. Geological Survey 

(USGS), in cooperation with numerous Federal, State, and local waterresources agencies, began monitoring 

more than 7,000 wells in 1988 to 

assess annual water-level change in 

the aquifer. A report by the USGS, 

“Water-Level Changes in the High 

Plains Aquifer, Predevelopment to 

2005 and 2003 to 2005” (McGuire, 

2007), shows the areas of substantial 

water-level changes in the aquifer 

from the time prior to substantial 

ground-water irrigation development 

(predevelopment or about 1950) to 

2005 (fig. 1).

In parts of the area, farmers 

began using ground water for irrigation extensively in the 1930s and 

1940s. Estimated irrigated acreage 

in the area overlying the High Plains 

aquifer increased rapidly from 1940 

to 1980 and changed slightly from 

1980 to 2002: 1949—2.1 million 

acres, 1980—13.7 million acres, 

1997—13.9 million acres, 2002—

12.7 million acres. Irrigated acres 

in 2002 were 12 percent of the 

aquifer area, not including the areas 

with little or no saturated thickness 

(McGuire, 2007). 

Figure 1. Water-level changes in the High Plains aquifer, predevelopment to 2005 (modified from 

McGuire, 2007).

U

U

U

U

U

U

U

NEW MEXICO

COLORADO

TEXAS

KANSAS

NEBRASKA

WYOMING SOUTH DAKOTA

OKLAHOMA

HIGH

PLAINS

AQUIFER

BOUNDARY

32°

33°

34°

35°

36°

37°

38°

39°

40°

41°

42°

43°

106° 105° 104° 103° 102° 101° 100° 99° 98° 97° 96°

Base from U.S. Geological Survey digital data, 1:2,000,000

Albers Equal-Area projection, Horizontal datum NAD 83,

Standard parallels 29°30’ and 45°30’, central meridian -101°

EXPLANATION

Water-level change, in feet

Declines

No substantial change

Rises

Area of little or no 

saturated thickness

Faults—U, upthrown side

County boundary

More than 150

100 to 150

50 to 100

25 to 50

10 to 25

10 to 25

25 to 50

More than 50

-10 to +10

U
Ground-water withdrawals for irrigation and other uses 

are compiled and reported by the USGS and agencies in each 

State about every 5 years. Ground-water withdrawals from the 

High Plains aquifer for irrigation increased from 4 to 19 million acre-feet from 1949 to 1974. Ground-water withdrawals 

for irrigation in 1980, 1985, 1990, and 1995 were from 4 to 

18 percent less than withdrawals for irrigation in 1974. 

Ground-water withdrawals from the aquifer for irrigation in 

2000 were 21 million acre-feet (McGuire, 2007). 

Water-level changes in the aquifer result from an imbalance between discharge and recharge. Discharge is primarily ground-water withdrawals for irrigation. Discharge also 

includes evapotranspiration, where the water table is near the 

land surface, and seepage to streams and springs, where the 

water table intersects with the land surface. Recharge is primarily from precipitation. Other sources of recharge are irrigation 

return flow and seepage from streams, canals, and reservoirs. 

Water-level declines may result in increased costs for groundwater withdrawals because of increased pumping lift and 

decreased well yields (Taylor and Alley, 2001). Water-level 

declines also can affect ground-water availability, surface-water 

flow, and near-stream (riparian) habitat areas (Alley and others, 

1999).

Water-Level Changes, 

Predevelopment to 2005

The map of water-level changes in the High Plains aquifer 

from predevelopment to 2005 (fig. 1) was generated using 

methods described by McGuire (2007). The map is based on 

water levels from 3,682 wells, which were measured in predevelopment and in 2005, and other previously published data 

in areas with few predevelopment water levels. The areas with 

few predevelopment water levels are in the central part of the 

Nebraska Panhandle, west-central Nebraska, and southeastern 

Wyoming. 

The water-level changes from predevelopment to 2005 

ranged between a rise of 84 feet and a decline of 277 feet. 

Area-weighted, average water-level change from predevelopment to 2005 was a decline of 12.8 feet. Approximately 

25 percent of the aquifer area had more than 10 feet of waterlevel decline from predevelopment to 2005; 17 percent had 

more than 25 feet of water-level decline, and 9 percent had 

more than 50 feet of water-level decline. Approximately 

2 percent of the aquifer area had more than 10 feet of waterlevel rise from predevelopment to 2005 (McGuire, 2007).

Change in Water in Storage, 

Predevelopment to 2005

Total water in storage in 2005 was about 2,925 million 

acre-feet, which was a decline of about 253 million acre-feet 

(or 9 percent) since predevelopment. Water in storage for 

predevelopment was inferred from water in storage in 2000 and 

water-level changes from predevelopment to 2000. Changes in 

storage prior to predevelopment were not estimated (McGuire, 

2007).

References Cited

Alley, W.M., Reilly, T.E., and Franke, O.L., 1999, Sustainability of ground-water resources: U.S. Geological Survey 

Circular 1186, 78 p., accessed March 22, 2007, at http://

pubs.usgs.gov/circ/circ1186/

Luckey, R.R., Gutentag, E.D., and Weeks, J.B., 1981, Waterlevel and saturated-thickness changes, predevelopment 

to 1980, in the High Plains aquifer in parts of Colorado, 

Kansas, Nebraska, New Mexico, Oklahoma, South Dakota, 

Texas, and Wyoming: U.S. Geological Survey Hydrologic 

Investigations Atlas HA–652, 2 sheets, scale 1:2,500,000, 

accessed March 22, 2007, at http://pubs.er.usgs.gov/

usgspubs/ha/ha652

McGuire, V.L., 2007, Water-level changes in the High 

Plains aquifer, predevelopment to 2005 and 2003 to 2005: 

U.S. Geological Survey Scientific Investigations Report 

2006–5324, 7 p., accessed March 22, 2007, at http://pubs.

usgs.gov/sir/2006/5324/

Taylor, C.J., and Alley, W.M., 2001, Ground-water-level 

monitoring and the importance of long-term waterlevel data: U.S. Geological Survey Circular 1217, 68 p., 

accessed March 22, 2007, at http://pubs.usgs.gov/circ/

circ1217/

Acknowledgments

The water-level data used in this report were provided 

by the following agencies—Colorado: State Engineer’s 

Office; Kansas: Department of Agriculture—Division of 

Water Resources and Kansas Geological Survey; Nebraska: 

Central Nebraska Public Power and Irrigation District, Natural Resources Districts, and University of Nebraska—Lincoln, Conservation and Survey Division; New Mexico: Office 

of the State Engineer; Oklahoma: Water Resources Board; 

South Dakota: Department of Environment and Natural 

Resources; Texas: Water Development Board and Groundwater Conservation Districts; Wyoming: State Engineer’s 

Office; and Federal: Bureau of Reclamation, U.S. Fish and 

Wildlife Service, and U.S. Geological Survey offices in 

Colorado, Kansas, Nebraska, New Mexico, Oklahoma, South 

Dakota, Texas, and Wyoming.

For More Information

Contact: Director

 USGS Nebraska Water Science Center

 5231 South 19th Street

 Lincoln, NE 68512 

 (402) 328–4100 Copies of this fact sheet may be obtained from: 

U.S. Geological Survey, Information Services, 

Box 25286, Denver Federal Center, Denver, CO 80225.