U.S. Department of the Interior—U.S. Geological Survey

Water-Level Changes in the High Plains

Aquifer, 1980 to 1994

Figure 1. Water-level change in the High Plains aquifer, 1980 to 1994.

The High Plains aquifer underlies

one of the major agricultural areas

in the world in parts of Colorado,

Kansas, Nebraska, New Mexico,

Oklahoma, South Dakota, Texas,

and Wyoming. Nearly 30 percent

of the ground water used for irrigation in the United States is pumped

from the High Plains aquifer

(Weeks and others, 1988). In

1990, 15.6 million acre-feet of

water was withdrawn from the

aquifer to irrigate approximately

14 million acres (Carr and others,

1990).

Water-level declines appeared in

the High Plains aquifer soon after

extensive ground-water irrigation

development first began in about

1940. By 1980, water levels in

parts of the Texas High Plains,

Oklahoma Panhandle, and

southwestern Kansas declined

more than 100 feet. In response

to these declines, the U.S.

Geological Survey (USGS)

began an ongoing groundwater monitoring program in

1988 to annually assess waterlevel change in the aquifer.

Numerous Federal, State, and

local water-resource agencies,

in cooperation with the USGS,

currently measure water levels

in more than 8,000 wells

annually in the High Plains.

WATER-LEVEL

CHANGE, 1980 TO

1994

The geographic patterns of

water-level change in the

High Plains from 1980 to

1994 largely replicate the

patterns of change from

predevelopment to 1980.

Large water-level declines

have continued in parts of

the Texas High Plains,

Oklahoma Panhandle,

and southwestern Kansas

(fig. 1). Some areas of

substantial decline

prior to 1980 in the

RIVER

More than 40

20 to 40

10 to 20

5 to 10

No Significant Change

-5 to 5

Rises

5 to 10

10 to 20

20 to 40

More than 40

Area of little or no

 saturated thickness

Water-level change,

in feet, 1980 to 1994

EXPLANATION

HIGH

PLAINS

AQUIFER

BOUNDARY

Declines

NEBRASKA

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

32°

33°

34°

35°

36°

37°

38°

39°

40°

41°

42°

43°

WYOMING SOUTH DAKOTA

COLORADO KANSAS

NEW MEXICO

OKLAHOMA

TEXAS

River

R EPUBLICAN

Platt e

South

RIVER

ARKANSAS

RIVER

RIVER

CANADIAN

North Platte River

PLATTE

0 100 MILES

0 100 KILOMETERS
Northern High Plains, however, have generally had either water-level rises or considerably slower rates of decline since 1980.

The water-level rises in parts of the eastern

High Plains of Nebraska and the extreme

southern High Plains of Texas are closely

associated with well above normal precipitation in these areas since 1980.

The area-weighted average water level in

the High Plains (table 1) declined 1.54 feet

from 1980 to 1994—about 0.11 foot annually. This compares to 9.90 feet from

predevelopment (1940) to 1980—about

0.25 foot annually. The slower rate of decline

since 1980 can be largely attributed to the

average water-level rise of 1.88 feet

(0.13 foot annually) in Nebraska. The

average annual rate of decline in Texas

decreased from 0.84 foot, from predevelopment to 1980, to 0.22 foot, from 1980 to

1994. Only in Kansas has the average

annual rate of decline been more rapid since

1980—0.33 foot prior to 1980 and 0.44 foot

since 1980. The slower rate of decline after

1980 occurred even though the 1980-to-1994

average annual irrigated acreage was more

than double (14 million acres) the predevelopment-to-1980 average annual irrigated

acreage (6 million acres). The following

factors appear to have contributed to the

much slower rate of water-level decline in

the High Plains after 1980:

• Precipitation from 1980 to 1994 was generally well above normal throughout the

High Plains. Average annual precipitation during 1981–93 was 21.18 inches

or 1.40 inches above normal.

• Later phases of irrigation development in

the High Plains shifted geographically

from areas of more rapid potential rates

of aquifer depletion (Central and Southern High Plains) to areas of slower

potential rates of depletion (Northern

High Plains).

• Significant advances in irrigation technology, such as center-pivot irrigation and

gated pipe, have substantially reduced

the ground-water pumpage needed to

meet consumptive irrigation requirements.

• Irrigation management practices, including irrigation scheduling and the

conversion to crops or varieties with

smaller consumptive irrigation requirements, have further reduced groundwater pumpage.

• Water-level declines in some areas prior to

1980 prompted local regulation of

ground-water withdrawals for irrigation

and development of irrigated land.

• Economic considerations, including

lower crop prices and higher production

costs (such as rising energy prices),

have forced marginal land out of

irrigated production.

WATER-LEVEL CHANGE,

1993 TO 1994

The area-weighted average water level

from 1993 to 1994 rose in the High Plains for

a second consecutive year. The 0.56-foot rise

from 1993 to 1994 (table 2) was considerably

larger than the average rise of 0.21 foot from

1992 to 1993 (Dugan and Cox, 1994). The

larger rise may be attributed to precipitation

in the High Plains that averaged 4.24 inches

above normal in 1993, as compared to

2.03 inches above normal in 1992. The

larger rise from 1993 to 1994 also may be

associated with the accumulative effect of

3 consecutive years of above-normal precipitation in the High Plains. The area-weighted

average precipitation in the High Plains

during 1990–93 was 2.49 inches above

normal.

Although the area-weighted average

water level rose in the High Plains from

1993 to 1994 and the area-weighted average

precipitation was well above normal in 1993,

these conditions were not uniform across the

High Plains (tables 2 and 3). Both waterlevel change and precipitation presented

strongly contrasting regional patterns within

Table 1. Average area-weighted waterlevel change in the High Plains aquifer,

1980 to 1994

State

Area-weighted waterlevel change (feet)

Predevelopment

to 1980

1980 to

1994

Colorado -4.20 -3.39

Kansas -9.90 -6.12

Nebraska 0 +1.88

New Mexico -9.80 -2.31

Oklahoma -11.30 -1.81

South Dakota 0 +1.47

Texas -33.7 -3.02

Wyoming 0 -2.52

High Plains -9.90 -1.54

the High Plains (fig. 2). Declines exceeding

3 feet extended in a nearly continuous

100-mile arc from eastern New Mexico

across the northern part of the Southern High

Plains of Texas. The area-weighted average

water-level decline was nearly 1 foot in the

High Plains of Texas and 0.27 foot in New

Mexico (table 2). Precipitation was generally

below normal in 1993 in those parts of the

Southern and Central High Plains with widespread water-level declines from 1993 to

1994 (table 3).

Table 2. Average area-weighted waterlevel change from 1993 to 1994

State

Area-weighted

water-level

change (feet)

Colorado -0.13

Kansas +.55

Nebraska +1.81

New Mexico -.27

Oklahoma +.10

South Dakota +.38

Texas -.99

Wyoming +.13

High Plains +0.56

Table 3. Average area-weighted precipitation in the High Plains in 1993, departure

from 30-year normal (1961–90), and

percentage of normal

State

Average

areaweighted

precipitation

(inches)

Average

areaweighted

departure

from

30-year

normal

(inches)

Percentage of

normal

Colorado 17.42 +1.14 107

Kansas 28.75 +7.26 134

Nebraska 29.38 +7.87 137

New

Mexico

15.10 -1.28 92

Oklahoma 19.44 -.25 99

South

Dakota

25.69 +6.98 137

Texas 17.56 -1.37 93

Wyoming 18.01 +3.67 126

High

Plains

24.02 +4.24 121
In contrast, water-level rises of at least 1 to

3 feet were widespread throughout much of

the Northern High Plains and northeastern

half of the Central High Plains from 1993 to

1994. The average area-weighted water level

rose 1.81 feet in the Nebraska High Plains

and 0.55 foot in the Kansas High Plains

(table 2). The widespread water-level rises

throughout the Northern High Plains and

parts of the Central High Plains from 1993 to

1994 were associated with one of the wettest

years on record in those areas. The areaFigure 2. Water-level change in the High Plains aquifer, 1993 to 1994.

More than 5

3 to 5

1 to 3

No Significant Change

Declines

-1 to 1

Rises

1 to 3

3 to 5

More than 5

Area of little or no

 saturated thickness

Water-level change,

in feet, 1993 to 1994

EXPLANATION

HIGH

PLAINS

AQUIFER

BOUNDARY

NEBRASKA

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

32°

33°

34°

35°

36°

37°

38°

39°

40°

41°

42°

43°

WYOMING SOUTH DAKOTA

COLORADO KANSAS

NEW MEXICO

OKLAHOMA

TEXAS

River

R EPUBLICAN

Platt e

South

RIVER

ARKANSAS

RIVER

RIVER

CANADIAN

North Platte River

PLATTE

0 100 MILES

0 100 KILOMETERS
weighted average precipitation in the High

Plains of Kansas, Nebraska, and South

Dakota was about 7 inches or more above

normal in 1993 (table 3). Normal precipitation was exceeded by 10 inches or more over

large parts of eastern and south-central

Nebraska where water-level rises exceeding

5 feet were widespread.

—Jack T. Dugan and

Jennifer B. Sharpe

REFERENCES

Carr, J.E., Chase, E.B., Paulson, R.W., and

Moody, D.W., 1990, National water

summary 1987—Hydrologic events and

water supply and use: U.S. Geological

Survey Water-Supply Paper 2350,

552 p.

Dugan, J.T., and Cox, D.A., 1994, Water-level

changes in the High Plains aquifer—Predevelopment to 1993: U.S. Geological

Survey Water-Resources Investigations

Report 94–4157, 60 p.

Weeks, J.B., Gutentag, E.D., Heimes, F.J., and

Luckey, R.R., 1988, Summary of the High

Plains regional aquifer-system analysis in

parts of Colorado, Kansas, Nebraska, New

Mexico, Oklahoma, South Dakota, Texas,

and Wyoming: U.S. Geological Survey

Professional Paper 1400–A, 30 p.

FOR MORE INFORMATION

For more information, please contact

District Chief

U.S. Geological Survey

406 Federal Building

100 Centennial Mall North

Lincoln, NE 68508

(402) 437–5082

November 1995 Fact Sheet FS–215–95