Water-Level Changes in the High Plains Aquifer--Predevelopment to 1992

By Jack T. Dugan, Timothy McGrath, and Ronald B. Zelt

U.S. Geological Survey
Water-Resources Investigations Report 94-4027
Lincoln, Nebraska
1994

Abstract:

Since 1980, water levels in those areas of large declines in the Central and Southern High Plains have continued to decline, but at a much slower annual rate. The estimated average area-weighted water-level decline from 1980 to 1992 for the entire High Plains was 2.24 feet, which is an average annual decline of about 0.19 foot. The slower rate of decline since 1980, in relation to the rates prior to 1980, is associated with a decrease in ground-water application for irrigated agriculture and greater than normal precipitation. Water-conserving practices and technology, in addition to reductions in irrigated acreages, contributed to the decrease in ground-water withdrawals for irrigation.

Water-level declines exceeding 20 feet since 1980, however, are widespread in parts of southwestern Kansas, east-central New Mexico, and the Oklahoma and Texas Panhandles. Widespread declines of 10 to 20 feet and exceeding 20 feet in smaller areas occurred in northeastern Colorado, northwestern Kansas, southwestern Nebraska, and the Nebraska Panhandle from 1980 to 1992. Water-level rises exceeding 20 feet occurred in the extreme Southern High Plains in Texas where precipitation was much greater than normal from 1980 to 1992. Widespread water-level rises of 5 to 10 feet occurred in eastern Nebraska during the same period in association with greater than normal precipitation.

The estimated average area-weighted water-level decline from 1991 to 1992 was 0.55 foot, even though precipitation was well-above normal in 1991 in the High Plains (+1.98 inches). Water-level declines of 3 to 5 feet were widespread in the intensively irrigated areas of the Central and Southern High Plains, particularly southwestern Kansas and the High Plains of Texas. These declines do not appear to be closely related to the 1991 precipitation patterns in these areas. Declines of 1 to 3 feet were common throughout the intensively irrigated areas of the Northern High Plains and the less intensively irrigated areas of the Central and Southern High Plains. Water levels continued to rise, generally 1 to 3 feet, in the extreme southeastern part of the Southern High Plains in Texas. Widely scattered areas of 1- to 3-foot rises also occurred in parts of northeastern and central Nebraska where precipitation was near to slightly greater than normal in 1991.

          Kathy Wilson
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