US Geological Survey



Date of this Version



U.S. Department of the Interior, U.S. Geological Survey, Fact Sheet 2019–3055, March 2020

ISSN 2327-6916 (print)

ISSN 2327-6932 (online)


Groundwater provides nearly 50 percent of the Nation’s drinking water. To help protect this vital resource, the U.S. Geological Survey (USGS) National Water-Quality Assessment (NAWQA) Project assesses groundwater quality in aquifers that are important sources of drinking water. The High Plains aquifer constitutes one of the important aquifers being evaluated.

The High Plains aquifer underlies an area of about 169,000 square miles, which is populated by about 2 million people in parts of eight western states (Colorado, Kansas, Nebraska, New Mexico, Oklahoma, Texas, South Dakota, and Wyoming). The aquifer ranks 13th in the Nation as a source of groundwater for public supply, with about 390 million gallons per day pumped for this use in 2000 (Maupin and Barber, 2005; Arnold and others, 2020a). The aquifer is also extensively used for agriculture, ranking first in the Nation as a source of groundwater for irrigation, with water pumped for irrigation markedly higher than for public supply (17,000 million gallons per day). Land use overlying the High Plains aquifer is composed primarily of natural land cover (including rangeland; 59 percent) and agricultural land (37 percent) with relatively small areas of urban and other developed land (4 percent; Homer and others, 2015). About 20 percent of the Nation’s irrigated agricultural land overlies the High Plains aquifer. The four largest cities that lie within the aquifer’s overlying land are Amarillo, Lubbock, and Midland, Texas, and Cheyenne, Wyoming. Most of the population of the region reside in smaller cities and towns and rural areas. Urban development is much less widespread than agriculture over the High Plains aquifer.