Ground water is the principal source of water for public and self-supplied domestic use in Nebraska. Ground water supplied about 235 Mgal/d (million gallons per day) in 1990, or about 78 percent of the estimated public-water supply in Nebraska. In addition, ground water supplied about 1,017 Mgal/d, or about 83 percent of the irrigation water in the Platte River Valley (Nebraska Natural Resources Commission, 1994). Withdrawing ground water in the valley induces recharge from the river and has the potential to change ground-water quality near the river where many public-supply wells are located.
The Platte River alluvial aquifer, which underlies the Platte River Valley (fig. 1), is the single most important source of water for public supply in central and eastern Nebraska. The aquifer, which is part of the High Plains aquifer, consists of stream-laid deposits of sand and gravel with discontinuous layers of clay and silt, and is connected hydraulically to the Platte River. The aquifer provides about 117 Mgal/d, or nearly 50 percent of the total daily ground-water production for Nebraska (Nebraska Natural Resources Commission, 1994). The aquifer also supplies water to Nebraska's largest cities including Kearney, Grand Island, Lincoln, and Omaha.