Over 4,500 wells have been drilled as part of the test hole program. 1,178,786 Thickness of the Principal Aquifer A series of contour lines showing the estimated thickness of the saturated sediments that serve as the source aquifer for domestic and irrigation wells. It was digitized from eleven 1980 USGS 1x2 degree quadrangles and has been used as the 'normal' thickness of the aquifer. All cities and towns in the state. Data includes 590 towns and villages, population in 1980 and 1990, hospital, and county seat.
Unincorporated towns have zero population.
Mapping and automating status fields are included, but are mostly blank. This cover is the tic-base for digitizing quadrangle maps. Over 1,300 tics are present, coded by row-column. Used to determine the number of acres of each vegetation type across Nebraska. This file was interpreted by USGS water scientists to show areas of rise and decline of the ground water table in 1994.