Locations, values, and uncertainties of hydraulic-head observations for the steady-state, prepumped period of the transient ground-water flow model, Death Valley regional ground-water flow system, Nevada and California

This digital geospatial data set contains the locations, values, and uncertainties of 700 hydraulic-head observations used in the steady-state, prepumped period of the transient model of the Death Valley regional ground-water flow system (DVRFS), a 100,000-square-kilometer region of southern Nevada and California. Hydraulic-head observations, which are the composite of one or more water-level measurements made at a well, are used to calibrate ground-water flow models. To develop hydraulic- head observations for the DVRFS ground-water flow model, nearly all available water levels for the DVRFS region through 2004 were compiled in Ground-Water Site Inventory (GWSI), the ground-water component of the U.S. Geological Survey (USGS) National Water Information System (NWIS) database. Water levels suitable for developing hydraulic-head observations representative of regional, steady-state ground-water flow conditions were identified through analyses. The resulting water levels were averaged for each well to produce one hydraulic-head observation value at each of 700 wells. The uncertainty of each hydraulic-head observation was statistically quantified from the values of uncertainties associated with well altitude and location, nonsimulated transient stress, and measurement accuracy.