Delineation of Potential Groundwater Discharge Boundaries and Evapotranspiration Units in Nevada

Potential areas of groundwater discharge (i.e., potential areas of groundwater evapotranspiration) in Nevada were identified and mapped using previously published groundwater studies in the State, as well as a number of ancillary data sets. Reconnaissance Series and Water Resource Bulletin investigations conducted between 1940 and 1980 resulted in numerous reports containing original delineations of potential areas of groundwater discharge for many of the hydrographic areas (HAs) in Nevada (e.g., Maxey and Eakin, 1949; Eakin, 1962; Cohen, 1964; Eakin et al., 1965; Rush and Everett, 1966; Everett and Rush, 1966; Harrill and Moore, 1970; Glancy and Katzer, 1975). The rest of these published reports are available to the public on the Nevada Division of Water Resources’ (NDWR) website (http://water.nv.gov/index.aspx). More recent studies conducted by the U.S. Geological Survey (USGS) have provided supplemental delineations of potential areas of groundwater discharge and evapotranspiration units (ET units) for select HAs (Smith et al., 2007, Garcia et al., 2015; Berger et al., 2016), as well as new boundaries for previously unreported HAs (Berger, 2000; Plume and Smith, 2013). Boundaries from these more recent studies were incorporated into the statewide data set to increase the areal coverage and to compare them with the previous delineations when available. A total of 187 HAs are covered by this data set; a map showing which HAs contain discharge boundaries and another that shows the areal extent of the data set are shown in figures 1 and 2, respectively.