Update to the Groundwater Withdrawals Database for the Death Valley Regional Groundwater Flow System, Nevada and California, 1913-2016 (ver. 2.0, July 2021)

Groundwater withdrawal estimates for 1913-2016 for the Death Valley regional groundwater flow system (DVRFS) are compiled in this Microsoft® Access database to support a regional, three-dimensional, transient groundwater flow model (Belcher and others, 2017; Halford and Jackson, 2020). This database (version 2) updates previously published databases that compiled estimates of groundwater withdrawals for 1913-1998 (Moreo and others, 2003), 1913-2003 (Moreo and Justet, 2008), and 1913-2010 (Elliott and Moreo, 2018; version 1 of this data release). Version 2 of this data release is the most current version of the database and supersedes all previous versions.
A total of about 41,000 acre-ft of groundwater were withdrawn from DVRFS in 2016 of which 51 percent was used for irrigation, 20 percent for domestic, and 27 percent for public supply, commercial, and mining activities.
The total groundwater withdrawals for Pahrump Valley (hydrographic area 162) increased from 17,000 acre-ft in 2010 to 19,900 acre-ft in 2016. During the same period irrigation withdrawals increased from 3,700 to 5,900 acre-ft and other water uses, primarily public supply and domestic, increased from 13,300 to 14,000 acre-ft. The increase in total water use is attributed primarily to an increase in irrigated acreage. Total irrigated acreage increased from 720 acres in 2010 to 1,100 acres in 2016. 
The total groundwater withdrawals for Amargosa Desert (hydrographic area 230) in 2010 (18,100 acre-ft) were similar to 2016 (18,400 acre-ft). Irrigation withdrawals for 2016 totaled 15,100 acre-ft. In 2010, 800 of 2,460 irrigated acres were metered (33 percent). By 2016, 1,370 of 2,700 irrigated acres were metered (51 percent). Due to this increase in the number of metered irrigated fields, metered irrigation withdrawals continue to be compiled as reported instead of compiling acreage and applying estimated application rates as was done for previous database versions (Moreo and others, 2003; Moreo and Justet, 2008). The mean application rate for metered fields (5.4 ft/yr) was lower than the mean application rate estimated for fields without meters (6.5 ft/yr; Moreo and Justet, 2008). It is unclear whether the mean application rate for metered fields is representative of application rates in fields that are not metered. An accuracy of ± 5 percent is assumed for all metered withdrawals.
Groundwater withdrawals for all water-use categories other than irrigation in Amargosa Desert were 3,300 acre-ft in 2016 (18 percent of total withdrawals). Commercial water use decreased from 2,200 acre-ft in 2010 to 1,800 acre-ft in 2016. Groundwater use for mining increased from 310 acre-ft in 2010 (less than 2 percent) to 690 acre-ft in 2016 (4 percent). This increase in mining use can be attributed to an increase in water usage by Industrial Mineral Ventures Nevada. Domestic and public supply water use in 2016 was 830 acre-ft, about 4 percent of the total water use.
Other significant areas of groundwater withdrawals are Penoyer Valley (hydrographic area 170) and the Nevada National Security Site (NNSS). Penoyer Valley was excluded from this update because it lies outside of the version 3 model boundary; however, it should be noted that withdrawal estimates through 2003 and withdrawal points for Penoyer Valley and other areas outside of the DVRFS version 3 preliminary boundary but within the DVRFS version 2 boundary have not been removed from the database. Groundwater withdrawals supporting NNSS activities were updated for the period of record based on updated estimates published by Elliott and Moreo (2011) and U.S. Geological Survey (2017).

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Organization: Department of the Interior