Simulated changes in ground-water flow caused by hypothetical pumping in east Carson Valley, Douglas County, Nevada

An existing groundwater model of Carson Valley was used to simulate changes in groundwater flow on the east side of Carson Valley, Nevada, in response to hypothetical increases in groundwater pumpage. Pumpage scenarios that reflect State groundwater permits and pending applications were used in four different simulations to estimate the effect of hypothetical development on groundwater levels and storage, groundwater flow to the Carson River, and groundwater levels and storage, groundwater flow to the Carson River, and groundwater consumed by evapotranspiration over a 45-yr period. The four simulations were based on pumpage rates ranging from 0.13 to 6.4 cu ft/sec (92 to 4,590 acre-ft/year). Changes in groundwater flow and water levels caused by the lowest rate were minimal and at the limit of accuracy of the groundwater model. The highest pumping rate caused water level declines as much as 15 ft, decreased groundwater storage by 27,000 acre/ft, decreased groundwater to the Carson River by 4.3 cu ft/sec (3,100 acre-ft/year), and reduced evapotranspiration losses by about 1,200 acre-ft/year. (Author 's abstract)