Implementation of Operating Criteria and Procedures for Newlands Project irrigation and Public Law 101-618 could result in significant reductions of surface water used for agriculture in the Carson Desert, Nevada and thereby could affect recharge through the aquifer system and local groundwater supply. This report summarizes previous studies on how the aquifers are recharged and what controls groundwater flow and quality. A near-surface saturated zone could exist at the top of the shallow aquifer near the central and eastern parts of the basin, where underlying clay beds impede vertical flow. In the basalt aquifer, water levels have declined about 10 ft from pre-pumping levels, and chloride and arsenic concentrations have increased. Conceptual models of the basin suggest that changes in water use in the western part of the basin would probably affect recharge to the shallow, inter- mediate, and basalt aquifers. Installing impermeable lining in canals and removing adjacent land from production could cause water-level declines more than 10 ft in the shallow aquifer as far as 2 mi from lined canals. Reducing recharge to the shallow aquifer by 25,000-50,000 acre-ft/yr beneath 30,000 acres could cause water levels to decline from 4 to 17 ft, depending on the distri- bution of specific yield in the basin. Where water is pumped from a near-surface zone of the shallow aquifer, lower water levels might not greatly affect pumping wells where the zone is thickest, but could cause wells to go dry where the zone is thin.
Additional Publication Details
USGS Numbered Series
Hydrogeology and potential effects of changes in water use, Carson Desert agricultural area, Churchill County, Nevada
U.S. Geological Survey ;
U.S.G.S. Earth Science Information Center, Open-File Reports Services [distributor],