Regional Water Balance for the Waste Isolation Pilot Plant (WIPP) Site and Surrounding Area

摘要

The WIPP water-balance study area defined here comprises approx.2000 mi exp 2 in Eddy and Lea Counties, southeastern New Mexico. Inflows to the study area are precipitation (roughly 1.47 x 10 exp 6 ac-ft/y), surface water (roughly 1.1 x 10 exp 5 ac-ft/y), water imported by municipalities and industries (roughly 3 x 10 exp 4 ac-ft/y), and ground water (volume not estimated). Outflows from the area are evapotranspiration (roughly 1.5 x 10 exp 6 ac-ft/y), surface water (roughly 1.2 x 10 exp 5 ac-ft/y), and possibly some ground water. The volume of surface and ground water in storage in Nash Draw has increased since the beginning of potash refining. Regional ground-water flow in aquifers above the Salado Formation is from the northeast to the southwest, although this pattern is interrupted by Clayton Basin, Nash Draw, and San Simon Swale. The Pecos River is the only important perennial stream. Most of the area has no integrated surface-water drainage. The available data suggest that approx.1600 mi exp 2 of the study area are hydrologically separate from Nash Draw and the WIPP site. Ground water north of Highway 180 apparently discharges into Clayton Basin and evaporates. Water in San Simon Swale apparently percolates downward and flows to the southeast. Data are inadequate to create a water budget for the Nash Draw-WIPP site hydrologic system alone, although an attempt to do so can provide guidance for further study. (ERA citation 11:017613)