Numerical Simulation of Groundwater Withdrawal within the Mercury Valley Administrative Groundwater Basin, Nevada

Gilliam, A.B. ; Carroll, R.W.H. ; Pohll, G. ; Hershey, R.L.

Desert Research Institute, Nevada Division of Higher Education

关键词: Pumping;    Ground Water;    Computerized Simulation;    Nevada Test Site;    Water Supply;   

DOI  :  10.2172/876751
RP-ID  :  DOE/NV/13609--43
RP-ID  :  DRI Pub. No. 45214
RP-ID  :  876751

美国|英语

来源: UNT Digital Library

【 摘 要 】

A detailed, transient, three-dimensional, finite-difference groundwater flow model was created for the Mercury Valley Administrative Groundwater Basin (MVB). The MVB is a distinct groundwater basin as defined by the State of Nevada and is located partially within the boundary of the Nevada Test Site. This basin is being studied as a potential location for new industrial facilities and therefore would be subject to Nevada water-use limitations. The MVB model was used to estimate the volume of water that could be withdrawn from Mercury Valley without inducing laterally or vertically extensive water-table effects. In each model simulation, water-table drawdown was limited to a maximum of 0.5 m at the boundary of the basin and held within the screened interval of the well. Water withdrawal from Nevada groundwater basins is also limited to the State-defined perennial yield for that area. The perennial yield for the MVB is 27,036 m{sup 3}/day. The one existing water-supply well in Mercury Valley is capable of sustaining significantly higher withdrawal rates than it currently produces. Simulations showed this single well could produce 50 percent of the basin?s perennial yield with limited water-table drawdown. Pumping from six hypothetical water-supply wells was also simulated. Each hypothetical well was placed in an area of high hydraulic conductivity and far from the basin's boundaries. Each of these wells was capable of producing at least 50 percent of the basin's perennial yield. One of the hypothetical wells could simulate 100 percent of the perennial yield while staying within drawdown limitations. Multi-well simulations where two or more water-supply wells were simultaneously pumping were also conducted. These simulations almost always resulted in very limited lateral and vertical drawdown and produced 100 percent of Mercury Valley's perennial yield. A water-budget analysis was also conducted for each of the various stress simulations. Each of the stress scenarios was compared to a baseline scenario where existing water-supply wells in the model domain were pumped at 2003-2004 average pumping rates. Water-budget analyses showed increased flow from the constant-head boundaries on the north, east, and west sides of the model. Flow to the southern, head-dependent boundary and to springs in the Ash Meadows area remained unchanged.