Simulating the effects of artificial recharge in Lemmon Valley, Washoe County, Nevada

Abstract

A quasi three-dimensional finite difference numerical groundwater flow model was developed to simulate the effects of artificial recharge in a topographically-closed basin in western Nevada. The basin was conceptualized as a two-layer groundwater system, an upper unconfined layer and a lower confined layer. Components of the modeled water budget include precipitation, subsurface inflow and outflow, and evapotranspiration. Other water budget components, groundwater pumpage and secondary recharge, were incorporated into the model implicitly. Stable water levels on an annual basis, along with recharge and discharge components of the water budget being nearly equal, indicate that the groundwater system was at quasi steady-state during the early 1970s. Accordingly, model calibration was completed using a quasi steady-state calibration process. Results of model calibration were the initial conditions for transient simulations of artificial recharge. All simulations indicate that artificial recharge adds water to aquifer storage and increases water levels.