2008 Joint Annual Meeting (5-9 Oct. 2008): Recharge Analyses In a Desert Groundwater Basin

Groundwater recharge is a basis for assigning water rights in some western states and is a consideration in the analysis of developing a sustainable water supply. A variety of field methods to quantify recharge were applied in an undeveloped area within Nevada's Basin and Range Physiographic Province where mean annual precipitation is about eleven inches. This paper describes the field data collected and our interpretation of recharge processes including mountain block recharge, ephemeral channel infiltration, and diffuse recharge. We also compare the results of the chloride mass balance method, transfer function calculations (e.g., Maxey-Eakin method), and a newly developed distributed parameter soil-water balance model of the basin. We also developed new coefficients for the Maxey-Eakin method, based on updated precipitation data for the basins which Maxey and Eakin used to derive their method more than 50 years ago. A comparison of the methods indicates the central tendency for recharge is several percent of mean annual precipitation.