Observation of ephemeral flows and estimation of recharge from the Inyo and Coso Mountains, Owens Dry Lake, California

Dust from Owens Lake Playa is a serious environmental problem. Groundwater from the Owens Dry Lake Basin is being considered for dust mitigation. This thesis provides a preliminary estimate of groundwater recharge from the Inyo and Coso Mountains, the northeast and southeast boundaries of the basin. Prior to this study, no previous measurements of precipitation, infiltration, ephemeral stream flows, soil water chemistry, or runoff water chemistry were available from the Inyo and Coso Mountains. These data were collected and four methods of estimating groundwater recharge were applied: (1) direct measurement of stream channel transmission losses, (2) the chloride mass balance method, (3) the Maxey-Eakin method, and (4) the water balance approach. Estimates of recharge using methods (1) and (2) were approximately 350-750 acre-ft/yr. Estimates of recharge using the Maxey-Eakin method and the water balance approach were approximately 1,100-2,000 acre-feet/year and 1,500-3,200 acre-feet/year, respectively. The relatively low values from methods (1) and (2) were primarily due to uncertainties in estimating average annual runoff. The estimated value obtained by the water balance approach appears to be the most reasonable value because this method incorporated actual field measured data.