An investigation of the potential for surficial recharge in the Lucerne Valley groundwater basin, Mojave Desert, CA

To better understand the characteristics of recharge within the Lucerne Valley groundwater basin, a series of infiltration tests, soil analyses and computer simulations were conducted throughout the watershed. Previous studies have suggested that because desert valleys receive less than eight inches of annual precipitation and have a deep, unsaturated zone, natural recharge cannot occur. Within the Lucerne Valley, gaps in a recent water budget, increasing groundwater levels, and geochemical analysis of groundwater samples indicate that additional recharge must be occurring within the valley. Studies elsewhere in the Mojave Desert have suggested that recharge can occur during heavy precipitation as infiltration of stream flow in ephemeral channels. Field investigations (infiltration tests, stream measurements, and soil sample collection) and laboratory tests (sieve analyses, chloride tests, falling-head permeameter and moisture content) were conducted in the Lucerne Creek, alluvial fan/fill and the Lucerne (Dry) Lake. Results suggest that a source of recharge exists in the Lucerne Creek. Using numerical modeling, estimated volumes of recharge were determined for precipitation events of less than 1-year, 1-year, 2-year, and 5-year frequencies. This research is intended to better understand the natural recharge of surface water in the Lucerne Valley groundwater basin. Furthermore, this research may provide a cost-effective method to determine potential recharge in other basins and better understand surficial recharge in desert environments.