A basin-scale approach to estimating recharge in the desert: Anza-Cahuilla groundwater basin, CA

Journal of the American Water Resources Association
By: , and 

Links

Abstract

The Anza-Cahuilla groundwater basin located mainly in the semi-arid headwaters of the Santa Margarita River watershed in southern California is the principle source of groundwater for a rural disadvantaged community and two Native American Tribes, the Ramona Band of Cahuilla and the Cahuilla. Groundwater in the study area is derived entirely from precipitation and managing groundwater sustainably requires an accurate assessment of the water balance components, yet long-term estimates do not exist. Demand for groundwater in the region has increased and groundwater quality has decreased due to population growth and increased irrigated cropland. To characterize monthly long-term natural recharge and runoff estimates, a physically-based water balance model (Basin Characterization Model) was locally calibrated and validated using nearby streamgages and published estimates of climatic and hydrologic variables. The average modeled annual recharge and runoff from 1981 to 2010 was 5.4 × 106 and 1.2 × 107 m3, respectively, for the study area. Recharge and runoff do not reliably occur in large amounts every year and recharge rarely occurs in the groundwater basin footprint. These long-term estimates can be used by water managers, stakeholders, and Native American Tribes to develop plans for sustainable management of future water resources, and as inputs to a three-dimensional groundwater model.

Study Area

Publication type Article
Publication Subtype Journal Article
Title A basin-scale approach to estimating recharge in the desert: Anza-Cahuilla groundwater basin, CA
Series title Journal of the American Water Resources Association
DOI 10.1111/1752-1688.12971
Edition Online First
Year Published 2021
Language English
Publisher Wiley
Contributing office(s) California Water Science Center
Country United States
State California
Other Geospatial Anza-Cahuilla groundwater basin
Google Analytic Metrics Metrics page
Additional publication details