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The role of the unsaturated zone in artificial recharge at San Gorgonio Pass, California

August 1, 2004

The hydrogeology of the unsaturated zone plays a critical role in determining the suitability of a site for artificial recharge. Optimally, a suitable site has highly permeable soils, a capacity for horizontal flow at the aquifer boundary, a lack of impeding layers, and a thick unsaturated zone. The suitability of a site is often determined by field and laboratory measurements of soil properties, field experiments, and numerical modeling. An artificial recharge site in the San Gorgonio Pass area in southern California, USA was studied to better understand the role of the unsaturated zone in artificial recharge by surface spreading. Field measurements and observations were used to characterize the site and to develop a conceptual model of the unsaturated zone. A numerical model was developed based on the conceptual model and calibrated using data from a 50-d artificial recharge experiment conducted in 1991 and borehole data collected between 1997 and 2002. Results indicate that an impeding layer exists 70 m below land surface that will cause lateral diversion of artificially recharged water, which would spread out and delay recharge to the water table 185 m below land surface.

Citation Information

Publication Year 2004
Title The role of the unsaturated zone in artificial recharge at San Gorgonio Pass, California
DOI 10.2136/vzj2004.0763
Authors Alan L. Flint, Kevin M. Ellett
Publication Type Article
Publication Subtype Journal Article
Series Title Vadose Zone Journal
Series Number
Index ID 70199578
Record Source USGS Publications Warehouse
USGS Organization California Water Science Center

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