Underground storage of imported water in the San Gorgonio Pass area, California

Geologic and geophysical maps of the El Casco 7.5′ quadrangle, Riverside County, southern California, with accompanying geologic-map database

“…1). There, marshy ground and artesian springs reported by Bloyd (1971;also see Mendenhall, 1905) indicate a groundwater barrier that requires a geologic explanation. A fault in this vicinity would provide such a barrier, and although no fault has been identified or mapped there on the basis of surface exposures, the inferred San Timoteo Fault may play a role in ponding groundwater.…”

“…Hydrologic investigations by the U.S. Geological Survey (Bloyd, 1971;Rewis and others, 2006) indicate that groundwater in the Beaumont-Cherry Valley storage area (as used by Bloyd, 1971) flows southwest toward the center of the El Casco quadrangle; there, it rises to the surface in the large unnamed canyon downstream from the intersection of Singleton Road and Interstate Highway 10 ( fig. 1).…”

“…Important structural and stratigraphic elements include (1) modern traces of the right-lateral San Jacinto Fault zone, (2) older traces of the San Jacinto Fault zone, and (3) sedimentary materials and geologic structures that formed during the last eight million years or so and that record interactions within the San Andreas Fault system. These materials, and the structures that deform them, provide a geologic context for investigations of groundwater recharge and subsurface flow (Waring, 1919;Burnham and Dutcher, 1960;Bloyd, 1971;Rewis and others, 2006). This geologic database of the El Casco 7.5′ quadrangle was prepared by the Basins and Landscape Co-Evolution Project (BALANCE), a regional geologic-mapping project sponsored jointly by the U.S. Geological Survey and the California Geological Survey.…”

Estimating natural recharge in San Gorgonio Pass watersheds, California, 1913–2012

“…1B). This area includes the groundwater storage units identified by Bloyd (1971). The area of interest for these groundwater studies is referred to as the San Gorgonio Pass groundwater study area (SGPGSA) in this report.…”

“…The SGPWA has developed an extensive groundwater database to help manage and protect the local groundwater-storage units identified by Bloyd (1971). Groundwater levels near Beaumont declined by as much as 100 feet (ft) between the early 1920s and early 2000s, and numerous natural springs have stopped flowing in the San Timoteo subbasin (Bloyd, 1971).…”