San Diego River Valley

Statistics

Basin Name

Basin Number

9-015

SGMA Basin Priority

Very Low

Critically Overdrafted

Status

Not Subject to SGMA

DWR Region & POC

Southern Region

Number of Wells

Hydrologic Region Name

South Coast Hydrologic Region

Counties

San Diego

Adjacent Basins

El Cajon Valley (9-016),

At-A-Glance

Located in California’s hydrologic region, the San Diego River Valley is 9,873.37 acres in size. This Very Low priority basin is home to an estimated 40,629 people (2010 value), which have been at a rate of 14.97. San Diego River Valley is a(n) basin with approximately 91 wells, of which approximately 5 are water supply wells. Groundwater accounts for approximately 4 percent of the basin’s water supply.

2004: Bulletin 118 basin description

2014: CASGEM basin prioritization – medium. Comments: High nitrates, iron and manganese treatment is required. High TDS ( >3,000 mg/l) in western portion of basin

2018: Draft basin priority – very low. Comments: no documentation available on groundwater levels/declines. Salt intrusion –

1) The groundwater is characterized with moderate to high levels of salinity. A recent study by USGS evaluated the sources and movement of saline groundwater in these groundwater basins (USGS 2013b). The chloride concentrations ranged from 57 to 39,400 mg/L. The sources of salinity were natural geologic sources and sea water intrusion. Source: Chapter 7, EIS, Coordinated Long-Term Operation of the Central Valley Project and State Water Project, U.S. Bureau of Reclamation

2019: Basin boundary modification. Per DWR: It “follows geologic contacts on a 1:100,000 scale qualified map, which is a more detailed mapping scale than the 1:250,000 scale maps used in 2016. Colluvium deposits are excluded from the upper reaches of the proposed basin. These deposits are thin, dry layers above non-permeable, consolidated deposits.” Phase 2 draft priority: very low