San Gabriel Valley
Statistics
- Basin Name
- San Gabriel Valley
- Basin Number
- 4-013
- SGMA Basin Priority
- Very Low
- Critically Overdrafted
- No
- Hydrologic Region Name
- South Coast Hydrologic Region
- Counties
- Los Angeles
At-A-Glance
Located in California’s hydrologic region, the San Gabriel Valley is 126,379 acres in size. This Very Low priority basin is home to an estimated 1,267,729 people (2010 value), which have been at a rate of 2.34.
San Gabriel Valley is a(n) basin with approximately 1463 wells, of which approximately 242 are water supply wells. Groundwater accounts for approximately 73.65 percent of the basin’s water supply.

Basin Notes
2003: Bulletin 118 basin description
2014: CASGEM basin priority – high. Comment – Superfund sites in basin.
2018: Draft basin prioritization – very low. Comments:
- 1) CASGEM/WDL/GWIDS: Long term hydrographs more or less stable. Source: DWR
- 2) Water Master Annual report hydrograph for key well shows a decline of about 50 feet since 1989. Source: Main San Gabriel Basin Watermaster Annual Report 2015-2016
2017-18 Main San Gabriel Basin Watermaster Annual Report; previous yearly reports
Basin 97.01 adjudicated. Web page: Main San Gabriel Basin Watermaster
2018 Final Basin Prioritization: Basin priority is changed from high to very low.