Napa-Sonoma Valley – Sonoma Valley

Napa-Sonoma Valley – Sonoma Valley


  • Basin Name
  • Napa-Sonoma Valley – Sonoma Valley
  • Basin Number
  • 2-002.02
  • SGMA Basin Priority
  • High
  • Critically Overdrafted
  • No
  • Status
  • Developing a GSP
  • DWR Region & POC
  • Northern Central Region Office
    Ted Bedegrew
    (916) 376-9619

  • Number of Wells
  • 1287
  • Hydrologic Region Name
  • San Francisco Bay
  • Counties
  • Sonoma


Located in California’s San Francisco Bay hydrologic region, the Napa-Sonoma Valley – Sonoma Valley is 44,846.18 acres in size. This High priority basin is home to an estimated 31,275 people (2010 value), which have been at a rate of . Napa-Sonoma Valley – Sonoma Valley is a(n) basin with approximately 1287 wells, of which approximately 42 are water supply wells. Groundwater accounts for approximately 64 percent of the basin’s water supply.

Source: CA DWR

Basin Notes

2003: Bulletin 118 basin description 

2007: Sonoma Valley Groundwater Management Program

2014: Sonoma Valley Groundwater Management Program Five Year Review and Update

2019: Basin boundary modification approved. Per DWR: It “revises and aligns the shared boundary between Sonoma Valley and Sonoma Lowlands to follow the shared Sonoma and Napa County line.” Phase 2 Draft prioritization: high.

GSA Information