Policy and rulesGuide
Who manages groundwater in Sonoma County
Three basins have approved groundwater sustainability plans: Sonoma Valley, Petaluma Valley and Santa Rosa Plain. Each has its own local agency.
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| Basin | Agency | Plan approved |
|---|---|---|
| Sonoma Valley | Sonoma Valley GSA | December 6, 2021 |
| Petaluma Valley | Petaluma Valley GSA | December 8, 2021 |
| Santa Rosa Plain | Santa Rosa Plain GSA | December 9, 2021 |
GSA means groundwater sustainability agency. Each board approved its plan unanimously.
What this means if you have a well
Find out which basin you are over. The water map shows it. Wells in hills often draw from rock, which the map does not cover.
For permits, call Permit Sonoma. For testing, see how often to test your well.
Sources
Checked 2026-10-11. Rules and programs change. If something here is out of date, the source above wins. Spot an error? See our corrections policy.
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