Sebastopol's flood risk comes mostly from the Laguna de Santa Rosa, which drains to the Russian River and backs up when the river is high. The CNRFC's Laguna gauge at Sebastopol has an action stage of 67 feet and minor flooding at 69 feet, when Occidental Road begins flooding near the channel (CNRFC).
Recent flooding
In February 2025, the Sebastopol Times reported Petaluma Avenue flooding near the Joe Rodota Trail, Morris Street closing between Highway 12 and the Community Center, and the Laguna rising onto part of Morris Street as the Russian River peaked at 36.32 feet (Sebastopol Times). That's local news reporting, not an official tally.
Why mold follows
- Slow drying. West county's shade and fog keep materials damp.
- Crawlspaces under older homes collect water.
- Contaminated water. Laguna floodwater should be handled like any floodwater; the EPA recommends experienced professionals (EPA).
What to do
- Prepare: the City of Sebastopol offers free sand and bags to residents at 425 Morris Street, up to 25 bags (City of Sebastopol).
- If water gets in, document, remove water and soaked porous materials, and dry within 24 to 48 hours if possible (EPA).
- Watch both the Laguna gauge and the Guerneville forecast.
Want a local pro to take a look?It's free for homeowners and there's no obligation.
Related
- Laguna flood cleanup in Sebastopol on Sonoma County Water Damage
- Roof repair in Sebastopol on Sonoma Roof Repair
- Crawlspace mold
Sources
- CNRFC: Laguna de Santa Rosa at Sebastopol
- Sebastopol Times: Sebastopol flood diary (Feb 2025)
- City of Sebastopol: Sandbags
- EPA: Mold cleanup in your home
- EPA: A Brief Guide to Mold, Moisture and Your Home
- CNRFC: Russian River at Guerneville
Sources checked October 18, 2026.
Frequently asked questions
Why does the Laguna flood when it isn't raining hard in Sebastopol?
The Laguna drains to the Russian River. When the river is high, the Laguna can back up, so watch river forecasts too.
Should I test for mold after a flood?
CDPH says testing isn't needed if you can see or smell mold or moisture. Focus on drying and removing damaged materials.