Mold Remediation in Guerneville & the Russian River, CA
Guerneville, Monte Rio and Forestville live with the river, the fog and the redwoods, and all three bring water into houses. Santa Rosa Mold Pros is a free quote service: describe the problem once, and independent companies that work along the lower Russian River reply with quotes.
Get a Free QuoteHow high the river has come
The National Weather Service gauge at Guerneville puts flood stage at 32 feet, about 16 miles west of Santa Rosa, CA. Recent and record crests:
| Date | Crest | Note |
|---|---|---|
| Feb 18, 1986 | 49.5 ft | Record |
| Jan 10, 1995 | 48.0 ft | Major |
| Feb 27, 2019 | 45.38 ft | Highest since 1995 |
| Jan 11, 2017 | 37.82 ft | Moderate |
| Jan 10, 2023 | 31.83 ft | Just under flood stage |
After the February 2019 flood, Sonoma County's early estimate counted about 1,900 homes affected countywide and roughly $155 million in damage. Federal disaster declarations covered Sonoma County storms in 2017, 2019 and January 2023.
Much of Guerneville's housing has since been raised, largely with FEMA grants. That helps, but water under an elevated house still soaks the soil, insulation and floor framing above it.
After the water drops: the first few days
Stay safe, then document
Wait until officials say it is safe, keep power off in wet areas, and photograph every room and the crawl space before moving anything. Call your flood insurer.
Get wet material out
River water is dirty water. Drywall, insulation and carpet pad it touched usually need removal, not just drying. The EPA advises drying wet materials within 24 to 48 hours.
Dry the structure
Air movers and dehumidifiers on framing, subfloor and crawl space. Moisture readings, not the look of the wood, say when it is dry.
Watch who you hire
After a declared disaster, California generally gives you seven days to cancel a repair contract, and unlicensed disaster-repair work is a crime. Check the CSLB license before paying any deposit.
Cabins, fog and the off-season
Guerneville has the oldest housing on this site. The median home was built in 1955, 81.5% before 1980 and about a third in 1939 or earlier (ACS 2024 5-year). Roughly a quarter of the housing, 788 of about 3,181 units, is held for seasonal or occasional use.
Fog moves up the river from the Pacific, and fog drip keeps the redwoods wet even in summer. Put an old cabin in that shade, close it up for the winter, and walls, closets and crawl spaces never get a chance to dry. Many owners first find mold when they open the house in spring. The crawl space page explains what companies check under the floor.
Before tear-out in a cabin this old, ask about an asbestos survey, and for painted surfaces ask whether the company is EPA Lead-Safe Certified.
Monte Rio and Forestville
Monte Rio sits downriver and shares Guerneville's flood exposure; local news reports described both as cut off by high water in 2019. Forestville homes away from the floodplain still deal with the same shade, fog and winter rain, which tends to show up in crawl spaces and closets.
All three communities are unincorporated, so permits go through Permit Sonoma, which exempts minor drywall repair only up to 100 sq ft. Larger drywall replacement, plumbing, electrical and structural work generally needs a permit and a CSLB-licensed contractor.
Published estimates, not quotes: crawl spaces often run $500–$2,000 and whole-house work $10,000–$30,000 (Fixr 2025). Quotes come from the companies; see the cost guide and mold after floods and storms.
Russian River mold questions
Does flood insurance cover mold after a Russian River flood?
Flood damage needs a separate flood insurance policy, because California homeowners policies exclude flood. Whether mold cleanup is paid depends on that policy's terms. Report the loss promptly, photograph everything before it is removed and ask the insurer in writing what is covered. Nobody can promise coverage, and this site does not handle claims.
My cabin was closed all winter and smells musty. Where do I start?
Open windows if the air outside is drier, run the heat for a day and check closets on outside walls, under sinks and around the crawl space access. Don't scrub large areas or blow fans across growth, which spreads spores. If growth covers more than a small patch or the smell has no clear source, ask for an inspection.
Can I get quotes in Monte Rio and Forestville?
Yes. Requests from Monte Rio, Forestville, Guerneville and nearby river communities go to independent companies that say they work along the lower Russian River. Roads can close during high water, so mention if your home is hard to reach. These communities are unincorporated, so building permits go through Permit Sonoma.
Nearby towns and services
Get quotes along the Russian River
Tell us the community, whether the water came from the river, rain or a pipe, and whether the house is lived in year-round. Independent companies reply directly, with no obligation. Or call (707) 896-6015.
Seeing or smelling mold? Get a clear plan.
Free, no-pressure quotes from independent companies across Santa Rosa, Petaluma, Rohnert Park, Windsor and Sonoma County.