Overnight storms did more than just soak Guerneville yesterday; they overwhelmed the Russian River treatment plant south of town and sent untreated wastewater toward the lower Russian River, prompting health warnings along one of Sonoma County's most iconic waterways. Local alert messages went out to nearby households, crews posted signs at popular river and coastal access points, and environmental specialists deployed for on-site assessments.
What Sonoma Water Says
Sonoma Water reports that the Russian River Treatment Plant on Neeley Road was hit with an atmospheric river that pushed flows to roughly four million gallons per day, far above the facility's design capacity of about 710,000 gallons per day, according to Sonoma Water. The agency says some of the discharge traveled about a quarter mile through a forested area before reaching the river's mainstem and noted that river levels were already elevated at the Hacienda Bridge during the incident.
Warnings, Closures and River Conditions
The Sonoma County Sheriff's Office has advised the public to stay out of the Russian River from downstream of the treatment plant all the way to Jenner, and local officials say Russian River and select Sonoma Coast access points are being posted with warning signs, as reported by CBS News. Authorities are asking paddlers, swimmers and other river users to steer clear while crews and environmental specialists evaluate any hazards tied to the overflow.
Officials Offer Few Details As Cleanup Continues
Sonoma Water and county officials are calling the spill an ongoing situation and, so far, have not given a firm timeline for cleanup and water quality testing, The Press Democrat reported, citing Sonoma Water's public information officer. According to that account, officials are still working to determine how many residents are affected and how much of the overflow ultimately reached the river's mainstem.
How Residents Can Protect Themselves
Officials warn that untreated wastewater can carry bacteria and other pathogens and are urging people to avoid contact with the Russian River for now, especially children, pets, older adults and anyone with a weakened immune system. Customers in the service area are also being asked to cut back on wastewater use, such as shortening showers, delaying laundry and limiting flushing where possible, while crews work to stabilize the system, per Sonoma Water.
A Recent History Of Spills
Locals have seen this play out before. In March 2024, a storm-related power outage combined with equipment failures led to a spill of roughly 277,000 gallons of secondary-treated wastewater that reached the river. Sonoma County later published details of that event and its follow-up assessment, a reminder of why local crews are especially cautious now. As with Tuesday's overflow, that earlier incident triggered notifications to regulators and environmental monitoring in the field.
Officials say more information will be released as sampling and assessments continue, and community members are being encouraged to keep an eye on agency updates and local emergency pages for the latest guidance.
