To: Board of Supervisors, County of Sonoma
Department or Agency Name(s): Emergency Management, Sonoma Water, Public Infrastructure, Regional Parks
Staff Name and Phone Number: Jeff DuVall, CEM / 707-565-1152; Brad Sherwood / (707) 547-1900; Johannes Hoevertsz / 707-565-2550; Bert Whitaker / 707-565-2041
Vote Requirement: Majority
Supervisorial District(s): Countywide
Title:
Title
Annual Flood Preparedness Update
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Recommended Action:
Recommended action
Receive an update on Flood Preparedness and adopt a concurrent Resolution recognizing the elevated 2026/2027 El Niño season and directing accelerated El Niño preparedness.
end
Executive Summary:
The flood preparedness update will be an information-sharing session where staff will provide preparedness information on: the upcoming 2026 winter/flood season projects, County/Operational Area readiness, Emergency Management’s (DEM) preparedness efforts, and regional collaboration efforts with local cities, special districts, and state agencies, such as California Governor's Office of Emergency Services (CalOES), California Department of Water Resources (DWR). In addition, Public Infrastructure, Regional Parks, and Sonoma Water will present an overview of seasonal preparedness efforts and an overview of key flood projects across the county.
Discussion:
Over the past six years, Sonoma County has experienced 14 locally proclaimed disasters, including wildfires, floods, droughts, and public safety power shutoffs. As the County enters another winter season, departments are preparing for strong winds, atmospheric rivers, flooding, and periods of freezing temperatures.
El Niño conditions are expected to develop for winter 2026-27, but El Niño alone does not determine how much rain Sonoma County will receive. The timing of individual storms and other weather patterns will matter, especially in Northern California. County staff will continue to work with the National Weather Service and monitor forecasts as the season develops. High sea and bay levels may add to flooding in low-lying coastal and bayside areas, while cold weather can put people, animals, and crops at risk.
The Department of Emergency Management (DEM) is preparing to increase staffing during significant storms through its duty officer program and activate its Department Operations Center or the County Emergency Operations Center when conditions warrant. DEM is bringing Operational Area partners together for a flood-season briefing, training EOC staff, and preparing the Lower Russian River Incident Command Post in Graton. DEM has reviewed specific alert and warning procedures, will expand the Russian River Flood Annex into a countywide flood plan by the end of the calendar year, and will improve flood monitoring where gauge data is limited, in partnership with Sonoma Water in the future. Community outreach includes direct contact with mobile home parks along the Russian River. DEM maintains storm assistance kits after a major flood event; portable energy resilience kits and sandbags will help community members prepare and respond to storm impacts.
Sonoma Water’s winter work includes sediment removal, vegetation management, trash removal, and maintenance of flood-control channels. From 2020 through 2025, its stream maintenance program removed 85,466 cubic yards of sediment, completed sediment removal along 6.7 miles of waterways, and maintained vegetation along about 128 miles. Crews removed 282,839 pounds of trash from 2023 through 2026. Weekly channel cleanups and daily coordination with Santa Rosa and Rohnert Park continue. Sonoma Water is also maintaining its OneRain system, which provides real-time rainfall, stream, and reservoir information. New gauges are being installed at Fife Creek and Willowbrook Creek in partnership with Public Infrastructure and Sonoma Water. DEM and Sonoma Water are collaborating on a potential countywide expansion of the OneRain system. Sonoma Water is reviewing construction projects, assessing other infrastructure, and identifying priority risks and actions for the coming season. It continues to coordinate with the U.S. Army Corps of Engineers on storage and releases at Lake Sonoma and Lake Mendocino.
The Department of Public Infrastructure is inspecting and clearing culverts, roadside ditches, swales, and bridge drainage areas. Crews are reviewing roads and structures with a history of flooding or slides, checking monitoring systems at flood-prone locations, and staging sandbags, barricades, signs, and response equipment. Road Maintenance, Facilities, Engineering, Fleet, Airport, Transit, and other teams are prepared to coordinate field work. The department can activate its Department Operations Center to work with DEM and the County EOC during a significant event.
Regional Parks is clearing drainage systems, repairing damaged trails and roads, and checking sites vulnerable to flooding, slides, or erosion. Current work includes culvert and drainage repairs at Hood Mountain and North Sonoma Mountain, access and drainage assessments at Monte Rio Redwoods and Mark West, and work at Foothill, the West County Trail, Sonoma Valley, Calabazas, and Taylor Mountain. Regional Parks is also preparing Russian River facilities for flooding, staging backup power for restroom pumps at Doran Beach, and checking marina docks, utilities, and moorings ahead of winter storms.
Staff will ask the Boards to adopt a concurrent resolution directing a countywide inventory of vulnerable infrastructure and a prioritized record of projects. The resolution would help departments identify work they can complete now, work that needs permits or outside assistance, and protective actions that depend on storm conditions. It would also support coordination on permitting, flood-fighting resources, and preparedness across the operational area. Together, these efforts give the County a clearer picture of where winter storms could cause harm and what each department is doing before conditions worsen.
Strategic Plan:
This item directly supports the County’s Five-Year Strategic Plan and is aligned with the following pillar, goal, and objective.
Pillar: Resilient Infrastructure
Goal: Goal 5: Support, fund, and expand flood protection.
Objective: Objective 3: Evaluate the feasibility, creation, and/or update of Flood Protection Plans and seek out financing mechanisms to establish protection zones countywide by 2026.
Racial Equity:
Was this item identified as an opportunity to apply the Racial Equity Toolkit?
Yes
A racial equity analysis was conducted and the results can be found in Attachment 2.
Prior Board Actions:
10/07/2025: Receive an Update on Flood Preparedness
01/15/2019: Quarterly Disaster Preparedness Workshop - Overview of Flood Hazards
Fiscal Summary
Narrative Explanation of Fiscal Impacts:
None.
Narrative Explanation of Staffing Impacts (If Required):
None.
Attachments:
1. Resolution
2. Racial Equity Analysis
3. PowerPoint Presentation
Related Items “On File” with the Clerk of the Board:
None.