By Steven Schauer, Deputy Executive Director
In December 2025, King County experienced a historic flood event due to its scale, intensity, and duration. The King County Flood Control District’s Board of Supervisors has been receiving regular briefings on response and recovery efforts. On March 4, 2026, the Board’s Executive Committee received a second post-flood status update. The first update was provided on February 10, 2025 and is highlighted in our blog post from February 19th (December 2025 Flood Event: A Historic Test of Preparation, Partnership, and Public Service).
The March 4th presentation was provided by Laura Bradstreet, Environmental Programs Section Manager in the River and Floodplain Management Section of the King County Department of Natural Resources and Parks. Bradstreet’s presentation highlighted the extraordinary efforts underway since the floodwaters first rose in December and outlined the work still ahead as the County evaluates damage and prioritizes repairs.
A Historic Flood Event
The December 2025 flood was unusual in both scale and duration, triggering an extended emergency response across the county. Staff began round-the-clock operations on December 8, with flood patrol teams and the Flood Warning Center working tirelessly to monitor river conditions and protect communities.
Key response statistics shared during the briefing include:
- 1,900 miles of flood patrol coverage
- 952 hours logged by flood patrol teams
- 482 hours logged by Flood Warning Center personnel
- The longest activation of the Flood Warning Center in at least 40 years
- Six river systems reached severe flood conditions (Phase 4 flooding)
The Flood Warning Center remained active through December 30, after which staff transitioned from emergency flood fighting to longer-term recovery and response efforts.
Emergency Repairs and Immediate Actions
During and immediately after the flood, crews moved quickly to stabilize flood protection facilities and address urgent risks.
With authorization from the King County Flood Control District’s Board in February, teams carried out 16 emergency repairs, many of which continued through January and February, with the final repair concluding in early March.
These emergency actions were critical to ensuring that damaged levees and revetments could withstand additional storms during the winter flood season.
A Massive Post-Flood Inspection Effort
Once immediate flood response operations ended, county staff launched a comprehensive inspection effort to evaluate damage across the river system.
Inspection teams began work the day after the Flood Warning Center closed. Specialists examined levees and revetments for signs of damage such as:
- Sinkholes
- Scouring or erosion
- Missing riprap
- Ground cracking
- Slumping along riverbanks
In total, the effort involved:
- 46 inspection teams
- 386 post-flood inspection reports
- Approximately 3,500 photographs documenting conditions
The inspections revealed that 163 flood protection facilities – about 32% of the County’s levees and revetments – sustained damage during the flood.
Damage was widespread across multiple river basins, highlighting the severity of the event.
Estimating the Cost of Damage
Using historical project data, engineers developed cost estimates to repair damaged facilities by replacing what was previously in place. Based on those estimates:
- The total countywide damage estimate is approximately $71.1 million
- About $47 million (66%) of that damage is associated with the River and Floodplain Management Program’s flood protection facilities
Bradstreet noted that these estimates include construction costs only, and do not yet account for planning, design, environmental mitigation, community collaboration, or property acquisition; factors that are typically part of major flood risk reduction projects.
She also emphasized that the situation could have been far worse if not for the dozens of flood risk reduction and habitat restoration projects funded by the King County Flood Control District over the past 18 years, which have strengthened river systems and reduced risk to communities.
How Damage Is Being Prioritized
Following the inspections, technical teams held intensive workshops to evaluate each damaged site using criteria such as:
- Risk to people and property
- Severity of damage
- Urgency of repair
- Consequences if another flood occurs
Each site was assigned a risk score to help determine the most appropriate response.
Damage sites were then sorted into several categories, including:
- Urgent repairs needed before the next flood season
- New capital improvement projects (CIP) not currently in the work program
- Repairs already included in the six-year CIP
- Planning or capital investment strategy projects for lower-risk sites
- Facility decommissioning opportunities, where flood infrastructure protecting undeveloped areas may be removed and restored to more natural river conditions
- Maintenance or monitoring actions for minor damage
These categories will help guide decision-making as the County and King County Flood Control District determine how best to allocate resources and address damage across the county.
Next Steps: Basin-Wide Prioritization
The next phase of work involves cross-basin prioritization, where staff evaluate flood damage alongside projects that were already scheduled in the King County Flood Control District’s capital program.
This process will help answer a critical question: how to integrate new post-flood repair needs with existing flood risk reduction priorities across the region?
King County Flood Control District staff, together with county staff, will oversee the prioritization process, which will be presented, with options and recommendations, to the King County Flood Control District Board. The Board will ultimately determine how to adapt the work program moving forward.
Dedicated Teams Working for King County
Bradstreet concluded her briefing by recognizing the extraordinary dedication of the staff responding to the flood. Since early December, teams across King County have been working tirelessly to patrol rivers, conduct inspections, stabilize damaged infrastructure, and evaluate future repair needs, all in service of protecting communities from flood risk.
As she noted during the briefing, while the floodwaters may have receded, the work is far from over.
Continuing Updates
The King County Flood Control District’s Board of Supervisors will continue receiving regular updates as recovery and evaluation efforts move forward. Future post-flood briefings will continue to be shared with the Board and summarized on the King County Flood Control District’s blog, ensuring that King County residents remain informed about the work underway to repair damaged facilities, strengthen flood protection systems, and prepare for future flood events.