By Steven Schauer, Deputy Executive Director, and King County Staff

This blog is the second in a three-part series highlighting the emergency repair projects funded through the supplemental budget amendment passed on February 10, 2026.

Response to Historic Flooding

The historic flooding that struck King County between December 8 and December 30, 2025, will be remembered as one of the most significant flood events in the region’s history. Record-setting river flows, prolonged high water, and widespread flooding tested flood protection infrastructure, emergency response systems, and communities across the county.

It’s important to note that despite the severity of the storm, there was no loss of life from flooding in King County. That outcome reflects the dedication of emergency responders, local governments, residents, and decades of flood risk reduction investments made by the King County Flood Control District.

Since its creation in 2007, the King County Flood Control District has invested more than $623 million in flood risk reduction projects throughout King County. Those investments have funded 123 projects designed to protect people, homes, businesses, roads, farmland, and critical infrastructure from flooding. The December 2025 flood demonstrated just how important those investments have been.

The flood damaged nearly 170 flood protection facilities across King County, underscoring the importance of maintaining and improving the more than 500 flood risk reduction facilities that help protect our communities.

In response to the widespread damage, the King County Flood Control District’s Board of Supervisors approved a supplemental budget amendment on February 10, 2026, allocating to King County nearly $3 million for emergency repairs completed during the flood event. Seven emergency projects on the Green River were funded through that allocation, totaling approximately $248,000. These projects addressed immediate threats to levees, pump stations, transportation infrastructure, homes, businesses, and public safety.

Protecting the Desimone Levee

One of the most significant emergency actions occurred at the Desimone Levee near River Mile 15.

As forecasts indicated the potential for record flooding, King County crews proactively implemented a contingency plan to strengthen the levee before floodwaters arrived. A seepage blanket made of granular soil and geotextile fabric was installed on the landward side of the levee to help counteract seepage forces that can weaken flood risk reduction facilities during extreme river conditions.

Despite those preventative measures, a levee breach occurred during the flood event less than half a mile upstream from where crews were conducting contingency work. Emergency responders immediately mobilized installing supersacks and rock to stop the breach and prevent additional damage.

Addressing Levee Damage and Seepage Concerns

Across the Green River Valley, King County Flood Patrol teams and engineers, together with staff from other government partners, identified numerous locations where extreme river conditions caused seepage, sinkholes, and other signs of distress within levees.

At the Briscoe School Levee, crews observed sinkholes and voids on the riverward side of the levee. Immediate repairs helped stabilize the facility and reduce the risk of further deterioration.

At the Pipeline and Okimoto levees near River Mile 22, seepage was observed while the river approached bankfull conditions. These levees help protect a densely developed residential area that includes apartment complexes and other housing. Emergency repairs were undertaken to address the seepage and strengthen the facilities.

Similarly, seepage was observed at the Somes Dolan Levee after floodwaters overtopped portions of the Green River Trail and engaged the riverward side of the levee. The levee helps protect nearby wetlands and residential developments, including condominium communities. Emergency stabilization efforts were completed to address the immediate threat.

At the Tukwila 205 Levee, King County Flood Patrol teams discovered sinkholes forming along the top and landward slope of the levee. King County and the City of Tukwila worked together to implement temporary repairs during the flood event, followed by additional stabilization efforts as floodwaters receded.

Keeping Critical Infrastructure Operating

Flood response is not only about levees and riverbanks; it is also about ensuring critical flood management infrastructure remains operational when it is needed most.

At the P-17 Pump Station, emergency funding supported the installation of a replacement pump and associated plumbing improvements. The project also included assessment and repair work on a second pump to help ensure the facility could continue managing stormwater and flood conditions during future high-water events.

Investing in Resilience

The seven Green River emergency projects funded through the King County Flood Control District’s supplemental budget amendment demonstrate the importance of preparedness, rapid response, and ongoing investment in flood risk reduction infrastructure.

When floodwaters rose to historic levels, emergency crews, Flood Patrol teams, engineers, contractors, and partner agencies worked around the clock to protect communities and critical infrastructure throughout the Green River Valley. Their efforts helped prevent additional damage and strengthened facilities before subsequent storms could create new risks.

Many of these locations later received additional repairs as part of the broader countywide flood recovery effort. Those post-flood projects will be highlighted in a future blog series focused on the work undertaken after the floodwaters receded.

This blog is the second in a three-part series highlighting emergency projects funded through the King County Flood Control District’s February 2026 supplemental budget amendment. Be sure to return for the final installment, which will explore the emergency flood repair projects funded on the White River and how those investments helped protect communities following one of the most significant flood events in King County history.