In wake of historic floods, Dunn, Fain lead District in funding response, studying Hanson Dam release impacts

February 10, 2026

After a briefing Tuesday on the response to historic December 2025 flooding, the King County Flood Control District (KCFCD) Board of Supervisors (the Board) approved legislation funding the emergency response and directing a comprehensive study of downstream impacts from water releases at Howard Hanson Dam.

“December’s floods served as a clear reminder that operations at the Howard Hanson Dam have real consequences for downstream communities,” said Flood Control District Board Supervisor Steffanie Fain, who co-sponsored the amendment to add the study with Board Chair Reagan Dunn. “Thanks to decades of flood control investments, no lives were lost, but many homes, businesses, agricultural lands, infrastructure, and our regional economy suffered significant damages. This study responds to calls from our community for transparency and accountability, and it will help inform how we will address future emergencies.”

The amendment was attached to a $10 million package, sponsored by Dunn and passed by the KCFCD Tuesday to address the money spent during the 2025 flood event and fund the urgent and emergent work necessary before the next flood event. It directs the KCFCD’s Executive Director to examine impacts from dam operations during the December 2025 flood event, including rapid drawdowns, increases in the amount and duration of water releases, and potential strategies to mitigate downstream impacts in future flood events. The Executive Director will provide an update on the study’s scope of work and milestones to the District Executive Committee at its March 4, 2026 meeting.

“Now that the most significant flooding event in decades is behind us, it is important that the Flood Control District take decisive action to address damage and learn how we can improve our response,” Dunn said. “This study will give us the facts we need to understand the downstream impacts of dam operations during the December floods and ensure we are better prepared to protect communities in future events.”

The vote came after the Board was briefed by the King County Department of Natural Resources and Parks and the U.S. Army Corps of Engineers on flood operations and interagency coordination during the historic December floods. Additionally, the Board directed the KCFCD to propose options for the 2026 grant programs that prioritize flood response.

The December 2025 flood event was extraordinary and historic, impacting King County and much of the surrounding region. Triggered by a series of powerful atmospheric rivers that dumped heavy rainfall across Western Washington, it caused rivers to swell far beyond flood stage, prompting widespread evacuations and a statewide emergency declaration. Lasting from December 8 through Christmas Day, it required sustained emergency response, field monitoring, and infrastructure protection efforts.