Posted on January 7, 2026
In early December 2025, western Washington was struck by a series of powerful atmospheric rivers, bringing historic rainfall, over 10 inches in some areas, that resulted in catastrophic flooding, landslides, and widespread infrastructure damage. The hardest-hit regions were low-lying areas such as Whatcom, Skagit, Snohomish and King counties, where major rivers like the Skagit, Green and White overflowed, triggering extensive evacuations. The severity of the flooding was compounded by saturated soils and unusually warm Pacific moisture that further intensified the impacts of the storm series, which led to a state of emergency and 24-hour operations by the U.S. Army Corps of Engineers (USACE), Seattle District.
Early Response and Preparedness
Before the first storm made landfall, USACE Seattle District’s Emergency Operations Center (EOC) and Reservoir Control Center (RCC) began monitoring weather patterns and river levels. On December 3, as multiple atmospheric rivers were forecasted to impact the region, the EOC was activated.
A few days later, as the storm series intensified, the RCC activated and the EOC further increased its activation level to support continuous operations. USACE teams focused on managing water releases from key dams to mitigate flood risks and flood patrols were deployed to monitor riverbanks and low-lying areas.
Dam Operations and Risk Management Efforts
With record flooding in the area, the RCC’s top priority was the careful regulation of water levels at Howard A. Hanson and Mud Mountain Dams, both USACE operating projects, and the Upper Baker (owned by Puget Sound Energy), Ross (owned by Seattle City Light), and Wynoochee (owned by Tacoma Public Utilities) Dams, which the Seattle District’s RCC takes control of under flood conditions. These dams saw deliberate adjustments to control the outflows and to reduce downstream flooding risks. As river levels remained high due to continued precipitation, USACE engineers closely monitored conditions to prevent damage to flood protection infrastructure.
“Reducing risk to the public by emptying reservoir pools as quickly and safely as possible was critical,” said Travis Ball, Seattle District chief of hydraulic and coastal engineering. “As inflows increased with incoming storms, our teams worked tirelessly to manage these releases in the safest manner possible.”
USACE Emergency Management Mission
Under USACE’s emergency management mission, the Seattle District played a critical role in coordinating and executing flood response efforts in support of other government partners. USACE’s mission includes providing engineering solutions to reduce risks and minimize damage from natural disasters like floods. Their emergency management efforts are essential in safeguarding lives, infrastructure, and communities. USACE works closely with local, county, state, and federal partners, including FEMA, local emergency operations centers, and state agencies, to ensure a unified response during crises.
During flood events, government partners can request technical or direct assistance support from USACE. This support allows community leaders to quickly access flood supplies to mitigate flood risk in areas of concern, leverage Army Corps expertise in the form of recommendations or data to help solve complex flooding challenges, and request emergency contracting from the Army Corps to execute work such as emergency levee repairs.
Direct Assistance Requests and Flood Mitigation Support As part of flood response efforts, USACE provided direct assistance to various local and state agencies by addressing specific needs related to flood protection infrastructure. Direct assistance involves the use of emergency contracting to procure equipment and/or materials to help communities manage flood risks and protect critical infrastructure, or to execute emergency work to provide temporary flood protection. To date, USACE successfully completed all16 direct assistance requests for this event, including: Snohomish County Diking District #1 Ebey Island Levee; Grays Harbor Juvenile Detention Center; Skagit County Diking District #22 Levee; Skagit County Diking District #3 Levee; Mount Baker Rim Levee; Glacier Creek Levee; Twin View Levee; Cockreham Island Levee; Hovander Levee; Sande-Williams Levee; Cannery Levee; Startup Training Levee; and equipment for the City of Pacific, all located in Washington; as well as, Callahan Creek, Montana; Keeler Creek, Montana; and Lightning Creek, Idaho.
“In addition to these construction-based requests, Seattle District delivered 265,000 sandbags, two sandbag machines, nine pumps, 12,700 linear feet of gabion baskets, and more than 4,520 super sacks, to communities in need of additional support,” said Krystle Walker, Seattle District chief of emergency management. “These supplies and equipment were critical in stabilizing flood-prone areas and mitigating further damage to communities.”
Collaboration with Local, State, and Federal Partners
USACE worked hand-in-hand with local, state, and federal agencies to coordinate response efforts. USACE liaisons were stationed at the Washington State Emergency Operations Center (SEOC) and King County, Skagit County and Lincoln County EOCs, where they provided valuable communication support and technical expertise. USACE’s emergency management mission underscores the importance of collaboration at all levels of government. By working with city, county, state, and federal officials, USACE was able to provide seamless support for flood response efforts across affected regions.
“We were committed to maintaining strong relationships with our local and state partners to ensure our response efforts were coordinated effectively,” said Walker. “The partnership and clear communication between USACE, State Emergency Management Departments, FEMA, local agencies, and community leaders was a key element in driving these response efforts forward.”
Ensuring Clear Communication
The Seattle District Public Affairs team prioritized unified communication, ensuring alignment across local, state, and federal partners. This approach was crucial in conveying key information regarding USACE operations, flood risks, and safety measures to the public. By responding to media inquiries, providing timely updates on public-facing websites, and amplifying critical messages, the team worked closely with State EOC Public Information Officers and other government partners to ensure the accurate dissemination of information related to dam releases and the Army Corps’ flood protection efforts. Consistent and coordinated communication was essential for educating the public on USACE operations and flood mitigation measures.
Looking Ahead: Weather Conditions and Continued Operations While the region is currently experiencing a relatively dry period, USACE teams continue to monitor weather conditions closely.
“Even as we transition to recovery operations, we remain vigilant and prepared to respond to new weather threats,” said Walker. “We are committed to ensuring that we are ready to protect communities and infrastructure throughout the region.”
As recovery efforts progress, USACE remains committed to supporting communities in Washington, Montana, and Idaho, ensuring that both public safety and infrastructure integrity remains safeguarded as the region recovers from one of the most challenging flood events in recent memory.
