Seattle District begins to wrap-up flood operations

Published Dec. 6, 2021
A construction dump truck and earth mover sit atop the repaired Rainbow Slough levee.

Whatcom County, Wash. (Nov. 27, 2021) - US Army Corps of Engineers closed a breach in the Rainbow Slough Levee caused by flooding from the three successive atmospheric rivers that hit the area from Nov. 12 to Nov. 22.

After multiple atmospheric river weather events through the last half of November, the U.S. Army Corps of Engineers’ flood fighting activity is winding down. During the events, USACE deployed flood teams supplying communities with technical assistance. They also contributed 167,500 sandbags, 1,320 Hesco barriers and 750 super sacks to help needed flood areas.

USACE responded to many direct, technical assistance and flood fight supply requests in a short period of time.  Eight jurisdictions requested USACE direct assistance; 13 requested flood fight supplies; and approximately 24 different organizations requested technical assistance. USACE also deployed a sandbag machine and four water pumps to assist with the flood efforts.

“Overall, USACE had a critical role in supplementing local flood response efforts due to our expertise with repairing levees, ability to contract in a timely manner, and deploy flood response teams who can provide the necessary direct and technical assistance required to mitigate against additional damages across multiple communities,” explained Daryl Downing, flood fight Chief of Operations.

These severe weather events mostly impacted the Skagit and Nooksack River basins.

The district’s Emergency Operations Center continues to be activated and flood teams are supporting the State of Washington and Whatcom County with temporary emergency measures. One team is providing technical assistance to the state of Washington and other partners.

This is a longer than normal effort for Western Washington flooding—going on 27 days so far.

The next steps for Seattle District include inspecting levees for flood damage and assessing plans for future repairs with local officials.

Levees on both the Skagit And Nooksack river systems sustained damage. Multiple levees on the Nooksack River were breached, increasing the flood risk of the communities in the leveed areas. Levees on the Skagit River sustained damages, but none breached.

Engineers in the Corps’ Reservoir Control Center monitored conditions and responded to forecasted flooding. They managed the Ross and Upper Baker dams in the Skagit River basin and Wynoochee dam in the Chehalis River basin when pre-defined flood flow thresholds were exceeded in these basins on two separate weekends.

According to National Oceanic and Atmospheric Administration, atmospheric rivers are long, flowing columns of condensed water vapor. Like a conveyor belt, they carry vapor for thousands of miles from out over the ocean. When these atmospheric rivers hit the West Coast, it generated a series of storms, with each storm producing inches of rain.

Public Law 84-99 enables the USACE to assist state and local authorities in flood fight activities and cost share in the repair of eligible flood protection structures following a flood event and at the request of a local sponsor. The purpose is to prevent loss of life and minimize property damage associated with severe weather.

Dallas Edwards
(206) 764-6958

Release no. 21-016