The Desimone Levee in Tukwila failed after several days of heavy rain, prompting a flash flood warning and mandatory evacuations for parts of King County, affecting about 46,000 people. The National Weather Service warned floodwaters were moving toward Interstate 405 and urged immediate evacuation. The Washington National Guard is deploying personnel to assist local responders. Meteorologists said a string of atmospheric river storms delivered up to 20 inches of rain to parts of the Pacific Northwest.
Levee Breach Near Seattle Sparks Flash Flood Warning, Evacuations for 46,000
Crews work to repair a failed levee along the Green River, after multiple atmospheric rivers brought rain and flooding to the Pacific Northwest, in Tukwila, Washington, U.S., December 15, 2025. REUTERS/David Ryder
Dec. 15 (Reuters) — A breach of the Desimone Levee in Tukwila, Washington, after several days of heavy rain has prompted a flash flood warning and evacuation orders for a large portion of King County, authorities said on Monday.
The National Weather Service said it issued the flash flood warning after the levee failed along the Green River, about five miles south of downtown Seattle, and warned that floodwaters were likely moving toward Interstate 405, a major transportation artery. The evacuation notice covers an area home to roughly 46,000 residents.
A gas pump at a flooded gas station near the Green River, after multiple atmospheric rivers brought rain and flooding to the Pacific Northwest, in Auburn, Washington, U.S., December 15, 2025. REUTERS/David Ryder
"Leave immediately if you are in this area," the National Weather Service posted on social media. "Conditions are dangerous and access routes may be lost at any time."
The Washington National Guard said it was deploying personnel to assist King County. Guard members had already been helping residents affected by flooding across western Washington over the weekend.
Officials had been warning for days about possible levee failures as torrential downpours — driven by a series of atmospheric river storms that funneled ocean moisture inland — struck the Pacific Northwest. Some areas recorded as much as 20 inches of rain over the course of a week, increasing pressure on river systems and flood defenses.
Workers respond to flooding at a gas station near the Green River, after multiple atmospheric rivers brought rain and flooding to the Pacific Northwest, in Auburn, Washington, U.S., December 15, 2025. REUTERS/David Ryder
Local authorities urged residents in the evacuation zone to move to higher ground immediately, avoid driving through flooded areas, and follow official updates from emergency management and the National Weather Service as crews monitor water levels and road conditions.
