Officials in Washington state ordered immediate evacuations in three south Seattle suburbs on Monday after a levee failed following a week of heavy rains.
The evacuation order from King county covered homes and businesses east of the Green River in parts of Kent, Auburn and Tukwila.
The National Weather Service (NWS) issued a flash flood warning covering nearly 47,000 people. In their message, NWS warned that the failure could lead to “life threatening flash-flooding” on the east side of the levee.
The Desimone levee, located about 5 miles (8km) south of downtown Seattle, breached following a week of record-level flood waters that triggered widespread evacuations.
The levee was significantly damaged from flooding back in 2020, and long-term repairs are not anticipated to be completed until 2031. King county crews are installing an emergency measure to help stabilize the levee now and minimize flooding risk for the community, which will remain in place until the long-term repairs are complete.
King county’s director of emergency management Brendan McCluskey told the Seattle Times that the repairs could take several hours, and that officials were closely monitoring the Desimone levee.
A car-sized chunk of the levee was washed away by flood water. Images showed workers using heavy equipment to drop large sandbags into the hole, working to keep it from growing.
The Washington national guard said that it was sending troops to King county. The guard has already been helping flood-affected residents in the western part of the state over the weekend. Authorities have been concerned about levee breaches for days around the state amid the torrential downpours.
An extraordinarily strong system known as an atmospheric river dropped more than a foot of rain, flooding rivers that stretch across the state toward Canada to dangerous levels. Mudslides tore through communities, washing away homes and stranding families on rooftops as they waited for rescue.
Atmospheric rivers are large systems that transport water vapor from the tropics and are essential to the world’s annual water supplies. While not uncommon in the Pacific north-west, these severe water events can lead to dangerous floods and mudslides, as is currently the case.
Researchers have seen water vapor increasingly transported to the west coast over the past 70 years, according to studies conducted by the US Geological Survey. This increase in water vapor has been directly associated with the warming of the ocean’s surface linked to climate change.
In Sumas, Washington, the US Coast Guard deployed two helicopter crews to rescue people from their homes where the water had already risen to the second floor, effectively trapping them.
