Washington state warned that river water levels were rising rapidly due to prolonged heavy rain, threatening to cause flooding that was forecast to be “catastrophic”.
A weather pattern with high humidity from the Pacific Ocean pouring into the Northwest US this week causes heavy rain, causing many rivers in Washington state to risk rising close to or exceeding record levels, especially the Skagit and Snohomish rivers.
Governor Bob Ferguson declared a state of emergency across the state, warning that lives would be at risk in the coming days, and estimating that up to 100,000 residents may have to evacuate. He said forecast models of the National Oceanic and Atmospheric Administration (NOAA) recorded 18 major floods and 15 moderate floods that could occur, with many locations forecast to reach record flood levels.
The US National Weather Service also forecasts the risk of floods at a catastrophic level, and warns of landslides in steep terrain areas. “We forecast that water levels in many rivers will reach historic levels at 4:00 a.m. on December 11. This situation may last until the next morning,” Mr. Ferguson said.
Floods poured on the Skykomish River on December 10, in Snohomish County. Image: AP
In the town of Mount Vernon, officials asked people living in low-lying areas along the river to evacuate immediately. People drove cars to form long lines at sandbag distribution points to reinforce houses.
The Washington National Guard deployed hundreds of soldiers to support search and rescue. In Orting, Pierce County, police rescued many people in a mobile home park when the water rose to their waists. Part of the town was ordered to evacuate due to concerns that the Puyallup River exceeded safe levels and caused a levee breach.
Many arterial roads were blocked. On I-90, landslides left vehicles stuck in the mud. The US-2 route in the mountains also had to be closed due to rocks and mud falling, with no alternative detour.
The threat from the Skagit River is threatening the town of Concrete and the city of Mount Vernon with about 35,000 people. Skagit County officials said the river will overflow its banks with record water levels in both localities on December 11-12. Although the city of Mount Vernon built flood protection dikes in 2018, officials fear this flood peak is the most dangerous in many years.
Residents of Sultan town, Snohomish County, put sandbags to block water from entering the local post office on the night of December 10. Image: AP
State officials went door-to-door to warn people about the impending flood risk in some areas, and evacuated a mobile home park along the Snohomish River. The city of Snohomish declared a state of emergency, while crews in Auburn, south of Seattle, erected temporary barriers to control flooding along the White River.
In Sumas, a small town close to the US-Canada border, flood alarms sounded at city hall and people were asked to leave. The border clearance point also closed one way from Canada to the United States to facilitate evacuation operations, according to the Abbotsford Police Department.