Snohomish County Executive Dave Somers has issued an emergency proclamation regarding the flooding throughout much of the county during the recent atmospheric river, heavy rainfall event.
The emergency proclamation allows the County to spend public funds and take prudent actions to ensure the safety of residents and waives some administrative requirements to expedite response efforts. It also directs county departments to take measures to mitigate and prevent impacts upon private property and publicly owned infrastructure.
In his emergency proclamation, Executive Dave Somers noted, “Many families, businesses, and communities have been impacted by the floods this week and more rain continues to fall. Therefore, I’ve declared an emergency to ensure we have every tool available to us. For cities and other agencies who have responded to the flooding, please know that we will be there to assist in any way we can. We’ll get through this together.”
During the significant rain event in the county that began in earnest Sunday evening December 3rd, rain amounts in the lowlands ranged from 2 to 4 inches through Wednesday morning, December 6th. Precipitation amounts were higher in the Cascades and foothills. Foothill locations received between 4 to 7 inches of rainfall and in the Cascades, 7 to 10 inches.
During the preceding weekend, several feet of long-awaited snow fell in the Cascades. Not all of that fresh snow melted and run off into the swollen rivers, despite the myth that was the case. Stevens Pass on Sunday had 38 inches of snow and on Wednesday, snow on the ground had dropped to 19 inches. At White Chuck near 5000 feet in the upper Stillaguamish River basin, 45 inches of snow was on the ground Sunday and by Wednesday morning, 26 inches remained.
The heavy amount of rainfall in the foothills and lowlands is what drove the rapid rise of rivers. The Stillaguamish River at Arlington crested at a new all-time record high of 21.34 feet, just above the former record of 21.16 feet set on December 12, 2010.
The Snoqualmie, Skykomish, Snohomish and other North Sound rivers also rose well above flood stage, flooding farmland, neighborhoods, and many low-lying roadways including SR 530, adversely impacting transportation and emergency services. At one point Tuesday, Silvana was surrounding by flood waters.
“Our partners across the county have had a busy few days, with over a dozen water rescues so far and roads and utilities crews working around the clock,” said Lucia Schmit, director of the Snohomish County Department of Emergency Management. “This declaration will help get those agencies the resources they need to continue to keep our residents safe.”
The County will continue to work alongside partners in cities, schools, and emergency services to monitor the weather and rivers, and provide information and resources as needed.
The atmospheric river has dissipated and moved southeast away from the North Sound. The copious amounts of rain have eased as a cooler more showery weather pattern has developed with snow levels in the mountains back down to the passes.
This change in the weather has allowed rivers to recede with no forecast threat of renewed flooding. For areas with lingering standing water, it will take a few more days for that water to recede. Unfortunately with now saturated soils, the threat of local landslides on steep slopes will likely remain through the weekend.
The flooding event serves as yet another reminder for those who live or drive through flood prone areas. Evacuation is safer to do before flood waters cover roadways. Remember – turn around, don’t drown. As little as 6 inches of moving water can displace smaller vehicles, and a foot or two of water can float away many other vehicles including pickup trucks and SUVs. Motorists are encouraged to avoid flooded roads and obey road closure signs.