An emergency alert advising Sumas and Everson residents to voluntarily evacuate Saturday night, Nov. 27, was sent out shortly before 6 p.m. as rain continued to fall in Whatcom County.
"Life safety is our primary concern. Road closures begin as early as 4 a.m. Sunday," the flooding alert read.
Flooding impacts could include levee overtopping at Main Street in Everson Sunday morning, Nov. 28, according to Whatcom County's website. Water may then move downstream to Sumas and across the border to Canada, it stated.
The Red Cross shelter is open at 1775 Front St. in Lynden.
The National Weather Service report Saturday afternoon said heavy rainfall in the Olympics and Cascades will force sharp rises on rivers with flooding possible. Its flood watch was in effect through Monday morning, Nov. 29. The weather service said between 1 inch and 2 inches of rain was possible Saturday, and up to another inch of rain Sunday, in northern Whatcom County.
As of midday, the Nooksack River was still predicted to crest in the moderate flood range, according to Whatcom County's website. "There is uncertainty with how changes to the river channel and damages to the levee system may impact the flooding that results from this storm. Comparing data from past storms to what is predicted, the upcoming storm system appears similar to what occurred during the 2020 'Superbowl Flood'," the update stated.
"Flows on the north side of the river near Lynden will be higher than typically experienced during a flood of this magnitude because of a levee breach upstream of Hannegan Road," it stated.
The U.S. Army Corps of Engineers was working to repair levee systems Saturday, including the levee upstream from the Everson Bridge and a levee breach near Ferndale.
"However, even with repairs, the levee system has been stressed and could be vulnerable in the next storm event," the county stated.
Whatcom County Sheriff's Office Search and Rescue, along with U.S. Border Patrol Search and Rescue, local fire district personnel, and approximately 30 members of the Washington State National Guard, are at work in response, the website stated. "The Guard is staging to assist local agencies with sandbagging, transportation of supplies, and providing support to Nooksack, Sumas, and Everson. In addition to preparing and distributing sandbags, responders are monitoring and barricading flooded roads and staging for water rescues if needed. Border Patrol units will be working to keep traffic off flooded or flood-damaged county roads."
The areas that are now likely to flood were inundated as the Nooksack River surged over its banks on Nov. 14.
Damages from that flooding could reach as high as $50 million, Whatcom County officials said at an online briefing Nov. 23.
John Gargett, deputy director of the Whatcom County Sheriff's Office Division of Emergency Management, said he wouldn't be surprised if public and private damages and economic losses reach that mark.
Included among that $50 million, Gargett said, were estimates of $15 to $20 million in damage to houses in the area, "tens of millions of dollars" in damage to public infrastructure and another $15 to $20 million in damage to area business centers.