BELLINGHAM — A landslide brought the northbound side of Interstate 5 to a halt around 5 a.m. Sunday near Iowa Street in Bellingham. The freeway reopened that afternoon after the Washington State Department of Transportation was able to clear the road.
The city of Bellingham issued a statement Monday explaining the incident was likely caused by someone leaving items in a culvert.
“Preliminary investigations indicate that a clogged culvert, blocked by a roll of carpet padding from an unknown location, prevented water from flowing through the storm drainage system,” according to the statement from the Public Works Department. “This led to water buildup, which saturated the soil and ultimately destabilized the slope. City engineers reviewed the safety of surrounding structures, including houses on Maryland Street, and there is no indication of immediate risk.”
The statement also urges residents to help prevent future flooding by regularly checking and clearing nearby storm drains and ditches of any debris, if possible and safe to do so. Clogged drains that are not safe can be reported to Public Works at cob.org/fix, through the SeeClickFix app or by calling 360-778-7700.
The Bellingham Herald reached out to WSDOT for more information about the colossal closure and cleanup. Here’s what you need to know about the mudslide and its aftermath.
Freeway closure lasted 10 hours
The entire northbound side of the freeway was closed as crews worked to clear the debris, according to RB McKeon, communications manager for WSDOT’s northwest division. The closure lasted 10 hours, from roughly 5 a.m. to 3 p.m. The damage spilled over to the southbound side of the freeway as well — its left lane was closed for six hours.
According to McKeon, the landslide took a heavier toll on southbound traffic, which saw backups of roughly 3 miles. The northbound side of the freeway, meanwhile, saw backups of roughly a mile.
2,000 cubic yards of debris on I-5
During the 10-hour cleanup, WSDOT estimates its crews removed 2,000 cubic yards — roughly 54,000 cubic feet — of debris from the freeway. The debris was primarily made up of mud but also included hillside vegetation.
WSDOT didn’t track the weight of the debris that was cleared, and it’s difficult to calculate since the density of debris varies depending on materials in it. But that doesn’t mean we can’t get a general idea of how much debris was cleared. Clay soil typically weighs around 1.5 grams per cubic centimeter. That translates to roughly 2,500 pounds for each cubic yard — and that’s before taking into account the amount of water absorbed by the soil in a landslide — meaning the debris that the department cleared likely weighed in the thousands of tons.
How WSDOT cleared the I-5 debris
So how did WSDOT clear so much debris and have the freeway reopened by the afternoon?
According to McKeon, it was the result of an effort that involved state and local government agencies.
“Crews arrived on scene, assessed the area and got to work, bringing in heavy machinery to load it into trucks and haul away the debris. … Our crews are trained to respond to these incidents in a safe and efficient manner. We worked with partners like the City of Bellingham and Washington State Patrol to close the road and then assess the situation. Our crews train on the types of heavy machinery and were ready to begin clearing the road,” McKeon said.
Crews were met with an additional roadblock as well — a passenger car and a semi truck got stuck in the mud. The Bellingham Fire Department dug the car out of the mud. Removing the truck required a few additional steps. WSDOT was able to unhitch the cab from the trailer, and a private towing company was able to tow it away.
While the freeway reopened around 3 p.m. Sunday, McKeon said that WSDOT’s work on the site isn’t quite done. The department’s geotechs are monitoring the area, and plan to return to the site this week for additional assessments.
