Repairs to a section of the Alaska Highway in British Columbia near the Yukon border are expected to take more than a month before the road can reopen fully again, according to Canadian authorities.
The highway reopened with a detour Monday after a large chunk of roadway north of Liard Hot Springs in British Columbia washed away Friday, leaving a crevasse that for several days closed the main route between Alaska and the Lower 48.
The flooding was caused by a collapsed beaver dam, according to Public Services and Procurement Canada. The agency said the damage was caused by heavy rainfall in the area over the past few weeks, which caused the dam to collapse.
“The resulting runoff event carried stones and loose debris which blocked the existing culverts under the highway,” the agency said in an email Tuesday. With the culvert flow blocked, runoff backed up and eventually flowed across the surface of the road.
The flow was so high it “completely washed out” a roughly 246-foot section of the highway, officials said.
That portion of highway remained closed until Monday, when crews were able to establish a one-lane detour route allowing alternating traffic through the area. A pilot car is guiding motorists through the detour.
According to Public Services and Procurement Canada, the detour will stay in place until work to repair the highway is complete. That’s expected to take six to eight weeks.
The 1,387-mile Alaska Highway — also known as the Alcan — is the main route by which trucks hauling freight, visitors and residents travel between Alaska and the Lower 48. An average of 800 to 1,200 people travel the highway each day, according to the Canadian public services agency.
A road closure caused by flooding from a collapsed beaver dam also vexed Alaska drivers last year, when a flash flood of water and debris overflowed onto the Richardson Highway near Paxson.