It will take six to eight weeks to repair a section of the Alaska Highway washed out south of Watson Lake on Canada Day, the federal government says.

After a Monday morning of abject confusion on the part of the British Columbia and federal governments, the highway reopened at about 3:00 that afternoon.

The three-kilometre detour around the problem area is limited to single-lane traffic guided by pilot vehicles.

The massive washout over the Canada Day long weekend closed the vital artery in both directions from last Friday through Monday.

That prompted shortages at several grocery stores in Whitehorse, including the Real Canadian Superstore.

According to various sources, including the Alaska Highway News, “a former section of Highway 97 will be used, with pilot vehicles, to re-route traffic around the problem area.”

The Highway News reported, “On Canada Day, the traffic monitoring service had reported water pooling along a stretch of the Alaska Highway between the Fireside Maintenance Camp and Allend Lookout.

“Just hours later, however, and with long weekend traffic travelling in both directions, the road gave way, destroying a large section of paved highway.”

George Smith is a contract asset performance manager for Public Services and Procurement Canada (PSPC).

He told the Star in an email Tuesday from Fort Nelson, B.C. that engineering consultants were slated to visit the site today to further assess the damage.

Smith said the washout was caused by a beaver dam collapsing. The flood waters from the breach plugged a culvert and tore the highway apart.

Michele LaRose, a colleague of Smith’s, expanded on that in a statement.

“The heavy rainfall that had occurred over the preceding weeks in the area resulted in the collapse of a beaver dam,” she wrote.

“The resulting runoff event carried stones and loose debris which blocked the existing culverts under the highway.

“With the blocked culvert flow, the runoff then backed up, eventually to the point where it overflowed across the road surface. The flow was so high that itcompletely washed out a 75-metre stretch of the highway.

“PSPC notified the highway maintenance contractor who arrived on-site on July 1st. Traffic barriers were put in place and work was started to get a detour in place as soon as possible.

“The detour will remain in place until the work to repair the main section of highway is completed,” LaRose added.

“All efforts will be expended to ensure the repairs are completed as soon as possible. With an average of 800 to 1,200 daily travellers on the Alaska Highway, PSPC will ensure that the public is aware of closures and the impacts on local traffic through public notices that will be issued in advance and shared through our social media channels.

“In the meantime, people travelling are advised to obey traffic signs and follow the pilot car on the assigned detour route,’ LaRose said.

The detour work was conducted by contractors from the Lower Post First Nation and highway maintenance contractors.

The closure and panic-buying in Whitehorse grocery stores, resulting in some shelves being bare of produce and dairy products, rekindled memories of June 2012.

At that time, a major Alaska Highway washout near Rancheria saw local stores quickly sold out of perishables and toilet paper due to supply truck deliveries from the south being cut off.