Devastating floods in British Columbia have scrambled supply chains across western Canada, leaving truck drivers stranded, grocery store shelves stripped of food and access to the country’s largest port blocked.

It’s a crisis that could affect both Canada and the United States, where supply lines have already been strained by the pandemic.

An atmospheric river earlier this week produced what officials described as a once-in-a-century rainfall, causing flooding and powerful mudslides in the southern part of British Columbia, Canada’s westernmost province.

The impact on infrastructure was catastrophic, collapsing highways, submerging railroad tracks and forcing a regional oil pipeline to close. The deluge and accompanying mudslides also choked off the city of Vancouver, shuttering four main roads and two key rail lines linking to its port.

The Port of Vancouver — the third largest in North America — enables the trade of about $240 billion in goods per year, connecting Canada to 170 trading economies. Some of the affected routes bring goods from the port to places such as Ontario, Quebec and the Chicago area.

British Columbia authorities on Wednesday declared a state of emergency and urged residents not to hoard food or fuel as panic grew over potential shortages.

Supermarket chain Save-On-Foods called on customers not to clear out shelves.

“We understand that these are very uncertain times, and stressful times, and are asking our customers to maintain normal shopping habits,” chief executive Darrell Jones said in a video posted on Twitter.

The federal government said that it would send troops to help evacuate people and restore the movement of supplies to the region. And federal officials promised Thursday to help the beleaguered province rebuild its infrastructure.

“The message for today is: Conserve fuel wisely and other materials because there are interruptions in the supply chain for a number of things that are essential,” Rob Fleming, the provincial minister of transportation and infrastructure, said at a news conference Thursday.

The damage to roads and rail lines has prompted one railway system to help airlift people and goods via helicopter, Fleming said Wednesday, and a regional ferry company was testing new cargo routes.

But for trucks traveling east or west across Canada, the journey is nearly impossible. The best option for the drivers is to go south through the United States and back across the Canadian border, according to Dave Earle, chief executive of the BC Trucking Association.

Still, crossing the U.S. border requires added paperwork, exacerbating delays, Earle said.

Marco Mendicino, Canada’s public safety minister, told reporters Friday that interim measures were being set up with the United States to help move commercial good more easily.

“These interim measures are largely intended for Canadian domestic truck carriers that do not normally cross the border in the course of their business,” he said at a news conference in Ottawa. “Any Canadian carriers that operate between the United States and Canada … are encouraged to follow the standard procedures.”

The crisis could also ripple across parts of the United States, which is reeling from its own supply chain issues caused in large part by the coronavirus pandemic.

Manufacturing hiccups coupled with consumer demand have together caused shortages of an array of items and sent prices soaring around the globe.

“We have already a perfect storm on the global supply chain. Added to that, now we have disruption that is caused by weather,” said Adel Guitouni, a business professor at the University of Victoria.

British Columbia Premier John Horgan said Wednesday on Twitter that the storm was a reminder of the urgency needed to address climate change.

“While [Canada’s environment agency] called this a 1-in-100 year event, we know the increased likelihood of intense storms is due to the climate crisis,” he said. “We need to keep doing more to mitigate its impacts and build the cleaner future people and our planet need.”

Amanda Coletta in Toronto contributed to this report.

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