The Yukon government is going to try again this winter to help Mother Nature build an ice bridge across the Yukon River at Dawson City.
The Department of Highways and Public Works has awarded a $199,700 contract to Whitehorse-based Cobalt Construction to install a log boom across a 100-metre stretch of open water in the river. The idea is to allow ice to accumulate and solidify enough to support vehicles.
Success will depend on the weather, says Brian Crist of Highways and Public Works.
“You can’t really build an ice bridge if the temperatures are above –20 [C], so we’re hoping for temperatures to go down below –20; ideally, –25 or –30 would be perfect,” Crist said.
The territorial government typically builds and maintains an ice crossing at Dawson City every winter to allow residents of West Dawson to access the main town site easily. Until recently, the river has frozen over with no help required.
But the last two winters have seen a persistent stretch of open water where the crossing would normally be. An attempt last year to help the ice build by spraying water was a failure.
Crist says there is no plan to spray again this year, but that could change depending on how the boom works out.
The contractors will likely begin some initial work this week in Dawson. If all goes well, and the weather co-operates, there could be a functional bridge in place by mid-January, Crist said.
Caused by climate change?
It’s not clear what has changed in the last few years to prevent a natural freeze-over. A report done earlier this year by the National Research Council said climate change could be a factor, as well as changes to the riverbed contours.
“At this point, we’re just going year to year, and I believe the goal is to try to gain expertise in these changing times,” Crist said. “We are just trying to come up to speed and to do the best we can to deal with those changes.”
Dawson Mayor Wayne Potoroka says he’s pleased with the plan for this year, and he hopes it works.
But Potoroka says he’d like to see some long-term planning.
“What is this going to look like for years going forward? This sort of hand-wringing, over whether the river would freeze in front of town or not, wasn’t a discussion people were having some years ago,” Potoroka said.
“But it seems to be something that every year comes up again and again.”
Related stories from around the North:
Canada: Canadian government pledges $400 million for northern transport, CBC News
Finland: Arctic Finnish firm wins US award for road maintenance technology, YLE News
Norway: Thawing permafrost melts ground under homes and around Global Seed Vault in Svalbard, The Independent Barents Observer
Russia: Arctic coastal town of Dikson is fastest-warming place in Russia, The Independent Barents Observer
Sweden: Glacier in central Sweden “collapsing” as climate warms, Radio Sweden
United States: ‘The permafrost is dying’: Alaska city sees increased shifting of roads and buildings, Alaska Dispatch News