North

Whitehorse sees 4th landslide in a month, 3rd since the weekend

A fourth landslide took place in Whitehorse Tuesday, the second one along Robert Service Way. The city said it had been monitoring the site for weeks and expected it, but it doesn't affect plans to reopen Robert Service Way once the sheet pile wall is built.

Slide was 'fully expected,' says city, adding no other sites along escarpment show similar signs

A top view of the landslide along Robert Service Way that happened on Tuesday. (Submitted by Jeff Bond)

There's been another landslide in Whitehorse, according to an employee of the Yukon Geological Survey (YGS), but it's one that the City of Whitehorse said it "fully expected." 

The YGS's Jeff Bond said he saw the landslide happen Tuesday morning, about 300 metres from the site of the April 30 landslide that saw debris cross Robert Service Way, leading to its closure.

Bond and a crew from YGS were installing a camera near a tension crack, when they saw the ground at the site had let go. 

"You could still see trees settling and ground settling, and you could smell the churned up vegetation in the air," Bond said. 

A spokesperson for the city said it had been watching the area where the landslide took place for weeks.

"The tension crack in this area had reached four metres. Its release was just a matter of time," he wrote in an email to CBC News, adding it happened next to the area where a landslide happened last year.

He wrote there was no other site along the escarpment, which borders the west of downtown, that show similar signs.

City crews are building a 100-metre sheet pile wall at the bottom of where the April 30 landslide happened to mitigate the damage from any future landslide. Once completed, which the city estimates will be in about a week, it plans to reopen Robert Service Way, one of two main thoroughfares into downtown.

The spokesperson said the landslide on Tuesday did not affect the timing or the city's plans to reopen Robert Service Way.

Debris from the April 30 landslide being removed from Robert Service Way. The city cleaned it up last week and started building a 100-metre sheet pile wall Friday. City staff were diverted from it on the weekend to help with the landslides that took place. Construction of the wall was set to resume Tuesday and last another seven to eight days. The city said Tuesday's slide will not affect construction of the wall or the planned reopening of Robert Service Way. (Submitted by City of Whitehorse)

The landslide is the fourth along Whitehorse's escarpment in a month and the third since the weekend.

The city closed off areas along Sixth Avenue from Jeckell Street to Drury Street, and the dog park at the end of Main Street following the two weekend landslides

'We're kind of scratching our heads'

The land that let go in Tuesday's slide was a bit different than in other areas, Bond said. 

Surveyors on the previous slides noticed an over saturation of water in the soil from the melting snow, whereas this most recent spot was dry and full of trees. 

"We're kind of scratching our heads about that," Bond said. "I think it definitely … makes you look at drier areas … and make sure you're looking for tension cracks outside of these highly moist areas." 

The city's spokesperson said the city will continue to monitor the entire escarpment on a daily basis as it has since the April 30 landslide.

Unlike the first landslide, Bond said there was no spillage of sediment or trees onto the highway. 

Bond said he expects more landslides to happen as there are cracks "along a lot of different places on the escarpment."

The city has been saying more landslides will happen as the soil continues to dry and has been asking residents to stay out of the areas it has fenced.

The best advice that Bond has for the public is to stay off the escarpment for the next six weeks. 

"Just wait for things to dry out," he said. "It's going to take some time, even with this warm weather."

ABOUT THE AUTHOR

Anna Desmarais is a videojournalist for CBC North based in Whitehorse. Before that, she spent two years as the South Slave correspondent based in Hay River, N.W.T. She's also reported from Yellowknife, Ottawa, Edmonton, Toronto and Kathmandu. Reach her at anna.desmarais@cbc.ca or @anna_desmarais.