B.C. Interior braces for Chilcotin River landslide flooding

As residents, the B.C. government and First Nations prepare for water to surge through a landslide blocking the Chilcotin River, officials are warning of unpredictable water conditions along the Chilcotin and Fraser rivers. 

At a Friday afternoon news conference, Emergency Management Minister Bowinn Ma said current modelling shows water is more likely to go over the top than burst through in a sudden release.

Ma says the impacts downstream could still be significant depending on the distribution of the overtopping flow, and people along the Chilcotin and the connecting Fraser River may need to leave the area.

Ma says it would take 12 to 24 hours for water and debris from the dam to reach Hope, B.C., about 500 kilometres away.

The lake behind the dam has grown to 11 kilometres long. Ma said a new estimate of the length of the blockage is about 1,000 metres along the river. 

She asked B.C. residents to stay away from the Chilcotin and Fraser riverbanks and to refrain from boating on these bodies of water. 

"It's not going to go crashing over and wipe out a town or anything like that. That's only in movies. This is real life," Chief Joe Alphonse, the tribal chair of the Tŝilhqot'in Nation, told CBC News Friday. "But there will be a lot of debris that will flow, and the water is going to be really affected."

The landslide earlier this week blocked the Chilcotin near Farwell Canyon, about 285 kilometres north of Vancouver. Residents of a nearby ranch reported it Wednesday morning. 

That day, the Cariboo Regional District (CRD) ordered evacuations over 107 square kilometres along the Chilcotin River, stretching from where it met the Fraser River to near Hanceville, B.C. 

Since then, officials have been expecting the dam to breach. CRD chair Margot Wagner told reporters Thursday that the dam caused by the landslide was 600 metres wide and 30 metres high, and it was holding back a lake filled with debris, including fallen trees.

She said water is expected to surge past the dam in the coming days. 

B.C. Water and Land Stewardship Minister Nathan Cullen said crews were assessing the situation from above. The B.C. Wildfire Service also sent helicopters to help ministry staff create maps of the slide, so they could assess the damage. 

Gerald Pinchbeck with the Cariboo Regional District's emergency operations centre told CBC New Friday morning he had not received any more information, and officials aren't sure what will happen next.

Alphonse said landslides are common for the area. The Tŝilhqot'in name for the place where the landslide happened is Nagwentled, which he said means landslide area. 

He said when the flood happens, he expects water levels to rise along the river system.

"We hope and we pray that it's going to happen in the current the best way possible," he said. "Use common sense. Stay away from the river banks."

One man was rescued and taken to hospital Wednesday after becoming trapped by the slide. No other injuries related to the landslide have been reported. 

Alphonse said Friday that a landslide that dammed the river two decades ago burst in about four days, but this latest slide is "a lot larger than it was last time."

"This is not really anything new for us," he said. "There's not a lot we can do." 

Alphonse said there's not much use in worrying about what may happen, other than hoping people don't get too close to the water should it rapidly rise after the debris clears.

He said a salmon run expected late next week has already likely been affected, and "that run is now in jeopardy, and that's very concerning for us." 

"We should have a fishery going on right now," he said. "We are dependent on salmon runs for healthy living. That's the main source of food for our people."