The province of British Columbia issued an emergency alert Monday morning after water began spilling over the landslide blocking the Chilcotin River.
Gerald Pinchbeck with the Cariboo Regional District Emergency Operations Centre told CBC News that water began moving over the dam around 9 a.m. PT.
The province’s emergency alert, sent at at 10:35 a.m. PT, urged residents anywhere along the banks of the Chilcotin River from Hanceville to the Fraser River, and anywhere along the banks of the Fraser River from the Chilcotin River to the Gang Ranch bridge around 25 kilometres downstream, to evacuate immediately.
“The going concern are debris flows, which aren’t included in the [river flow] modelling,” Pinchbeck said. “We don’t know what those impacts will be, but our concern is for the safety of people and infrastructure in the area.”
In an update posted on Monday, the province said “woody debris” is already being carried down the Chilcotin and Fraser rivers.
As more water moves over the slide, officials are expecting it to carry more debris, including fallen trees. Water levels along the Chilcotin River are expected to rise far above normal spring melt levels, while water levels along the Fraser River are expected to be below spring levels.
In a news release, the province asked people to stay away from the rivers due to the risk of fast-moving water and debris.
“Even if the water elevation in an area may be similar to freshet (spring flooding) levels, the water will react differently, with greater momentum and force, than a gradual increase in water levels,” it said.
Bowinn Ma, B.C.’s Emergency Preparedness and Climate Change Minister, is scheduled to provide an update at 2 p.m. PT. CBC will carry the livestream here.
Evacuation orders are in place along parts of the Chilcotin and Fraser rivers and people are being urged to stay away from the banks of both waterways.
On Sunday night, the Cariboo Regional District issued three new evacuation orders along the Fraser River. One covers about 9.6 square kilometres along the Fraser River, just south of where it meets the Chilcotin River. A second order covers 3.5 square kilomtres along the Fraser River just north of that confluence, upstream.
“Once the water hits the Fraser River from the Chilcotin River, it’ll go where it can,” Pinchbeck said. “If there’s enough water coming down, it will go upstream and also it will eventually flow downstream.”
A third evacuation order covers 1.5 square kilometres along the Fraser River, about 25 kilometres south of where the two rivers meet. It includes the Gang Ranch Suspension Bridge.
Evacuation orders also remain in place for about 100 square kilometres of land along the Chilcotin River, both upstream and downstream from where the landslide happened near Farwell Canyon.
In total, evacuation orders stretch from near Hanceville, B.C., to where the Chilcotin and Fraser rivers meet.
Several jurisdictions also issued evacuation alerts, which ask residents to prepare for an evacuation at short notice.
Just after noon on Monday, the Thompson-Nicola Regional District issued an evacuation alert for all private properties within 300 metres of either side of the Fraser River, including four properties it listed in the Big Bar area.
The regional district posted a map of the evacuation alert area online.
The Cariboo Regional District has an online interactive map showing an evacuation alert along either side of the Fraser River within its jurisdiction.
B.C.’s Ministry of Water, Land and Resource Stewardship could not be immediately reached for comment.
In a news release Sunday, the ministry said peak flows along the Chilcotin River could be more than 10 times greater than typical levels after the spring melt.
It estimates the river could rise by 21 metres at the Farwell Canyon bridge, close to the site of the landslide, about 285 kilometres north of Vancouver. Peak flow could take up to 13 hours to reach Lillooet.
In a post to social media, Minister of Water, Land and Resource Stewardship Nathan Cullen confirmed water has moved past the landslide.
Some important developments on the Chilcotin slide. <br><br>We’re seeing the first images from moments ago of water getting through the slide.<br><br>We’ll be getting more detailed information in the coming hours. <a href=”https://twitter.com/hashtag/bcpoli?src=hash&ref_src=twsrc%5Etfw”>#bcpoli</a> <a href=”https://twitter.com/BowinnMa?ref_src=twsrc%5Etfw”>@BowinnMa</a> <a href=”https://t.co/m5k8WTYmEz”>pic.twitter.com/m5k8WTYmEz</a>
—@nathancullen
The landslide was first reported by residents near Farwell Canyon last Wednesday morning. The slide created a dam about 30 metres high, 600 metres wide and a kilometre long.
Since then, officials have warned that water would eventually spill over the dam.
The Ministry of Water, Land and Resource Stewardship told reporters on Sunday that risks to public safety include the potential for further landslides upstream of the natural dam and downstream of the dam once water begins to flow past it.
On Sunday the province launched a new Chilcotin River landslide information portal to share the latest information about the slide with the public.
According to the province’s latest update, staff that were previously studying the landslide have been moved a safe distance away, where they continue to assess the area.
They expect an increased risk of landslides about 16 kilometres upstream of the landslide, and have already seen some smaller ones.