Water breaches landslide damming Chilcotin River

UPDATE, Aug. 6, 2024:Surge of water from Chilcotin landslide dam breach fills Fraser River

People are being urged to stay away from the banks of the Chilcotin and Fraser rivers after waterfinally breached the dam created by last week's huge landslide.

The province of British Columbia issued an emergency alert Monday morning after water beganspilling over the slide blocking the Chilcotin River.

The 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.

At a news conference Monday afternoon, Connie Chapmanwith B.C.'s Ministry of Water, Land and Resource Stewardship said the water had since created a 15-metre-wide channel in the dam and was breaching it at a "moderate pace." She added the dam is carrying wooddebris downstream.

WATCH | Water spills over Chilcotin River landslide:

Chilcotin River breaches landslide

29 days ago

Duration 0:19

Water from the Chilcotin River has begun to spill over a landslide that has blocked the river since the July 30.

Gerald Pinchbeck with the Cariboo Regional District Emergency Operations Centretold CBC News earlier that it's the debris he's worried about.

"The going concern are debris flows, which aren't included in the [river flow] modelling.We don't know what those impacts will be, but our concern is for the safety of people and infrastructure in the area," said Pinchbeck, who added that water had begun moving over the dam around 9 a.m. PT.

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.

"I cannot underline enough how extremely dangerous the valley is right now," Emergency Preparedness and Climate Change Minister Bowinn Matold reporters at the 2 p.m. briefing.

"We need people to stay off the Chilcotin and Fraser rivers and stay away from the river banks."

She said it's not clear when the rivers and their banks will be safe again.

WATCH | Aerial footage shows debris flowing through Chilcotin River:

Debris flows in B.C. river after water buildup bursts through landslide

29 days ago

Duration 1:06

Footage shot by Trevor Chelsea from a helicopter shows the Chilcotin River flowing with significant force on Monday, nearly five days after a landslide dammed the river and caused a significant buildup. CORRECTION (Aug. 6, 2024): A previous description said the footage was shot Tuesday; in fact, it was Monday.

Evacuation orders, alerts

Evacuation orders are in place along parts of the Chilcotin and Fraser rivers, affecting about 11 properties and about 10 peoplein the Cariboo Regional District.

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 kilometres along the Fraser River just north of that confluence, upstream.

"Once the water hits the Fraser River from the ChilcotinRiver, 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 alsoremain 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.

On Monday afternoon the B.C. River Forecast Centre also issueda flood warning fortheFraser River from theChilcotinRiver confluence to Big Bar.

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 onlineinteractive map showingan evacuation alert along either side of the Fraser River within its jurisdiction.

Peak flows

In a news release Sunday, officials 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.

Minister of Water, Land and Resource Stewardship Nathan Cullenposted video to social media of water moving past the landslide.

Cullen told CBC's On The Coast onMonday that the breach is expected to move up to threemillion dump trucks worth of soil in the coming days.

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.

Chapman told reportersMonday 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.

WATCH | 100 kilometres of riverbank has been evacuated:

Water breaches dam on Chilcotin River

29 days ago

Duration 2:01

People have been warned to stay away from the Chilcotin and Fraser rivers after water that pooled behind a natural dam, formed by a landslide last week, surged through and headed downstream.

On Sunday the province launched a new Chilcotin River landslide information portal to share the latest information about the slide with the public.

Chapman said 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.

According to Chapman, from the time water breached the dam until noon on Monday, the lake that had builtup behind the slide was dropping at a rate of 20 centimetres per hour. Since then, the flow of the breach has increased and thelake is dropping about 1.3 metres per hour.