Water expected to flow over Chilcotin landslide

UPDATE Aug. 5, 2024:Water begins spilling over landslide damming Chilcotin River

British Columbia's emergency management ministry said Sunday that water is expected to start moving over the top of the massive landslide blocking the Chilcotin River within hours.

LastWednesday, an overnight landslidecreated a dam across the river roughly600 metres wide and 30 metres tall.Debris, like fallen trees, and water have been building up behind the landslide for days.

Since then, officials have warned thatdam will fail.

Evacuation orders remain in place for about 100 square kilometres of land along the Chilcotin River, stretching from near Hanceville, B.C., to where the Chilcotin and Fraser rivers meet. The orders affect 13 residents, according to officials, and about 2,500 cattle.

On Sunday night, the Cariboo Regional District Emergency Operations Centre (EOC) issued an evacuation order for eight parcels south of the confluence of Chilcotin and Fraser rivers, covering about 9.62 square kilometres.Two parcels about 1.57 square kilometresin the Churn Creek Bridge Area arealso under evacuation order.

Stay away from the riverbanks, warns official

Gerald Pinchbeck, information officer for the regional district's EOC, says flooding and debris are expected from the landslide. He'surging locals to stay away from the Fraser River and adjacent riverbanks.

"These debris will include dislodged trees, logs and other wooden material that will create hazard for people and infrastructure in the river," he told CBC News.

"The most critical thing right now is people stay off the river and river banks. This is a historic slide, a historical release of water, and it comes with historic consequences."

Pinchbeck says evacuees can access emergency services at Williams Lake, north of the Churn Creek area.

In a statement Sunday, the ministry saidit's continuouslymonitoring the area, conducting aerial survey flights and gathering additional technical data.

"We are not letting our guard down even for a second," saidNathan Cullen, B.C.'s minister of water, land and resource stewardship.

Water will take up to14 hours to pass through blockage

The ministry anticipates thewater will start to move overthe blockage late on Sunday or early on Monday,and enter the riverbed below the slide site.

The water level behind the natural dam has been rising steadily since the landslide at a rate of about 18 centimetresper hour.

According to current estimates, it will take 12 to 24 hours for the water to pass through the blockage. This will cause water flow to be about 10 timeshigher than usual in the Chilcotin River but lower than typical spring runoff Fraser River.

WATCH |B.C. Interior prepares for flooding after landslide:

B.C. Interior braces for possible flooding after massive landslide

1 month ago

Duration 2:31

B.C. residents, the provincial government and First Nations are bracing for a possible deluge of water after a massive landslide dammed the Chilcotin River in B.C.s Cariboo region. Officials warn impacts could be significant if the slide gives way.

The ministry says a worst-case scenario could involve a rapid draining of the slide site, which could result in a 21-metre rise of the Chilcotin River near the Farwell Canyon Bridge.

On Sunday evening, B.C.'s River Forecast Centreissued an upgradedflood warning, signalling waterlevels are expected to rise past river banks imminentlyfor the Chilcotin River downstream of the landslide near Farwell Canyon.

"This situation is very dynamic,andI want to be clear that the valley couldbe extremely unstable and dangerous," B.C. Emergency Preparedness and Climate Change Minister Bowinn Ma said during a press conferenceon Saturday.

Health-care patients relocated

The province launched a new ChilcotinRiver landslide information portal on Sunday afternoonto share the latest information about the slide with the public.

The ministry says 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.

The peak flow could take up to 13 hours to reach Lillooet, B.C., according to the province. Ma said several patients have been relocated away from health-care centres in Lillooet,in case floods lead to an emergency situation there.

The minister addedseveral residents have been seen returning to the evacuated zoneto look at the landslide and fly drones in the area.

"Operation of any aircraft that is not part of the landslide response is illegal in this area," Ma said. "This is extremely dangerous, and poses a threat to both the people that re-enter thearea and the experts assessing the situation on the ground."

The minister urges people toheed evacuation orders and alerts and stay away from the river areas.

Missing dog found

One camper was caught in the landslide, according to paramedics. On Wednesday morning,he was rescued and airlifted him to Williams Lake, B.C., where he was taken to hospital.

The man was separated from his dog, Seiko, in the landslide.

Gerald Pinchbeck, with the Cariboo Regional District's emergency operations centre, told CBC News on Friday that Seiko had been spotted along Highway 20 and has since been reunited with his owner in Williams Lake.

"We had our hearts out and thoughts out hoping that this dog would make it through," Pinchbeck said. "We're very relieved that he did."