Water has begun moving through the dam formed on the Chilcotin River by a giant landslide, but the warning from officials is a stern one.
“I cannot stress enough how extremely unsafe and unstable the valley is right now,” B.C.’s Minister of Emergency Management, Bowinn Ma, said at a press conference on Monday.
“There is a risk of further landslides both upstream and further downstream of the dam.”
The massive landslide last week at Farwell Canyon located about 22 kilometres south of Williams Lake dammed the Chilcotin River and created a lake about 11 kilometres long behind the slide.
Ma said there have now been five emergency alerts broadcast to people in the area since Wednesday and more will be issued as needed.
She added that people along the Chilcotin River and the Fraser River should stay in contact with their local governments and First Nations.
“We need people to stay off of the Chilcotin and Fraser Rivers and away from the riverbanks,” Ma said.
“It is dangerous to be by those rivers right now.”
Videos taken on Monday morning at the site of the dam show water flowing over the top of the site.
Emergency alerts have been issued to cellphones, radio and television to advise people in the area on or along the riverbanks of the Chilcotin River from Hanceville to the Fraser River, and the Fraser River from the Chilcotin River to the Gang Ranch Road bridge, to evacuate immediately due to flooding and debris flow.
B.C. officials had issued an evacuation order Sunday night for an area just north of where the Chilcotin River meets the Fraser River because of the danger of flooding caused by the landslide.
In a news release late Sunday, officials with the Cariboo Regional District told residents to leave “immediately” and said people who chose to stay did so at their own risk. The evacuation order covered 3.5 square kilometres.
Connie Chapman, executive director of water management with the B.C. government, said at the update that the water started to flow through at about 8:50 a.m. on Monday.
Officials then started to see debris and trees enter the channel and they are expecting more erosion downstream.
Chapman said the breach is developing at a “readily moderate pace” but it could still speed up as conditions change.
The water was flowing at about 750 cubic metres per second as of 1:30 p.m., Chapman added.
The next gage on the system is at Big Bar and it will take a few hours for the water to reach that point, according to the government.
The Tsilhqot’in First Nation said that as of Sunday morning, the slide was holding back 61 million cubic meters of water, equalling “24,400 Olympic swimming pools.”
-with files from The Canadian Press