Water is now flowing over the site of an enormous landslide blocking the Chilcotin River, south of Williams Lake in B.C.’s Central Interior.
Videos taken on Monday morning show the water starting to move across the top of the site.
A BC Emergency alert has 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.
Additional BC Emergency alerts will be issued to people downstream on and along the Fraser River as peak flows progress, according to the provincial government.
The lake behind the slide has been building up, growing steadily at a pace of 18 centimetres an hour in recent days.
There is still the risk of the dam coming apart, sending the water quickly down the dry riverbed.
In the worst-case scenario, officials said the dam rapidly drains within an hour and would likely result in below-peak flows for the Fraser River.
The water in the Chilcotin River could potentially rise to 21 metres at the Farwell Canyon bridge and 12 metres where the Chilcotin River meets the Fraser River.
Located around 100 km southwest of Williams Lake, the landslide came down Wednesday morning, damming the river and creating a temporary lake.
Real-time water-level monitoring information is publicly available through the Water Survey of Canada.
The provincial government has also launched a new web portal to provide the latest information on the Chilcotin River landslide.