Metro Vancouver officials bracing for local impacts of Chilcotin River landslide

Hundreds of kilometres downstream from where water started flowing over of a landslide blocking the Chilcotin River Monday morning, officials in Metro Vancouver are bracing for impacts in the region.

The regional district's emergency services branch posted to social media Monday afternoon, saying further updates will be provided as they become available.

"Water and debris from the Chilcotin River landslide is rushing downstream, and expected to cause intense, high flows and hazards in the lower Fraser River. A high streamflow advisory is in effect and regional park visitors should stay off away from the river," the post said.

"Metro Vancouver emergency management continues to monitor this emergency event closely and collaborate with partner emergency management agencies involved in the response."

The advisory is in effect for the Fraser River downstream from Hope. The distance between Hope and where the river starts to flow through the regional district is more than 100 kilometres.

River levels are expected to rise rapidly but no major flooding is expected. But flooding is only one of the risks signalled by a high streamflow advisory.

"Fast-flowing bodies of water increase risk to life safety," the province's River Forecast Centre says.

The risk of flooding is far higher further upstream, closer to where a massive landslide created a dam in the Chilcotin River that is estimated at 30 metres deep, 1,000 metres long and 600 metres wide.

Between Boston Bar and Hope, a flood watch is in effect meaning that flooding may occur, according to the province.

A flood warning is in effect for the Fraser River between the confluence with the Chilcotin River and Big Bar, which the River Forecast Centre explains means that flooding is all-but certain in areas "adjacent" to the river.

As water continues to spill over the dam, it is expected that "significant quantities of debris and sediment will also be mobilized," the river forecast centre's warning says.

While a worst-case scenario wherein water suddenly surged through the dam instead of gradually flowing over top of it has so far been avoided, Emergency Management Minister Bowinn Ma has repeatedly urged vigilance and warned of the extreme danger associated with being on or near the rivers.