Updated modelling of the landslide across the Chilcotin River provides an improved assessment of worst-case scenario risks to people and communities from a sudden failure of the landslide structure and associated flooding.
Expert modelling indicates that even in the worst-case scenario (a sudden failure of the natural dam), water levels in the Fraser River are anticipated to be below freshet (spring snowmelt) season levels. However, flows in the Chilcotin River are expected to be far above normal freshet flows, with potentially significant impacts on the local ecosystem and risks to public safety.
The latest data also suggest that the worst-case scenario of a sudden breach is less likely than a slower release, which would result in lower increases in water levels in both the Chilcotin and Fraser rivers.
There remain risks to public safety, including the potential of further landslides upstream of the natural dam and downstream once the water begins to flow through.
People are urged to keep out of the Chilcotin River valley between Hanceville and the confluence of Fraser River. An evacuation order by the Cariboo Regional District remains in place. People are also advised to stay away from the banks of the Fraser River.
The landslide incident poses potential impacts to spawning salmon and other fish species. The Province is working with First Nations and Fisheries and Oceans Canada to establish an incident command structure, mobilize resources and plan mitigation efforts.
The Province is preparing for all possible outcomes. While the latest models are encouraging, they do not provide guarantees. Provincial personnel and partnering agencies continue to work day and night to provide real-time information from the site, to prepare for any mitigation that may be necessary, and to keep people in British Columbia informed and safe.
It is still uncertain when and how the water pooling behind the dam will re-enter the Chilcotin River, but it could occur at any time. The Province is actively monitoring the situation 24/7 and will continue to share the latest information with the public as it becomes available.