A surge of water and debris from the Chilcotin River landslide will hit the Hope area on Tuesday (Aug. 6), says government officials.
According to B.C.'s executive director of water management Connie Chapman, the river at Lytton, Boston Bar, and Hope will be affected by the surge at various points throughout the day. By 7:30 a.m. Lytton will likely be impacted, with water an estimated 3.3 metres above normal; Boston Bar is expected to see river levels rise 2.6 metres by 11 a.m.; and Hope will see water rise about one metre by around 3:30 p.m.
Flooding is not expected for these areas though the province acknowledges that circumstances can change as their data "does not provide guarantees." Residents are also asked to stay away from the banks of the Fraser River due to risks of fast flowing debris and "further landslides upstream of the natural dam and downstream of the dam once water begins to flow past it."
Both the District of Hope and the province also remind locals to keep checking for updates on the emergency situation.
"I cannot underline enough how extremely unstable and dangerous the valley is right now," Minister of Emergency Management and Climate Readiness Bowinn Ma said Monday afternoon (Aug.5). "Now is not the time to go boating. Now is not the time to go take a look at the water."
Government officials said the water began pouring over the blockage southwest of Williams Lake on Monday, around 9 a.m. and has been picking up speed every hour since. The blockage created a lake that extended "several kilometres upstream."
By 1:30 p.m. Chapman said the lake built up behind the landslide was dropping at 1.3 metres per hour and the surge of water coming out of it was travelling at about 750 cubic metres per second. Though this flow is lower than what is seen during a spring snowmelt, it is still significantly faster than the river's normal flow.
The landslide, which took place overnight from July 30 to July 31, dammed the Chilcotin River near Farwell Canyon. It was estimated to be 1,000 metres long, 600 metres wide and 30 metres deep.
Due to the situation, the Hope area continues to be on a flood watch and high streamflow advisory. Residents are asked to sign up for the Alertable app and make sure notifications are turned on for the app.
Residents are also asked to check for updates from the district's social media sites, as well as from EmergencyInfoBC, PreparedBC, and the River Forecast Centre.
The B.C. government also launched a web portal to provide the public with updates on the landslide. The portal can be found at www.gov.bc.ca/landslide .
In addition to the emergency alert covering the Chilcotin and Fraser rivers in general, some properties are also under evacuation alert or order. The province said 11 properties are under order in the Cariboo Regional District. A further one property is under alert there, in addition to four properties under alert in the Thompson-Nicola Regional District.
— with files from Jane Skrypnek and Monica Lamb-Yorski
