05 Aug 2024 | 06:08 AM UTC
Canada: Evacuation orders in place following landslide and possible flooding on Chilcotin River, British Columbia, as of late Aug. 4 /update 1
Evacuation orders remain in place following landslide and possible flooding on Chilcotin River, British Columbia, Canada, as of late Aug. 4
Evacuation orders remain in place following a landslide and possible flooding on the Chilcotin River in southern British Columbia as of late Aug. 4. A landslide in the Farewell Canyon area early July 31 blocked parts of the Chilcotin River. The landslide injured one person. Authorities have warned that the water level behind the natural dam created by the landslide has continued to increase steadily in recent days; the trapped water is likely to move through and past the blockage over the coming hours. River levels are likely to rise rapidly; flooding is likely.
Authorities are maintaining evacuation orders for the area immediately south of the Chilcotin River's confluence with the Fraser River, the Churn Creek Bridge area, and the Chilcotin River Landslide area. Evacuation alerts are in place for the area along the Fraser River downstream from the confluence with the Chilcotin River and south to the Cariboo Regional District's boundary. The Thompson Nicola Regional District issued precautionary closures of the Big Bar and Lytton ferry services on the Fraser River.
A flood warning is in place for the Chilcotin River upstream and downstream of the landslide around Farwell Canyon, while a flood watch is in effect for the Fraser River from the Chilcotin River confluence downstream to Hope. A high streamflow advisory has been issued for the Fraser River downstream of Hope.
Sustained heavy rainfall could trigger further landslides in hilly or mountainous areas, especially where the soil is already saturated from previous downpours. Heavy showers could also trigger flooding in low-lying communities near rivers, streams, and creeks. Urban flooding is also possible in developed areas with easily overwhelmed stormwater drainage systems. Sites located downstream from large reservoirs or rivers may be subject to flash flooding after relatively short periods of intense rainfall.
Authorities could issue further mandatory evacuation orders for landslide-prone communities over the coming days. Where significant flooding or landslides impact utility networks, disruptions to electricity and telecommunications services are possible.
Road closures are likely within and around areas where mandatory evacuation orders have been issued. Further landslides could block sections of roads and railways in the affected region. Residents' return could disrupt traffic flows after authorities lift evacuation orders.
Flooding triggered by heavy rainfall could also render some bridges, rail networks, or roadways impassable, impacting overland travel in and around affected areas. Ponding on road surfaces could cause hazardous driving conditions on regional highways. Authorities could temporarily close some low-lying routes that become inundated by floodwaters.
Heed any evacuation orders issued by authorities. Seek updated information on road conditions if driving in the affected area; road closures and detours will cause increased congestion and delays. Do not drive on flooded roads. Charge battery-powered devices in the case of prolonged electricity outages.