VANCOUVER:  Torrential rains that pushed southern British Columbia waterways to flood stage have eased, but officials warn the new threat of unseasonable heat could rapidly melt snowpacks, adding to already swollen rivers.

The Regional District of Kootenay Boundary in southeast B.C. says flooding that hit Thursday following two days of heavy rain pushed the Kettle, West Kettle and Granby rivers to levels higher than those recorded during devastating floods 70 years ago.

The district says nearly 1,400 properties were ordered evacuated, but waters rose so quickly that many people were trapped in their homes in Grand Forks on Thursday.

The district says in a news release that all the rivers peaked overnight and work will now focus on reaching trapped residents, determining property and infrastructure damage, and creating a re-entry plan for residents.

Environment Canada forecasts are raising concerns because temperatures across the region are expected reach the high 20s this weekend, nearly 10 degrees above normal.

The hot weather could cover much of the southern and central part B.C. into next week, meaning heavy upper-level snowpacks would melt rapidly and cause further flooding.

The River Forecast Centre says flood warnings are in effect on waterways throughout the Okanagan and Boundary regions while flood watches are posted for many other rivers and streams, including the Similkameen and Tulameen rivers west of Grand Forks.

Parts of the town of Osoyoos were ordered evacuated Thursday and flooding is also reported in Keremeos, Cawston and Okanagan Falls.

Osoyoos, which is along the Canada-U.S. border, has declared a state of local emergency and ordered homeowners with flooded basements to stop pumping the water back into the town’s sewer system.

“The act of causing this water to enter the sewer system in current conditions is causing pump infrastructure to function beyond capacity, which may result in a breakdown of the town sewer management system,” says a news release issued by the town.

An update on flooding around the province is expected Friday from officials with Emergency Management BC and the River Forecast Centre, which monitors river and snowpack levels across B.C.

The Canadian Press