The province is warning that the hot weather, along with continued rainfall, could continue to push water levels up across much of B.C.
“The prolonged nature and severity of the temperatures we’ve seen are unprecedented,” said River Forecast Centre head David Campbell in a Thursday update.
The rain over the next 24-36 hours will be the most important factor to determine how much flooding there would be, he said, urging people to be careful near any riverbanks or lakeshore areas.
About 3,600 people are currently under evacuation order and 7,100 are under alert, with 36 local states of emergency in effect.
Emergency Management BC has activated all its regional emergency operation centres. Executive director Chris Duffy said the government has reached out the other provinces and Ottawa for assistance.
The Trudeau government said it is sending about 150 members of the Canadian Armed Forces to B.C., although they are being deployed in the interior to help with the floods ravaging the Grand Forks area.
Grand Forks, which has around 2,500 people under evacuation order, could see more flooding in the coming week if rain continues to pour.
“This will push the risks of extreme flooding through… Boundary and the Kootenays,” said Campbell.
In the Okanagan, Shaun Reimer, who is the section head for public safety and protection at the Okanagan for the forests ministry, said Okanagan Lake is rising by five to six centimetres a day and is expected to peak at 343 metres above sea level in early to mid-June.
Reimer cautioned the area’s residents not to panic, noting this was the level that flood protection works should be built up to and not a guarantee that the lake would rise that high.
However, he said water was coming into Okanagan Lake even faster than it did in 2017 because of the “historic” heatwave. Temperatures have touched the 30s in recent days.
In the Lower Mainland, Campbell warned those living near the Fraser River but not protected by a dike to watch for rising flood waters.
“That’s similar to flows we saw in 2012,” said Campbell, adding those levels could rise even higher over the next couple weeks.
“We’re expecting flows on the lower Fraser that we really haven’t experienced in many decades.”
The diking network along the Fraser, in Surrey, Langley and into the Fraser Valley, are designed to withstand the 1894 “flood of record” in the region.
“That’s 8.9 metres [high] at Mission, plus half a metre of freeboard above that,” said Campbell. “We’re not expecting anything near to that level.”
Currently, parts of rural Langley, Abbotsford and Barnston Island are under evacuation alert. No one is under any evacuation order.