Officials say the slide on Baker Creek, about three kilometres upstream from the Fraser River near Pinnacles Provincial Park, may have occurred late last month, creating a blockage and backing up water to a depth of three to 3.6 metres.
If the blockage is breached, homes would be made vulnerable to flooding quite quickly, said Quesnel fire chief Sylvain Gauthier.
"If the slide fails and all this water is just going right through it in one shot, it would take approximately 30 to 35 minutes to make its way to the city limits, where some of the housing are located right beside the creek," Gauthier told CBC News. "It could jeopardize some of the housing through a major flash flood."
Specialists with Emergency Management BC have already visited the site on Baker Creek in Quesnel, 114 kilometres south of Prince George.
Officials are urging residents to evacuate the area around the creek until further notice.
The state of emergency is not expected to be lifted until at least Monday.
Falling tree kills 11-year-old boy
Meanwhile, residents of Grand Forks — about 500 kilometres south of Quesnel — are still recovering from a deadly storm that hit Friday afternoon.
An 11-year-old boy was killed when trees fell on the hut where he was sleeping at the Pines Bible Camp. His name has not been released, but officials say he was from Christina Lake, where the community is now pulling together.
"We were all gathered at the community hall when we heard about this and so we did ... take a moment and send our sympathies to the family, everybody being very, very affected by it," said Grace McGregor with the Kootenay Boundary Regional District.
Officials say there will be a memorial for the boy but the details haven't been worked out.
No one else at the camp was injured, though there were about 100 other kids and staff members on site. The camp was left in bad shape.
"I could see the wind picking up and the storm picking up, and I just came around one of the corners and there was a big tree across the road I was able to get past, and then another and another, and power lines down," said Jonathan Christian, who was a guest speaker at the camp for the week.
Extent of damage unclear
Christian, who is also a board member for the camp's ministry, photographed the storm and the damage.
"Seventy per cent of the trees around the camp are down, probably half of the sleeping cabins are badly damaged, the big gymnasium is a steel structure, that's been compromised," he said. "And we don't know what the damage is to a lot of the buildings because we can't get in them."
It's not clear how much it will cost to repair the damage. The camp is in a remote location, so getting labour and supplies to the site will be expensive.
But offers of help are already pouring in.
"We're relying on the community to really rally around us and help us, both with volunteer time and resources and donations as well, so we can get the camp ready before the winter, so we can be tight and reopen again next summer," Christian said.
A fundraiser for the camp is planned for Tuesday in Abbotsford.
The storm also brought down power lines across the Okanagan and the Kootenays. At one point, about 20,000 customers were left without power.
The weather has wreaked havoc in B.C. in recent months. A landslide in Johnsons Landing killed four people, a mudslide left hundreds of people stranded in Fairmont Hot Springs and widespread flooding closed highways and drove residents from their homes.
Also on HuffPost