The rising Fraser River has those living near its banks preparing to flee should existing evacuation alerts turn to orders.
Alerts are in place for parts of Barnston Island, Langley, Abbotsford and Chilliwack, and residents have been told to be ready to leave at a moment's notice.
The river is high and flowing fast due to sudden warm weather and a fast-melting snowpack.
In Fort Langley, a team was setting up a new Tiger Dam – a reusable flood barrier filled with water that can be twisted in any shape and can be used to replace as many as 500 sandbags, according to the U.S.-based manufacturer.
"We're fighting water with water," Metro Vancouver Regional Parks supervisor Doug Petersen said.
Some of the dams were anchored down and used to protect a heritage home. The dams just arrived three weeks ago, and Thursday's set-up was the first test.
Sandbags were sent over to those living in the Fraser's midst on Barnston Island. Residents were told to consider leaving early and getting livestock off the island immediately, as both large animals and vehicles will be barred from the ferry that services the community of 155 should an evacuation order be issued.
"I'd say this year is potentially the worst freshet I've personally experienced," said Rod Tulett, Barnston Island incident commander.
"We are about three weeks ahead of normal, and the water has been rising as fast as we've ever seen it in the past."
Alerts were issued to those on the island between Surrey and Pitt Meadows Wednesday. Residents including members of the Katzie First Nation acted quickly, sandbagging their homes and transporting horses, cows and goats off the island.
The Barnston alert came a day after a similar warning was issued in the Township of Langley. On Tuesday, officials warned the areas of Northwest Langley, Glen Valley, Brae Island and McMillan Island were at risk of flooding.
More than 100 concerned residents of Surrey's Bridgeview neighbourhood attended a meeting Wednesday night to hear how the city is preparing, actions which include fortifying the dike.
"We're preparing for the worst but we expect much, much better than that," the city's utilities manager Jeff Arason said.
Tom Jones, co-owner of a sawmill in Port Kells, was less optimistic.
"It will be a hell of a mess for a lot of people," he told CTV News Thursday morning. "Nature's going to do what it wants."
Jones said he thinks the Fraser should be dredged to remove decades worth of sand and silt.
"It'll make the river deeper. It'll take it back to what it was 50, 100 years ago."
For now, all eyes are on the river, which is expected to keep rising through the week. The Mission gauge is currently sitting at 5.8 metres, but is predicted to peak at 6.6 during the weekend or early next week.
But the estimates could change depending on weather. Rain could make the situation a lot worse, but high temperatures are also adding to the surge.
Premier John Horgan, Liberal leader Andrew Wilkinson and several MLAs toured the Fraser by air Wednesday, and told reporters they're keeping a close eye on flooding across the province.
Further inland, the entire southeastern corner of B.C. is under a special weather statement, where rain and thunderstorms could increase the flood risk in areas still reeling from last week's flooding.
The federal government has promised to send help to the region, including support from the Canadian Armed Forces.
With a report from CTV Vancouver's Nafeesa Karim and Allison Hurst
