Communities watching high snowpack
Flooding possible if heavy rain or hot weather kick-starts a slow spring melt
A cooler-than-normal spring has put off immediate flood threats in B.C. from the melt of mountain snowpacks, known as the spring freshet.
But there are higher-than-normal mountain snow levels in some Interior regions. The possibility of a hot spell or heavy rain causing quick melt has provincial and community officials keeping a close eye on the weather and undertaking some preparations such as stockpiling sandbags.
While the province has no flood warnings up, several high stream alerts have been issued, including for the Deadman River, which empties into the Thompson River in the B.C. Interior.
Potentially affected is the Skeetchestn Indian Band, about 60 kilometres by road northwest of Kamloops.
“If we get a huge amount of rain, that's where it can be problematic,” Skeetchestn Chief Darrel Draney said Monday. “The (Deadman) hasn't peaked yet. We still have some wiggle room. I hope we don't have to use it.”
About 400 people could be affected if there is flooding, Draney said.
Steps have been taken with the help of the province and Enbridge, whose pipeline runs through the river valley, he said.
Those include armouring riverbanks with rock to prevent erosion, improving drainage, strengthening bridges, creating an emergency evacuation route and stockpiling more rock and gravel.
In an online video post to community members earlier this spring, Draney noted that wildfires in the watershed could exacerbate any flooding because of increased run-off.
Watersheds that have been burned badly by wildfires can reduce the ground's ability to absorb water and means water will run off the soil rather than soaking in, according to experts.
The Skeetchestn community was evacuated for nearly three weeks last summer due to wildfires, although no homes were burned — and was also evacuated in 2017 due to wildfires.
The Thompson-Nicola Regional District, or TNRD, has a higher-than-normal snowpack but district officials said the short-term weather will be a significant driver of the freshet severity.
“Many areas throughout the TNRD will be vulnerable given the intense and wide-reaching wildfires of last summer, and the atmospheric river flooding last November,” said regional district emergency program coordinator Kevin Skrepnek.
Weather forecasts are being closely monitored, sandbags have been stockpiled for rapid use and more can be brought in short order, Skrepnek said.
The district is also building berms and doing rock work on riverbanks affected by last November's flooding, including in Brookmere southeast of Merritt, to ensure they are reinforced before spring high water, he said.
A two-week cold snap that has kept temperatures in B.C. between five and 10 degrees cooler than normal could lead to minimal early spring flooding in the Fraser Basin, said a Weather Network meteorologist.
However, if things become unusually warm in late May and early June, the record snowpack in the Rockies and near-record in the Cariboo might mean trouble.
Meteorologist Kevin McKay said nicer spring weather that will follow the cold snap could be a concern if it gets too warm because in the Cariboo — that feeds into the Fraser River — the snowpack is on the top end of the range, while the Rockies — that feed into the Fraser and Columbia River basins — have a record snowpack at the moment.
“Right now, it's a perfect situation to avoid the flooding, but it may be a case of postponing the inevitable if we go from a cold trend to every day being 25 degrees in the Interior and 20 in Vancouver,” he said.