Cooler temperatures hold off NWT spring breakup
Spring breakup in the Northwest Territories has been delayed slightly by cooler temperatures, the territorial government said this week.
Even so, a water monitoring bulletin published by the Department of Environment and Natural Resources on Monday stated snowmelt was ongoing and breakup had begun in upstream areas of the Hay River.
Warmer weather in the coming days is expected to melt residual snowpack and hasten the melt of river ice across the southern NWT.
ENR has already warned of the potential for more flooding this season on the Hay, Liard and Mackenzie rivers, as well as in Aklavik. Temperature will be critical for those monitoring flood risk, as will the rate of snowmelt and how the ice breaks up.
Slow and steady increases in temperature allow for a progressive snowmelt and ice melt, making ice jams and rapid water level spikes less likely.
Record highs in Hay River
On the Hay River, warm temperatures in northern Alberta have contributed to a sharp rise in water levels at monitoring stations along the river system leading from Alberta to the NWT.
On Tuesday, the town said levels on the Hay River between the NWT-Alberta border and the town had risen three to five feet in the past day. Surface water had increased at Alexandra Falls, Paradise Valley, Pine Point Bridge, and the West Channel bridge, though the river had yet to break up near the upstream community of Meander River. (By Wednesday morning, after this article was first published, the town said the river had since broken at Meander River.)
ENR has said water levels are at or near their highest on record in Hay River for this time of year. The ground is heavily saturated, meaning almost all rain and melting snow will flow directly into the river, increasing already-high levels.
Vale Island and West Channel residents are being encouraged to follow flood preparedness recommendations distributed by the town. The town will be running an RV park at the Hay River Community Centre from Wednesday – call reception to arrange set-up in advance.
Public updates will continue daily online at 10am and 5pm.
Above-average Liard River snowpack
Snowpack is continuing to melt across the Liard River basin and water levels are slowly beginning to rise underneath the ice at Fort Liard. Breakup has reportedly begun in the Upper Liard in the Yukon but has not reached the NWT section of the river.
With warm temperatures and possible rain in the forecast, breakup further along the Liard is expected soon.
ENR has said snowpack in the upper basin is almost twice its average size and, at some locations, the highest on record. Snowpack is also higher, but not quite to the same extent, in the lower basin.
More information about Fort Liard’s emergency response plan can be found on the hamlet’s website. Downstream, residents of Nahanni Butte are asked to fill out evacuation registration forms, available at the recreation centre, and submit them to the band office as soon as possible.
Mackenzie River: watch and wait
While breakup is well under way in the Peace River and Athabasca basins, which drain into the Slave river, breakup has not yet commenced on the Mackenzie River.
GNWT snow surveys show sections of Dehcho snowpack are 68 percent higher than normal and 23 percent higher in the Sahtu. Water levels on the Mackenzie River and in the Mackenzie Delta are lower than 2021’s record highs but still higher than average, and ice jam-related flooding is a possibility.
Residents of Fort Simpson can find more information about flood preparedness on the village’s website. Fort Providence and Jean Marie River haven’t published community-specific flood preparedness guides online, but residents can follow Maca’s online guide to flood safety.