Early break-up season signs are positive, NWT experts say

After back-to-back years of significant flooding in the Northwest Territories, officials say 2023 is shaping up to offer a quieter spring break-up season.

Many of the conditions that led to flooding in 2021 and 2022 have improved, territorial representatives said at a briefing for reporters held on Friday afternoon.

There is less moisture saturating the ground due to last year’s warm, dry summer, while water levels and snowpack – the amount of snow accumulating on the ground over the winter – are back to average amounts across much of the NWT. To date, there has been no extreme rainfall this spring.

Yet the territory still cautioned in its spring outlook that how the weather unfolds over the next few weeks could have a large impact on flood risk at break-up.

“What we like to see are warming periods, followed by slightly cooler periods, followed by more warming to give that snow a chance to melt slowly,” said Ryan Connon, a GNWT hydrologist.

“It’s been starting that way. We’re hoping that it’ll finish that way.”

When it gets too hot, too fast, Connon said – such as temperatures not dropping below zero degrees at night – ice jams can form, as melting water lifts ice off river banks and carries it down-river until it hits more solid ice farther north.

That can form a dam – an ice jam – behind which the water rises rapidly.

Connon said that while rain in the river basin can quickly melt snow, so far he has witnessed “a nice, slow start to spring, which we love to see.”

Which communities are at risk?

For the past two years, the GNWT’s list of communities considered to be at risk of spring break-up flooding has included Hay River, the Kátł’odeeche First Nation, Nahanni Butte, Fort Liard, Fort Simpson, Aklavik, Fort Good Hope, Tulita, and Jean Marie River.

On the Peel River, snowpack and water levels are both higher than average, but the GNWT has not indicated that Fort McPherson is at an increased risk of flooding this year.

Emily King, a GNWT emergency management specialist, said on Friday that a community not on the above list can still flood, and communities with historical flood maps should be on high alert throughout spring break-up.

She encouraged residents to develop household emergency plans and identify places they could stay, such as with family or friends, if they need to evacuate.

“This causes the least amount of disruption in terms of care and comfort,” she said.

King also broke down what the GNWT has done to better prepare for break-up this year, such as increasing early engagement with community leaders, updating flood preparedness documents and emergency plan templates for communities, and increasing the number of cots and blankets on hand in case of evacuations. 

While communities’ own emergency management organizations are responsible for preparing, responding, and recovering from emergencies, they can ask for help from regional and territorial emergency management organizations if they exhaust their resources.

The territorial government said it can also help spread the word about community emergencies using its NWT Alert system, and will liaise with the federal government if a community needs more support than the GNWT can provide.