Will Yukon's record snowpack lead to floods? That depends on the weather

Record snowpack levels across much of the Yukon increase the chances for flooding but ultimately, it's the weather in the next few months that will determine whether the territory will experience flooding again this summer.

Holly Goulding, a senior hydrologist with the Yukon government, said an April 1 snowpack survey shows that eight of the 11 watersheds it monitors have the highest snowpack estimates on record, going back to the 1980s. 

Snowpack estimates in the other three watersheds didn't set records but are higher than their median average.

Goulding said weather that leads to rapid melting in the next few months could lead to flooding.

"That includes things like localized runoff so that, you know, snowmelt-impacting properties and infrastructure at a very local scale. And that will be a concern across the territory," she said.

Last summer, rapid snowmelt caused serious flooding, eventually spurring the territorial government to declare a state of emergency for the Southern Lakes and Lake Laberge areas. Some Yukoners were forced from their homes and the Canadian military was posted in the territory for months to help shore up lakefront properties

Goulding said that how the ice breaks up and whether or not it forms ice jams in the next few months will also determine whether or not rivers flood. 

"That's impacting river communities, in particular Dawson, Rock Creek, and Old Crow where we have historically seen the worst ice jam flooding," she said.

Goulding said snowpack levels on Marsh Lake, which was particularly hard hit last year, is lower this year.

"It's a better outlook," said Goulding, adding that the snowpack estimate in the area southeast of Whitehorse, the Upper Yukon River Basin, is at 145 per cent above the average median for the area this year, compared to 196 per cent last year.

She said gradual warming early in the season, with weather alternating between warmer and cooler, would be ideal for the snowpack to melt more slowly, and avoid flooding.

She said the next snowpack survey, which will take place on May 1, will indicate how melting took place in April and provide a better sense of the potential for flooding.