High risk of flooding around Dawson City, Yukon, as late spring thaw arrives

The latest ice breakup forecast for Yukon suggests there may be some flooding in the Dawson City area this spring, though not likely in town.

"We assess the flood risk as low for Dawson City proper, the town itself, because it is protected by the dike," said Anthony Bier, the Yukon government's acting senior hydrologist.  

It's been a cool spring so far in the Dawson area, and a lot of snow fell over the winter. The amount of snow on the ground — called the snowpack — is higher than it usually is, meaning more water hitting the rivers once things start melting.

Water levels began rising on April 21, according to the territory's first ice breakup forecast of the year, but the late thaw makes it hard to predict what will happen.

That forecast, issued Wednesday afternoon, said if water flow increases rapidly, ice could jam up on both the Klondike and Yukon rivers. With warmer weather on the horizon, there's a high probability of that happening on the Klondike. Overnight lows are expected to stay above freezing starting Sunday.

Bier says the Klondike River is more likely to cause flooding in areas that are typically more at risk, such as Rock Creek and the Tr'ondëk Hwëch'in farm.  

The potential for ice jams to cause flooding on the Yukon River, meanwhile, is considered moderate.

Bier says a lot depends on the weather. Ideally, the Klondike region will see a "slow and steady" temperature increase over the coming days, he says, with some sunshine to melt the ice and little precipitation.

"Unfortunately, the sunny part doesn't seem to be in the forecast, at least for the next five-ish days, but at least the temperature seems to be in our favour," he said.

On the Yukon River, the forecast predicts breakup happening after May 4 unless temperatures soar. Starting next week, there's a moderate chance of ice jams causing a sudden rise in water levels.

Bier says the Klondike valley saw a more "dynamic" freeze-up last fall, resulting in some areas where ice is thicker and now more prone to cause jams during break up.

"So we're starting from a higher-than-normal flow, and we know we potentially have that more resistant ice cover," he said. 

Hydrologists have cameras set up to monitor the water levels in the coming days. Once the ice starts to break, Bier says they'll travel up to Dawson to watch it more closely, including with aerial surveys.

Bier says they're also watching other areas of the territory, including around Ross River and Carmacks. He says the flood potential in those areas looks "pretty low" right now.