How high could water levels get in southern Yukon? It now depends a lot on rain

Yukoners wondering just how high water levels could get this summer should start looking to the skies. 

Though flood warnings remain in place for the Southern Lakes, Lake Laberge, and the Yukon River at Carmacks, Kat Hallett, a spokesperson for the government of Yukon, said one source of rising water appears to be running out. 

"What we've noted over the last few days is that rates of rise are decreasing a little bit," she told host Elyn Jones on CBC Radio's Yukon Morning on Tuesday. 

"What this indicates is that the high elevation snowpack is beginning to be depleted, but we know that rainfall is going to be a big source of uncertainty."

Hallett said that though water levels continue to rise as the snow melt tapers off, it's the "amount and timing of rain events" that will ultimately determine how much higher water levels could go — and how much damage could ensue.

Typical weather conditions will lead to gradual water dropping

Answering questions for a recent Yukon University article about the flooding, Dr. Benoit Turcotte, a senior research professional in hydrological processes, came to the same conclusion. 

He said the flooding Yukon has seen so far was caused by a "rare combination of a record snowfall in southwest Yukon, a late spring snowmelt with some rain, and high air temperatures that caused the snow to melt relatively suddenly." 

Now, though, "the bulk of the snow melt is behind us." 

Turcotte said that as long as the remainder of the summer sees typical amounts of rain and heat, bodies of water will see a "limited rise" of about 15 centimetres, followed by a gradual decline. 

In those kinds of typical weather conditions, Yukoners should not be worried about light rain or short bursts of intense rain, he continued, "because the ground is now very dry at many locations and can absorb water." 

However, Turcotte notes that very wet conditions in the next few weeks could lead to a very different outcome. 

City of Whitehorse prepares

In addition to the other warnings and advisories, there is also a high streamflow advisory on the Yukon River at Whitehorse.

At Monday's council meeting, acting city manager Valerie Braga told councillors that the city is "taking the situation quite seriously."

She said they've decided to partially open the emergency operations centre, and are now considering next steps and what supplies would be needed if the water gets higher.

The Bert Law bridge has also been closed due to high water levels, Braga said. 

"We've got to prepare for a wide range here. We may get by with not much more than it is now, but it could be a lot more than it is now," commented Coun. Dan Boyd. 

"We're getting the floods, we're seeing the fires, people have been asking when the locusts are going to come," said Coun. Steve Roddick. 

"This has become an almost biblical level of climate extremes we're seeing here."  

Canadian Forces begins work

Tuesday is also the first day of work for the approximately 100 Canadian Forces members who've been brought to Yukon to help with flood mitigation efforts.

They were sent to Yukon, most of them from a base in Edmonton, after the territory's government made a request for help from the federal government. 

"The majority of [their work] will be filling and moving sandbags, assisting people affected by the floods, conducting check-ins on the residents and on properties that are affected by the flooding," said Major Alexander Trousdale, the Yukon detachment commander for Joint Task Force North. 

He said they will also be able to assist with any evacuation orders, should the need arise.