Schwatka Lake to become a ‘tidal’ water body

Schwatka Lake in Whitehorse doesn’t usually experience high and low tides. But this week, water levels in the lake that serves as a reservoir…

Schwatka Lake in Whitehorse doesn’t usually experience high and low tides.

But this week, water levels in the lake that serves as a reservoir for Yukon Energy Corporation’s hydroelectric plant will be rising and falling.

“What it’s going to look like is that the ice is actually going to be moving up and down — but you’re probably not going to be able to see it move, it’s not that fast,” said YEC spokesperson Janet Patterson on Tuesday.

The reason for all the movement is testing YEC is carrying out with water levels on Tuesday, Wednesday and Thursday.

The goal is to push its power plant to the max and see how much electricity it can generate in winter conditions, said Patterson.

“We need to determine how much water we can let through safely without any flooding,” she said. “This is the only way we can do it.”

For a few hours on each day, YEC will allow about 195 cubic metres of water to flow downstream from the lake into generator turbines at its power plant every second.

The usual amount flowing at this time of year is about 20 per cent lower, or 160 cubic metres per second.

The testing is in keeping with YEC’s long-term plan to use its hydro infrastructure to its maximum efficiency, said Patterson.

“We’re wringing every little bit out of the facilities that we do have,” she said.

There will probably be other side-effects of the test: downstream from the plant on the Yukon River, about as far as Rotary Peace Park, there will probably be a few inches of water covering ice, said Patterson.

Snowmobilers, skiers and walkers who venture onto the ice at Schwatka may notice it is lower than normal and find it difficult to get on top, she added.

“It’s probably safer just to stay off the ice,” said Patterson.

The test will determine how YEC can handle projected increases in power demands in the future from both consumers and the mining industry, she said.

“We want to do everything we can to avoid using diesel (electrical generators). And one of the ways to do that is to not only look at new things we might need to build, but also to look at everything we now have and to make sure it is as efficient as possible,” said Patterson.

Many have long feared an ice jam and melting water could lead to a flood and freeze-up in downtown Whitehorse.

But YEC will be watching everything to control how much water is allowed to flow down the Yukon River, said Patterson.

“We’re not expecting any flooding. We’re going to be really carefully monitoring the area. If anything unusual happens, we’ll stop the test right away.

“I don’t want people to worry that Marwell or Robert Service Campground is going to flood.”