Historically low water level on Bow River concerning, water scientist says

If it seems like the water levelon the Bow Riveris lower than normal this winter, you're right, and the possible implications could be serious, says a top water scientist.

The Bow River's flow level is in the lowest quarter of all observations in the125 years that the Water Survey of Canada has measured the river, according to researcher John Pomeroy, who is based in Canmore, Alta.

He is the Canada Research Chair in Water Resources and Climate Change at the University of Saskatchewan.

"The water level should be about twice as high as it is right now," he said, pointing to exposed sandbars that would normally be submerged.

The reason it's so low has to do with reduced groundwater discharging into the river, he said, which in turn is because the summer of 2021 was so hot and dry and created drought conditions.

If the drought stretches through next year, it could become challenging to supply southern Alberta's irrigation districts and its communities, Pomeroy said.

• WATCH |Atop water scientist discusses what low water levels in Calgary really mean.

The Bow and Elbow rivers are flowing at half the normal rate for this time of year

3 years ago

Duration 4:39

Historically low water levels are thought to be a consequence of last year's hot dry summer and reduced groundwater.

According to Paul Christensen, a senior fisheries biologist with Alberta Environment and Parks, lowflow levels on the Bow have happened before and can occur naturally.

"But I think what we're seeing is that lower flow conditions seem to be occurring more frequently in the past decade than they have for a while," he said.

Christensen says prolonged periods of low flows could result in higher water temperatures containing less oxygen which could be challenging for cold water fish, in particular.

"So when we get those low flow conditions with higher temperatures, it just creates a lot of stress that fish otherwise wouldn't have," he said.

Pomeroy says there would need to be an above normal snowpack this winter and a very rainy spring and early summer to bring the river back into a high level again by next year.

"But this can happen, and it can happen quickly. Many people will remember the flood of 2013," he said.

"So you can have a drought year that flips into a flood year very, very quickly."

And that's a worrisome phenomenon directly related to the warming planet, Pomeroy says.

"Unfortunately, we're bouncing from one extreme to the next. And that is very typical of what we can expect under increasing climate change," he said.

Pomeroy says the targets for limiting global warming set at the recent COP26 conference in Glasgow will not be sufficient to stop the Rocky Mountain glaciers from melting.

And that will create huge water management problems for Alberta in the future, he said.

"Our drought regulator, the glaciers, which melt faster in drought years and accumulate snow in cold years, will be gone. And then we're going to have to prioritize who gets water to drink, who gets water for growing food," he said.

"We have to get climate change under control or our water resources will become more and more fragile."