What low water levels in Edmonton could mean for fish this winter

With multiple bodies of water under water shortage advisories after a dry start to the month, some fish in Edmonton could be facing a tough winter.

Clearwater River, Sturgeon River and the Whitemud and Blackmud creeks currently have water shortage advisories. These are imposed when stream flows or lake or reservoir levels are lower than normal.

That can have an impact on aquatic wildlife, said Mary Ellen Shain, a senior watershed planning coordinator at North Saskatchewan Watershed Alliance.

She said low water levels can also mean there are reduced oxygen levels — even before a stream or lake gets seized up by ice. The fish and other creatures in those bodies of water will be using up what oxygen is available to them going into the winter.

"If there isn't enough to carry them through the winter, we will end up with fish kills," Shain said.

She said while the province has a history of drought and aquatic ecosystems are adapted to go through water level fluctuations, chronically low water levels may make a body of water uninhabitable for fish. Low water levels also cause concentrations of contaminants to rise. 

This year the North Saskatchewan River at Edmonton was 11th lowest it has been since 2000 — average, in other words — according to a spokesperson from Alberta Environment and Protected Areas. 

Warm and dry month

November has been a drier and warmer month than average, said Terri Lang, a meteorologist at Environment and Climate Change Canada, though it did not smash any records.

"If we look at the record temperatures for the Edmonton area, we're not even cracking the top five," she said.

But the month has been really dry, she said.

"For the month of November, there's been no precipitation whatsoever recorded at the city centre station at Blatchford." 

On Nov. 1, Edmonton airport recorded just enough precipitation to wet the ground, she said. 

"So, really no precipitation so far in November, which I would say is unusual," Lang said, noting that the month is generally a drier month for Edmonton.

El Niño effect

This winter in Edmonton may be warmer and drier than an average winter due to El Niño, Lang said. 

El Niño is when the surface water off the coast of South America gets warmer than average. 

In Western Canada, El Niño causes the jet stream to shift further north. With it goes moisture-bearing precipitation patterns, Lang said, resulting in a snowier winter in northern Canada and less snow in more southern areas.

"It doesn't mean it won't snow, it doesn't mean it won't get cold," Lang said. 

"It just means, on average, the winter is supposed to be warmer than average, and drier than average."

Lang said the warmer air could mean Edmonton gets some of its winter precipitation in the form of rain rather than snow.