Calgary monitoring river levels amid below-average mountain snowpack levels
The City of Calgary is keeping a close eye on water levels for several reasons this spring, including hot, dry weather and below-average mountain snowpack levels.
"We've seen a 30 per cent increase in demand above normal for this time of year," said Nicole Newton with the City of Calgary.
"We have started to increase the levels of the reservoir in anticipation to manage our water supply that will get us through the wintertime."
John Pomeroy is the Canada research chair in water resources and climate change at the University of Saskatchewan.
He says the snowpack also started melting earlier than he's ever seen.
"About six weeks early," he said.
Even along the continental divide, where winter snows historically lingered until July most years, there is very little, if any, snow left.
It means rivers such as the Bow and the Elbow will get the majority of their volume from groundwater and any rain that falls.
The Bow River generally hits peak runoff in mid-June, but this year it peaked about three weeks ago – something seen across most of the province.
"Their flow has dropped in half for the last 10 days, and it's now in some of the lowest flows ever measured this time of year," Pomeroy said.
Glaciers and lingering snow act as drought insurance for the Prairie provinces, ensuring a volume of cool water continues to flow, even if rain doesn't fall. However, glaciers have been retreating for roughly a century, and melting has accelerated rapidly over the past 30 years.
"In fact, very disturbingly, last month we published a paper showing predictions for the Bow and Elbow rivers for the end of the century under climate change if we don't do anything about climate change," Pomeroy said.
"It's kind of a worst case scenario, and what we've showed for the end of century years looks a lot like this year."
Even since it began to melt away, the Athabasca Glacier one of six outlet glaciers coming off the Columbia Icefield – often held snow on its surface until into July.Now its bottom three kilometres are all snow-free and a massive volume of ice has already melted away.
Already this year, 1.7 metres of ice has melted off the top of the Athabasca – the total volume lost is roughly the equivalent of 1,122 Olympic sized swimming pools.
"We may have crossed a tipping point for glaciers like the Athabasca," said Pomeroy. "We're almost certainly in for record glacier melt this year - even higher than previous years."