Cities across Canada, especially those that depend on alpine snow melt to refill water reservoirs, need to recognize that Cape Town’s water crisis could become their own experience within the century and plan accordingly, scientists warned in a series of CBC reports earlier this month.
“That kind of extreme water shortage hasn’t happened here, but it’s not impossible that it can,” said John Pomeroy, Canada Research Chair in Water Resources and Climate Change, and head of the global water futures program at the University of Saskatchewan.
Pomeroy has spent nearly 15 years studying snowpack levels in Alberta’s Rockies, trying to predict floods and droughts before they happen, and he and his fellow researchers can attest to “the risk that changing weather patterns pose for water supplies,” CBC notes.
“We have been getting rain events even in the winter,” he said, and even in years of record snowfall, like 2017, milder temperatures mean that “the mountain snowpack is melting faster and earlier. As a result, the water is moving through river basins more quickly than in the past and leaving them parched by the end of summer.”
Which meant, CBC states, that last year’s heavy snowfall “wasn’t enough to prevent a drought on the southern part of the prairies.”
Pomery warns that this isn’t just a localized crisis, pointing out “that the snow in the Rockies provides everything from drinking water to irrigation for tens of millions of people across North America.”
Compounding the problem is the swift retreat of glacier ice as the planet warms. “In the past, melt from glaciers would have helped make up for shortages that arose during dry years on the prairies, getting the arid region through the dog days of summer,” writes CBC’s Erin Collins. But that ancient connection between summer snow and valley floor is fast unravelling, said glaciologist Shawn Marshall: “The estimates right now are that about 80% of the ice will be gone by 2100” without sustained efforts to reduce future atmospheric warming.
The combination of mild winters and glacier loss means that multi-year droughts could leave western Canada as thirsty as Cape Town is today. Last year, in the southern Alberta town of Milk River, which has long relied on water from the now nearly-vanished glaciers of Montana, area farmers “were told to stop irrigating their crops after August 3, a move that cost producers as much as C$1 million.”
“The rest of Canada should pay attention, because climate change means traditional weather models no longer apply,” warned Tim Romanow, executive director of the Milk River Watershed Council Canada. “We are the canary in the coal mine, because we already had very precarious water security.”
