Watersheds: Why water from Alberta floods Saskatchewan

Last week’s rains that soaked both British Columbia and Alberta were felt in Saskatchewan this week.

It’s due to Canada’s watershed system that the effects of a large-scale weather event can be felt across the country.

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Canada’s five main ocean watersheds — the Pacific Ocean, Arctic Ocean, Hudson Bay, Atlantic Ocean and Gulf of Mexico watersheds — all feed into our waterways, delivering water to 594 other watersheds.

And that movement of water that can spread from one province into another, hundreds of kilometres away. Which is exactly what happened this week when Alberta’s rivers became swollen following a four-day-long rain event.

Water west of the Rockies flows toward the Pacific Ocean watershed.

However, 30 per cent of Canada’s water drains into the Hudson Bay watershed, which extends across five provinces, from Alberta to Quebec. It also includes the Northwest Territories and Nunavut.

Interestingly, Natural Resources Canada says that on an average annual basis, Canadian rivers discharge almost nine per cent of the world’s renewable water supply while we have less than one per cent of the world’s population.