Rivers to flow low based on Rocky Mountain snowpack

Southern Alberta Newspapers Photo by Collin Gallant. LOWER WATER LEVEL: The Trans-Canada Bridge at Medicine Hat is shown above the South Saskatchewan River on Feb. 26. Provincial river forecasters are predicting lower than average water levels this summer based on the snowpack in the Rocky Mountains.

By Collin Gallant
Southern Alberta Newspapers

Alberta Environment is forecasting river levels across the province to be much lower than average this summer based on mountain runoff modelling.

In its February water supply outlook, the ministry states that levels in the Oldman, Bow and North Saskatchewan rivers will likely flow “much below to below average” for the March to September periods in 2025.

The Milk and Red Deer rivers are both expected to be “much below” average, based on an assumption of normal precipitation conditions for the remainder of winter and spring.

The low outlook is due to inconsistent and light snowpack in the Rocky Mountains.

Feeding the Bow River system, 20 of the 23 snowpack monitoring stations registered volumes among the five driest years in more than 50 years of record keeping, while the other three were no better than 10th driest.

In more detailed forecasts, the Oldman River at Lethbridge has a probable summer flow of half to three-quarters a normal year, and is currently only at about two-thirds average levels for late winter.

Probable ranges on in the Bow River basin run as high as 90 per cent of long-term average.

The Oldman and Bow join to form the South Saskatchewan River north of Grassy Lake. There is no specific analysis of that river.

Cypress Hills snow course readings are typically taken in late February and published in March.