Lake Winnipeg - Water Conditions

Water Conditions

Because of its long, narrow shape, the lake exhibits a variety of interesting wind and wave effects, including temporary water level rises of up to one metre in height at its southern shore, a process called seiche. This occurs when prevailing northerly winds blow along the length of Lake Winnipeg, exerting a horizontal stress on its surface. Surface waters move in the direction of the wind and pile up along the leeward south shores.

Furthermore, water depths are known to be extremely variable at the south end of the lake. Many of the recreational beaches on the southern end of the lake feature rustic, seasonal piers for swimmers. It is not uncommon to be able to walk off the end of one of these piers one day into more than waist-deep water, then return a few days later to the same spot to find the water only ankle deep, or even exposed sand.

Setups greater than 1 m above normal lake levels have been recorded along many of southern Lake Winnipeg's recreational beaches, and the associated high waves with their uprush effects have caused considerable storm damage, backshore flood and shoreline erosion. The highest setups occur in the fall, when the northerly winds are strongest.