Parks Canada has banned swimming at the main beach in Prince Albert National Park.
The Monday evening storm knocked out power affecting the sanitation system in Waskesiu. As a result, the lift stations were overloaded and sewage backed up into Waskesiu Lake.
The amount of sewage leaked was small, but swimming at the main beach will be banned until the water is tested and comes back clean.
All other beaches around the town site remain open for recreation.
