Weather system could bring up to 75 mm of rain to southeastern Manitoba

High waves and 75 millimeters of rain could swamp communities along Manitoba's largest lakes, threatening over 50 communities and provincial parks.

Overland flooding warning expanded to include south-central Manitoba

An aerial image shows the flooding from the Red River outside of Morris, Man., which is protected by a ring dike, on May 11. The province is again issuing warnings as rain and winds threaten parts of southeastern and south-central Manitoba. (Trevor Lyons/CBC)

High waves could swamp communities along some of Manitoba's largest lakes as another storm threatens to bring up to 75 millimetres of rain to the southeastern quadrant of the province, the province warns.

The province expanded its overland flooding warning Monday to include south-central Manitoba and municipalities, First Nations and parks along four lakes.

More than 50 communities and provincial parks along the southern basins of Lake Winnipeg, Lake Manitoba, Dauphin Lake and Lake Winnipegosis are at risk of heavy waves as high winds drive up water levels.

Water levels at Lake Winnipeg and Dauphin Lake are already high. The storm could bring winds  of up to 100 km/h, and that could drive up water levels on all four lakes by five feet, Transportation and Infrastructure Minister Doyle Piwniuk said Monday in a news briefing.

With severe winds, Lake Winnipeg, which is already at  715.8 feet above sea level, could exceed 720.8 feet. 

Any properties along Lake Winnipeg's south basin at elevations lower than 723 feet could be affected.

Lake Manitoba levels could reach 817.2 feet at the southern basins, exceeding the flood level and could affect low-lying areas and properties. However, most properties at the south shore are protected to 817.5 feet or higher.

Dauphin Lake is already one foot above flood stage, and properties along the souther basin could be impacted by flooding.

Piwniuk said the province has 1.5 million sandbags and about 8,000 super sandbags at the ready. 

The updated forecast shows that areas along the western portion of the Red River Valley could now be affected with heavy rain starting Monday evening and continuing until Tuesday morning. 

Environment Canada on Monday issued a special weather statement warning of the possibility of flash flooding and water-related washouts. 

Province shuts park, issues advisory 

The province announced a number of provincial park closures and advisories as a result of the incoming weather system, citing a risk to people's safety. It ordered Rainbow Beach Provincial Park on the south basin of Dauphin Lake and its campground closed until at least June 2. 

Several other closures were announced:

  • Boat launches are closed at Lundar Beach, Patricia Beach, Rainbow Beach, Watchorn and Winnipeg Beach.
  • Camp Morton Provincial Park campground has a partial closure of sites due to risk of overland flooding until at least June 2.
  • Grand Beach Provincial Park parking lots 2 through 5 are closed on the west beach.
  • Lundar Beach Provincial Park campground has a partial site closure due to risk of bank erosion, overland flooding and falling trees until at least June 2.
  • St. Ambroise Beach Provincial Park has advised seasonal campers in the leased campground to remove their units and secure assets.
  • Watchorn Provincial Park campground has a partial site closure due to risk of bank erosion and overland flooding until at least June 2.

Park visitors should check for road closures and potential detours before travelling to parks, the province said.