Manitoba Hydro advises extreme caution on waterways

Unprecedented rainfall increases flows on Manitoba rivers

This article was published in May 2022 and may be outdated.

Manitoba Hydro urges Manitobans to be careful on and around the province’s rivers and lakes – especially near the utility’s generating stations – as unprecedented precipitation this spring has created record-high water flows and high water levels on some lakes.

“We all need to be careful of the high flows, increased levels and rapidly changing water levels we’re seeing on our rivers, particularly when near our generating stations on the Winnipeg River,” said Manitoba Hydro President and CEO Jay Grewal.

“Please look for and obey all warning signs,” Grewal said. “Property owners and resource users should secure docks and move valuable items like boats to higher ground.”

Winnipeg River levels

Winnipeg River property owners and resource users will see water levels rise over the next 10-to- 15 days by approximately:

  • 1.2 feet upstream of Eight Foot Falls
  • 2.1 feet at Nutimik Lake
  • 1.9 feet at Dorothy Lake
  • 2.2 feet at Margaret/Eleanor Lake
  • 2.3 feet at Sylvia Lake
  • 1 foot upstream of Silver Falls

Flows on the Winnipeg River are high because the Lake of the Woods Control Board (LWCB) was forced to make large increases in outflow from Lake of the Woods and Lac Seul, both of which drain into the Winnipeg River. The LWCB manages the water levels of Lake of the Woods and Lac Seul, Ont. The Winnipeg River is expected to crest in early June.

Lake Winnipeg outflows

Record-high flows on the Winnipeg River are also combining with very high flows on the Red and Assiniboine Rivers and other tributaries to drive up levels on Lake Winnipeg. In response, Manitoba Hydro continues to increase outflows at the Jenpeg Generating Station located at the north end of the Lake Winnipeg.

“What we’re seeing is unprecedented,” Grewal said. “We’ve gone from drought conditions to record flows in less than one year. On the Winnipeg River alone, record flow conditions are occurring across most of the watersheds in Manitoba, Ontario, and Minnesota following heavy precipitation since the start of April, and there is more rain in the forecast.”

Grewal said Manitoba Hydro is steadily increasing outflows at the Jenpeg Generating Station, located where the west channel of the Nelson River flows into Cross Lake (135 kilometres south of Thompson), to manage the level of Lake Winnipeg until it’s back below 715 feet above sea level (ASL).

Water levels on the Nelson River downstream of Jenpeg are forecast to steadily increase over the next month. Manitoba Hydro is communicating with communities that may be affected by the increase in water flow from that facility.

Lake Winnipeg is currently at 714.9 feet ASL and forecast to peak in the 717 feet ASL range by early July. Last year at this time, the lake level was at 712.8 feet ASL. During the last major flood in Manitoba in 2011, the water level on Lake Winnipeg peaked at 716.9 feet ASL around July 7, 2011.

Manitoba Hydro’s Lake Winnipeg control structures include a series of deep channels put in place to allow greater flows out of the lake to overcome some of the constrictions at the natural outflow channel at Warren Landing. The added channels allow an extra 50 per cent more outflow in high water periods compared to the period before the regulation of lake outflows in 1976.

Manitoba Hydro is licensed by the Province of Manitoba to operate Lake Winnipeg for power production when the lake is between 711 and 715 feet above sea level. When the lake reaches 715 feet, the utility must operate its facilities to maximize the discharge from the lake.

One of the primary purposes and benefits of Lake Winnipeg Regulation was the prevention of significant shoreline flooding (as seen in the 1960s and early 70s), as well as improved hydropower production on the Nelson River.

For more information, please contact:

Bruce Owen – Media Relations Officer