Rainy River Basin Conditions Notice – All Gates Open


International Falls, MN, Fort Frances, ON — As noted last Tuesday, 3 June in a release from the International Rainy – Lake of the Woods Watershed Board, recent rainfall brought very high inflow conditions throughout the basin, particularly to the southern tributaries of Rainy River, Vermillion River and the Seine River.

Rainy Lake also rose above its URC, on May 29th, and is now at the all gates open level. At Fort Frances-International Falls, the dam on the Rainy River has flow passing through all turbines and all sluice gates. The last two gates were opened on 6 June at 1200 CDT to ensure maximum outflow from the dam. Both Rainy Lake and Namakan Lake will continue to rise in the near term, and their ultimate peak levels will depend on the amount of rainfall received over the next few weeks.

Dams at both Namakan Lake and Rainy Lake are operated to maintain the lake levels within an operating band, called the Rule Curve, specified by the International Joint Commission. The level of Namakan Lake is above the Upper Rule Curve (URC). The dams at the outlet to Namakan Lake have been fully opened since May 16th. Further upstream, particularly heavy rainfall near the Vermillion River has led to the level at Crane Lake rising by over 40 cm (16 in) since May 30th. Inflow to the Namakan chain of lakes is approximately 20 per cent higher than the outflow capacity of the dam.

The Board suggests that waterfront property owners and users of the system keep themselves updated on basin conditions. Up-to-date information can be found by following the International Rainy-Lake of the Woods Watershed Board’s page on the IJC website, www.ijc.org or call 800-661- 5922 ex. 3.