Residents of the Rainy River watershed in Ontario and Minnesota expressed different preferences for new rule curves during a series of public hearings held by the IJC from Aug. 16-18. The hearings were designed to gather public input on the International Rainy-Namakan Lakes Rule Curve Study Board’s draft recommendations to the Canadian and US governments, and the IJC’s position on the proposals.
Rule curves are the upper and lower water level ranges that water managers try and keep within throughout the year. Generally speaking, the aim is to allow the lakes to fill in the spring for a number of interests – including recreation, hydropower and ecological needs – and that keep water levels up through the summer and fall months, and then draw the water levels down in the winter. The last changes to the Rainy-Namakan rule curves took place in 2000 with the requirement that they be revisited in 15 years; the study board was appointed by the IJC in 2015.
The study board released a series of draft changes and recommendations to the rule curves and how water levels are managed, notably adjustments to the curves to improve ecological outcomes for muskrats and fish (and in turn bring bad news for invasive cattails, as more muskrats should be able to bring them under control). These changes entail adjusting the timing of the water drawdown on Namakan Lake and including different rule curves in case of high flood risk springs on Rainy Lake (known as alternative C). Another proposed adjustment to the 2000 rule curves, known as alternative B, is essentially the 2000 rule curves with the addition of conditional springtime high flood risk rule curves on Rainy Lake.
Residents of Rainy Lake were largely supportive of alternative C, which is the option the IJC is supporting. That proposal should reduce flood risks on Rainy Lake and provide other benefits to both lakes. Residents around Namakan and Kabetogama lakes were generally supportive of new rule curves but raised concerns about the timing of the draw down on Namakan Lake under alternative C. The IJC is reviewing those concerns, which include worries about walleye reproduction and flood risks. Study board Co-Chair Matt DeWolfe concluded in a summary to the Commission that there doesn’t seem to be any increased flood risk under alternative C, and the study board more broadly concluded in the same summary that the plan should increase spawning for walleye, northern pike, cisco and lake whitefish.
Other issues raised at the public meetings were the impacts of climate change on the basin – such as more extreme variability in rain events, ice leaving the system earlier, and more pollen. Attendees also discussed the presence of three “pinch points” that serve as locations where water flow is constricted, such as the Pither’s Point constriction upstream of the Rainy River and the old Koochiching Falls area upstream of the dam on Rainy Lake. There are also concerns that manmade structures such as a rail bridge could be pinch points and cause flooding if debris falls into the water passages. Residents wanted to see the impacts of easing these constrictions studied further for their impacts on flooding risks and dam capacities, as well as the ecological repercussions, feasibility and other dangers. Such a study is outside of the IJC’s authority without being directed by the Canadian and US governments, but according to the Commission’s position paper produced for the public meetings, the IJC plans on notifying the governments about that concern.
Those who attended the public meetings said they were pleased with being included in the discussions for new rule curves, and supported continued local input for decision-making. The IJC will review all comments provided by the public, and will consider them when forming its final order by the end of the year.