REGIONAL-Abnormally high levels of precipitation have had eyes in Crane Lake and Kabetogama focused on rising lake levels this past week as dams in the Rainy River Basin opened their gates to try to stabilize the situation. The rising water comes just two years after record flooding in the basin.
According to a summary report issued by the Duluth National Weather Service office on Sunday, 5.44 inches of rain fell in International Falls between April 25 and May 25, the fourth-highest amount for that period and almost three inches above normal. On the eastern end of the basin, rain in Ely from May 1 to May 26 was 4.10 inches, or 166 percent above normal.
The higher than projected inflows were already having an impact on Namakan and Rainy lakes even before the latest rains. Back in March, the water levels committee set lake level management targets based on an analysis of drier than normal conditions, and historically low snowpack, and seasonal forecasts indicating equal chances of above or below normal precipitation. A review in late April noted that early spring precipitation had been below normal and that drought conditions were between abnormally dry and moderate drought. The above average precipitation in May threw a wrench into that analysis as lake levels began trending toward the top of their management rule curves by early May.
Last Tuesday, May 21, the water levels committee indicated they were “taking action to manage anticipated high inflows while considering impacts across the basin.”
According to a release from the committee, logs were pulled from the Squirrel Falls dam on May 21 and more logs were pulled from the Kettle Falls dam on May 22, but Namakan Lake still rose above its rule curve on May 23 due to the increasing inflows. Daily outflow increases began at Rainy Lake on May 18, with two larger increases occurring on May 21, the same day Rainy exceeded its rule curve. The committee reported that all hydropower turbines were running and gate openings began on May 23.
The weather service noted in its Sunday briefing that inflows still slightly exceeded outflows on Rainy Lake, with both on the rise, while for Namakan and Kabetogama inflow was meeting outflow, helping to stabilize lake levels. Because water moves slowly through the basin, the weather service advised that levels will be slow to come back down.
The committee is managing outflows to bring both lakes back to the middle of their rule curves by mid-June, assuming the weather cooperates.