Water Levels Committee Targeting Lower Rule Curve for Rainy Lake

Date

International Falls, MN, Fort Frances, ON – On June 15, the Water Levels Committee of the International Rainy-Lake of the Woods Watershed Board directed the owners of the dam at International Falls-Fort Frances (Boise Paper, H2O Power LP) to target the Lower Rule Curve level for Rainy Lake by July 1, and to continue targeting the Lower Rule Curve until further notice.

The Rule Curves are the target range of lake levels established by the International Joint Commission (IJC) in 2000 to best balance the many interests in the system. Under normal circumstances, the dam owners are responsible for adjusting flows through the dam to target the middle portion of the Rule Curve range. The decision to target the Lower Rule Curve was made in order to reduce the risk of having the lake exceed the top of the Rule Curve range. Recent rainfall has increased the rate of water flow into Rainy Lake which is now in the upper-normal range for mid-June.

While there is no indication of increased risk of high water conditions based on current conditions and forecasts, additional caution is being exercised due to the temporary closing of two of the fifteen spill gates at the dam for refurbishment and the fact that June and July are statistically the months with the greatest rainfall. However, should extremely high inflows develop, the possibility remains of the lake rising above the Rule Curve range due to the physical limits on outflow from Rainy Lake.

The Lower Rule Curve target water level is 12.5 cm (4.9 in) lower than the middle of the Rule Curve range.