DRAFT 2022 Post Flood Report: A Report on High Water Levels in the Rainy River Basin
In the spring and summer of 2022, the Namakan Chain of Lakes and Rainy Lake reached the highest water levels on record. The flood was a natural disaster that lasted for many weeks. Rainy Lake reached record-breaking water levels, and Namakan Lake ranked as the third highest on record. Since 1949, the International Joint Commission (IJC) has employed rule curves to regulate water levels on Rainy and Namakan Chain of Lakes. The Water Levels Committee (WLC) of the International Rainy-Lake of the Woods Watershed Board (IRLWWB), monitors hydrologic conditions throughout the year and provides dam operators, which are currently H2O Power in Canada and Boise Paper in the United States, with directions for the operation of their discharge facilities to ensure the rule curves are followed.
This report provides a review of the conditions which led to the high-water event in 2022, a summary of WLC actions, and answers questions raised by the public. Additionally, the report includes an analysis of what would have happened if the High Flood Risk Rule Curve (HFRRC) had been employed starting March 10, 2022.