International Rainy-Lake of the Woods Watershed Board Water Levels Committee Releases the Final 2022 Post-Flood Report

INTERNATIONAL FALLS, MN and FORT FRANCES, ON, Oct. 10, 2023 /PRNewswire/ - The International Rainy-Lake of the Woods Watershed Board (IRLWWB) Water Levels Committee (WLC) released its 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 some of the highest water levels on record. The flood was due to record precipitation in April and May. The intensity and longevity of the spring precipitation caused flows in the tributaries of the Rainy River watershed to remain at high or close to peak levels from late April to mid-June.

The Post-Flood Report focuses on Rainy and Namakan Lakes and covers the following topics: roles and responsibilities shared by the International Joint Commission (IJC), IRLWWB, and WLC within the Rainy River-Lake of the Woods watershed; hydrologic conditions that led to the extreme flooding in the Rainy River basin; activities and decisions of the WLC in 2022; the role of rule curves during flood events and what would have happened if the High Flood Risk Rule Curve (HFRRC) on Rainy Lake was implemented in 2022; and a summary of public engagement and what the WLC heard throughout the flood event and August 2022 public listening sessions.

• A summary report is available and highlights key sections of the full report, including the roles and responsibilities in the basin, a high-level summary of the basin conditions and WLC's actions leading to and after the 2022 flood, results from the what-if scenario modeling, and sources of information during emergency events.
• The IRLWWB ensures compliance with the IJC's Order pursuant to the Rainy Lake Convention, to monitor and report on the ecological health of the Lake of the Woods and Rainy Lake boundary waters aquatic ecosystem, including water quality, and to assist the IJC in preventing and resolving disputes regarding the boundary waters of the Lake of the Woods and Rainy River watershed.
• The IRLWWB's activities are supported by an Industry Advisory Group, a Community Advisory Group, and four committees, including the Water Levels Committee which monitors hydrologic conditions and may provide dam operators with directions for the operation of their discharge facilities to ensure that the rule curves are followed.
• The All-Gates Open level is the lake level at which all gates must be open at the dam. Rainy Lake's All-Gates Open level is 337.90 (1108.6 ft) and Namakan Lake's All-Gates Open level is 341.10 m (1119.1 ft).

• 2022 Post Flood Report: A Report on High Water Levels in the Rainy River Basin
• Summary report - 2022 Post Flood Report
• 2022 Rainy-Lake of the Woods Flooding Frequently Asked Questions
• Key Roles and Responsibilities for Binational Water Management of Water Levels in the Rainy-Lake of the Woods Watershed
• Temporary Rule Curve Order

SOURCE International Rainy-Lake of the Woods Watershed Board