Higher than normal stream flow conditions continue in the headwaters of the Rainy River watershed due to the high spring snowmelt runoff in the eastern headwaters working its way through the Rainy River basin, including flows into the Namakan Chain of Lakes and Rainy Lake. The Water Levels Committee (WLC) continues to meet and communicate with the National Weather Service, Ontario Ministry of Natural Resources and Forestry, and dam operators to discuss current basin conditions and forecasts.
As of May 14, Rainy Lake is above the Upper Rule Curve, established for that lake by the International Joint Commission. Similarly, Namakan Lake has been above the Upper Rule Curve since May 8. Water levels in both lakes are expected to continue to rise this week. The dam at Kettle Falls has been fully open since May 2. At Rainy Lake, gates at the International Falls/Fort Frances dam are being opened as quickly as possible to keep pace with flow out of the outlet at the Fort Frances/Ranier railroad bridge. A fact sheet was developed as part of the 2017 Rule Curve Study to explain the natural controls of outflow from Rainy Lake.
As inflow into both lakes remains higher than outflow, the lakes are expected to keep rising. Any additional wet weather could result in a faster rate of rise. Namakan Lake is currently 0.15 m (0.49ft) below the All Gates Open level. Rainy Lake is currently 0.35m (1.15ft) below the All Gates Open level. The All Gates Open level refers to the lake level that dams are required to be fully open. No flood advisories or flood warnings have been issued in Minnesota and the province of Ontario issued a Watershed Conditions Statement stating that the freshet continues on the river systems of Northeast and Northwest Regions.
Updates on dam operations will continue to be provided by the WLC on the IRLWWB’s Water Level Decisions & Data page. This page is also a reference for WLC actions taken throughout the year, including this spring.
Please monitor the National Weather Service Rainy River Basin page and the Province of Ontario Flood page for current flood advisories and warnings.
- International Rainy-Lake of the Woods Watershed Board Water Levels Committee High Water and Flow Advisory (May 5, 2023)
- Factsheet - Control of Outflow from Rainy Lake
Namakan Lake Hydrograph
- Rainy Lake Hydrograph
- Key Roles and Responsibilities for Binational Water Management of Water Levels in the Rainy-Lake of the Woods Watershed
- International Joint Commission - Temporary Supplementary Order, March 3, 2023
Elizabeth Jamieson (Engineering Advisor, Canada)
Abby Moore (Engineering Advisor, United States)
International Rainy-Lake of the Woods Watershed Board
International Rainy-Lake of the Woods Watershed Board Water Levels Committee High Water and Flow Advisory – May 19, 2023 | International Joint Commission (ijc.org)