Update on Kootenay Lake Water Levels and Conditions Summer 2026
The International Kootenay Lake Board of Control reports that Kootenay Lake levels remain in compliance with the International Joint Commission’s (IJC) 1938 Order of Approval which sets the limit for maximum lake levels.
Currently, Kootenay Lake is experiencing low lake levels and inflows due to above average temperatures and below average precipitation in the basin.
Kootenay Lake inflows peaked at 86,100 cubic feet per second (2,438 cubic meters per second) on May 28 and have decreased to 20,300 cfs (575 cms) as of July 28. Outflows from Kootenay Lake peaked at 61,300 cfs (1,736 cms) on June 2 and have since decreased to 18,100 cfs (513 cms) as of July 28. Lake outflows are controlled by the Corra Linn Dam or by the natural constriction of the lake at Grohman Narrows.
Kootenay Lake peaked at 1,748.16 feet (532.8 m) on June 1 at Queens Bay on the main body of the lake and is currently down to 1,743.6 feet (531.45 m) at Queens Bay and 1,743.3 feet (531.36 m) at Nelson. The 1938 Order specifies that once the lake elevation falls below 1743.32ft (531.36 meters), as measured at the Nelson gauge, it should be held below this elevation until August 31. On July 8, Kootenay Lake at Nelson dropped below 1743.32 feet (531.36 meters) and the lake level must remain below this elevation until the end of August.
Starting September 1, the Rule Curve for Kootenay Lake level will increase to 1,745.32 feet (531.97 meters) as measured at the Queens Bay gauge for compliance measurements.
Figure 1. Kootenay Lake levels at Queens Bay (green) and Nelson (orange), lake outflow control by Corra Linn (pink) or Grohman Narrows (purple), and the International Joint Commission 1938 Order of Approval Rule Curve for 2026 (red). Credit: FortisBC (data) and Environment and Climate Change Canada (plot), 2026.
Quick Facts
The International Kootenay Lake Board of Control is responsible for overseeing that FortisBC operate Corra Linn Dam, such that Kootenay Lake levels are in compliance with the International Joint Commission 1938 Order of Approval Rule Curve.
The Kootenay Lake Visualization Tool is available to the public to better understand the complexities, competing interests, and physical limitations in the management of Kootenay Lake’s water levels.
The Kootenay Lake Board of Control is reviewing the 1938 Order of Approval. Due to this work, there were two in-basin meetings: in Nelson, BC on June 2nd, and in Bonners Ferry Idaho, June 3rd. Additional information on the Order Review is posted at this location.
Video recordings of the meetings have been posted to the board website, while meeting minutes will be posted in September following the boards next quarterly call.
The board is led by Canadian Section Chair Joel Trubilowicz, US Section Chair Col. Kathryn Sanborn transitioned out of her role on July 17, and has been replaced by Col. Eli Adams, who has started his three-year command of the USACE Seattle District.
Canada, the United States, and Ktunaxa Nation requested the International Joint Commission’s assistance in addressing transboundary water pollution in the Elk-Kootenai/y Watershed. This topic is outside of the responsibilities of the Kootenay Lake Board of Control. More information can be found here: International Elk - Kootenai/y Watershed Water Pollution Study | International Joint Commission (ijc.org)
You may contact the board through the Contact form on its website.
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Contacts
Sonja Michelsen, US Secretary
Martin Suchy, Canadian Secretary
