2016 Release Strategy for Rainy and Namakan lakes

Date

Recent weather conditions have brought warmer than usual weather and above-normal rainfall, resulting in an early start to freshet with rising tributary flows. Under the Rule Curves for Rainy Lake and Namakan Reservoir, prescribed by the Consolidated Order dated January 18, 2001, the refill of these lakes begins on April 1 of each year. The Water Levels Committee of the International Rainy Lake of the Woods Watershed Board recommended on March 17, 2016 that the International Joint Commission (IJC) issue a temporary Supplementary Order to allow for the refill of the lakes to follow the natural inflow pattern that is developing this spring.

According to the US National Oceanic and Atmospheric Administration (NOAA) Spring Outlook, drier than normal conditions are expected in the basin for April through June 2016. By allowing the lakes to begin refilling now, rather than passing excess water to stay within the Rule Curves, less water will be required later to fill the lakes to the May 15 target levels. If dry weather persists through spring and into summer, however, relatively low summer lake levels could still result.

The Water Levels Committee recognizes that permitting higher levels now in both Rainy Lake and the Namakan chain of lakes reduces storage capacity for a short period that could be used to store above-normal inflows in the event that wetter-than-normal conditions develop. With that said, the Water Levels Committee notes that with higher lake levels, the outflow capacity of both lakes increases, so dam owners would be able to pass water at a greater rate if acting aggressively in response to wet conditions, which mitigates the risk posed by storing additional water through early refill of the lakes.

IJC issues temporary supplemental order for outflows from Rainy and Namakan lakes

The International Joint Commission (IJC) issued a temporary supplementary order on March 18, 2016 setting the maximum levels for Rainy and Namakan lakes at levels higher than the upper bounds of the current rule curves until April 15, 2016. The IJC action responds to a recommendation by the Water Levels Committee (Committee) of the International Rainy-Lake of the Woods Watershed Board. The Committee noted that recent weather conditions have brought warmer than usual weather and abovenormal rainfall, resulting in an early freshet. The Committee is concerned that if conditions are dry in April and May, water levels may be low throughout the summer tourist season. The IJC Ordered:

Notwithstanding the terms of the Commission's Consolidated Order dated January 18, 2001, the Water Levels Committee of the International Rainy-Lake of the Woods Watershed Board is authorized, at its discretion, to direct the Companies to target:

 • For Rainy Lake, a lake level no higher than 337.18 m (1106.23 ft) until April 15, 2016;

 • For Namakan Reservoir, a lake level no higher than 340.0 m (1115.49 ft) until April 15, 2016.

After April 15, 2016 the Board and Companies are to resume compliance with the terms of the Commission's Consolidated Order dated January 18, 2001.

A full copy of the temporary supplemental order is available online.

IJC Contacts:

Nick Heisler Ottawa 613-992-8367 heislern@ottawa.ijc.org

Frank Bevacqua Washington 202-736-9024 Bevacquaf@washington.ijc.org