Upcoming Gate Adjustments – Note Revised Dates of November 23 and 28


Note: Due to unforeseen scheduling conflicts, the gate adjustments will occur on November 23 and 28. It was previously reported that the initial gate movements would occur today, on November 21, but these adjustments have been postponed to November 23.

Anglers and other users of the St. Marys Rapids are advised that the gate setting of the Compensating Works structure at the head of the Rapids will be adjusted on November 23 and again on November 28, 2022. On November 23, the gate setting will be reduced from the current setting equivalent to six gates fully open to a setting equivalent to five gates fully open. The Rapids flow will decrease from 930 m3/s (32,800 cfs) to 730 m3/s (25,800 cfs). Then on November 28, the setting will be further adjusted to a setting equivalent to two gates fully open and the flow will be approximately 250 m3/s (9,000 cfs).

On November 23, the Gates #6 through #8 (near the middle of the structure on the Canadian side of the border) will be adjusted to a setting of 26 cm (10 in) open. On November 28, all eight of the gates on the US side of the structure (Gates # 9 through #16) will also be adjusted to a setting of 26 cm (10 in) open. There will be no change to the setting of Gate #1, which supplies a flow of about 15 m3/s to the channel north of the Fishery Remedial Dike.

The International Lake Superior Board of Control is responsible for managing the control works on the St. Marys River and regulating the outflow from Lake Superior into Lake Michigan-Huron. Under any outflow management plan, the ability to regulate the flow through the St. Marys River does not mean that full control of the water levels of Lake Superior and Lake Michigan-Huron is possible. This is because the major factors affecting water supply to the Great Lakes (i.e. precipitation, evaporation, and runoff) cannot be controlled, and are difficult to accurately predict. Outflow management cannot eliminate the risk of extreme water levels from occurring during periods of severe weather and water supply conditions. Additional information can be found at the Board’s homepage: https://ijc.org/en/lsbc or on Facebook at: https://www.facebook.com/InternationalLakeSuperiorBoardOfControl