Great Lakes Diversions

The major diversions in the Great Lakes basin that affect water levels are diversions into Lake Superior at Long Lac and Ogoki, the Chicago diversion out of Lake Michigan and a diversion between lakes Erie and Ontario through the Welland Canal.

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Great Lakes Diversions

The major diversions in the Great Lakes basin that affect water levels are diversions into Lake Superior at Long Lac and Ogoki, the Chicago diversion out of Lake Michigan and a diversion between lakes Erie and Ontario through the Welland Canal.

Learn More

International Lake Superior Board of Control

The International Lake Superior Board of Control is responsible for regulating the outflow of Lake Superior and managing the control works on the St. Marys River.

About the Board

News Releases

October 8, 2024

Friday, October 11, Gates #9 through #13 will each be lowered to 38 cm open and Gates #14 and #15 will be closed.

October 3, 2024

Anglers and other users of the St. Marys Rapids need to be cautious of the flows and water levels that will be experienced in the rapids in October. The gate setting of the Compensating Works will be decreased from the current setting equivalent to approximately three gates fully open (Gates #7...

September 4, 2024

Anglers and other users of the St. Marys Rapids need to be cautious of the flows and water levels that will be experienced in the rapids in September. On Monday, September 9, the gate setting of the Compensating Works will be decreased from the current setting equivalent to approximately four gates...

On Wednesday, August 7, Gates #7 through #15 will be lowered to a setting of 97 cm open, and Gate #16 will be closed. The St. Marys Rapids flow will decrease from approximately 850 to 640 cubic metres per second. The average St. Marys Rapids flow in August is expected to be approximately 684 cubic...

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