The International Lake Ontario – St. Lawrence River Board Plans to Assist Boat Haul Out on Lake St. Lawrence the Second Weekend in October
The current water level on Lake St. Lawrence at Long Sault Dam is approximately 73 meters (239.50 ft.). The International Lake Ontario-St. Lawrence River Board will temporarily reduce outflows from Lake Ontario to increase water levels on Lake St. Lawrence the second weekend of October. This effort will provide marinas and shoreline dock owners an opportunity at the end of the season to remove recreational boats more easily. The Board will temporarily reduce outflows through the Moses-Saunders Dam for a 72-hour period from noon on Friday, October 8th through noon on Monday, October 11th to raise water levels on Lake St. Lawrence. Based on the current forecast, Lake Ontario outflows are expected to be temporarily reduced by approximately 250 m3/s (8800 cfs) to reach a target water level of about 73.10 meters (239.83 ft.) on Lake St. Lawrence at Long Sault Dam during the holiday weekend in October.
“Decreasing the outflow through the dam will cause water levels immediately upstream on Lake St. Lawrence to rise. However, there will be a temporary decline in water levels downstream of approximately 10 to 15 cm (3.9 to 5.9 in.) at Lake St. Louis and Montreal”, said Mr. Steve Durrett, United States Co-Chair of the International Lake Ontario-St. Lawrence River Board. The Board will continue to monitor weather forecasts, water supply conditions, and refine this strategy as necessary in the coming weeks. The Board has been operating under regulation plan flow since July 17th. The discretionary flow reduction is permitted by Plan 2014 and considered a minor deviation. “It is important to recognize that wind conditions could impact water levels on Lake St. Lawrence that may help or hinder boat haul out”, said Mr. David Harper, Canadian Co-Chair of the International Lake Ontario-St. Lawrence River Board.
Water levels on Lake Ontario are expected to increase by less than a third of a centimeter. As required by the IJC’s Directive, the small amount of water that will be stored on Lake Ontario during this temporary flow decrease will be completely offset by an increase in flow later in October. The 4 cm (1.6 in.) of water that was stored on Lake Ontario during the major (low Criterion H14) deviations (undertaken from May 28 through July 16, 2021) will be retained on Lake Ontario through mid-October, and this will provide a small benefit to recreational boaters in the Thousand Islands and upper St. Lawrence River.
Information on hydrologic conditions, water levels and outflows, including graphics and photos, are available on the Board’s website and posted to the Board’s Facebook page at https://www.facebook.com/InternationalLakeOntarioStLawrenceRiverBoard, and more detailed information is available on its website at https://www.ijc.org/en/loslrb.
Bryce Carmichael: (513) 418-8562
Sarah Lobrichon: (613) 794-8592
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The International Lake Ontario-St. Lawrence River Board ensures that outflows from Lake Ontario meet the requirements of the International Joint Commission's Orders of Approval. Under any regulation plan, the ability to regulate the outflow from Lake Ontario does not mean that full control of lake levels is possible. This is because the major factors affecting water supply to the Great Lakes, precipitation, evaporation, and runoff cannot be controlled, and are difficult to accurately predict.