Lake Ontario Flows 4th Highest on Record in January Despite Plenty of Ice


Ice has formed in the critical sections of the St. Lawrence River in the Beauharnois Canal and on Lake St. Lawrence.  Ice began to form in early January along the St. Lawrence River as air temperatures remained consistently well-below freezing for several days. The International Lake Ontario – St. Lawrence River Board (ILOSLRB), through its Operations Advisory Group, monitors ice cover formation in the St. Lawrence River closely.

This year since January 10, 2022, outflows from Lake Ontario have been adjusted (decreased and increased), as conditions have required to manage ice cover formation. Outflow adjustments to support stable ice cover formation occurs most every year.  Several ice booms are also used in the river to assist in ice cover formation. A stable ice cover is important to reduce the likelihood of ice jams that can damage shorelines and cause flooding. A stable ice cover also prevents unconsolidated ice from flowing into and clogging hydropower intakes; ice jams or blockages of hydropower intakes could result in prolonged outflow decreases leading to higher Lake Ontario levels. As ice conditions stabilize, outflows from Lake Ontario will be increased in accordance with the rules of the plan.

Although flows have been reduced, the outflows remain relatively high compared to the historical record. The average Lake Ontario outflow for January 2022 is currently the 4th highest on record since 1900 (following 2020, 2021, and 1987), and the January mean Lake Ontario level is the 15th highest on record since 1918.

Ice conditions continue to be closely monitored. The Board will make outflow adjustments as necessary and share updates and information.  The operational outflow adjustments are consistent with and accounted for in the design of the regulation plan as part of the I Limit. To learn more about the importance of ice formation and the Board’s role in managing it, please refer to Learning Module 5 and frequently asked questions 2.7 and 4.8.4.

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, and more detailed information is available on the website at Frequently asked questions are available at


Bryce Carmichael: (513) 418-8562           

Sarah Lobrichon: (613) 794-8592

Or by email :

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 adjust 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.