Lake Ontario outflows fourth-highest on record in January despite ice

Posted 29 January 2022 at 9:42 am

Press Release, International Lake Ontario-St. Lawrence River Board

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.

Although flows have been reduced, the outflows remain relatively high compared to the historical record.

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

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.

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.