Lake Ontario outflow decreased, water level remains high

The International Lake Ontario St. Lawrence River Board decreased the outflow from Lake Ontario August 8, from 10,400 cubic meters per second (cms) to 9,910 cms. With the lower than maximum outflow for continued commerce, ships should experience easier navigation at the locks.

This new outflow remains a record high for this time of year, with the flow continuing to provide relief from high water levels in Lake Ontario while balancing the impacts downstream. Water levels are expected to continue to decline rapidly into the fall throughout the system and outflows from Lake Ontario will remain high.

Mitigation measures implemented as a result of the high flows will remain in effect until conditions warrant their removal. Any change will be communicated via Seaway Notice. To see the latest notice, click here.

Maritime Editorial