Extreme water levels not expected along St. Lawrence River

This diagram from the International Joint Commission's Lake Ontario-St. Lawrence River Board shows the current outflow this year (dark blue line) from Lake Ontario into the St. Lawrence River compared to the long term average (grey dotted line). The board says water levels in the St. Lawrence River will peak well below the flooding events of 2017 and 2019. (IJC via Newswatch Group)

CORNWALL, Ont. – The international body overseeing water levels on Lake Ontario and the St. Lawrence River says levels will peak “well below” the flooding events of 2017 and 2019.

The International Lake Ontario-St. Lawrence River Board released a statement Tuesday saying things are improving as a result of “much more moderate weather and water supply conditions” this year.

While Lake Ontario’s water level is still higher than average, the board says “pushing beyond” Plan 2014 and moving more water downstream “beyond those previously perceived as feasible” during winter and early spring have paid off.

The high outflows are able to continue, partly because the Ottawa River already peaked earlier than normal this spring and “conditions downstream can now handle additional flow.”

But the board is still standing behind the often-criticized Plan 2014 saying that “no regulation plan can be designed to address every imaginable and sustained extreme weather event and provide total protection for all water uses throughout the system at all times.”

As for this summer, the outflow of 10,400 cubic meters per second (367,000 cubic feet per second) will likely not happen like in summers in previous years. That’s because the water levels are lower, meaning a high outflow would cause more water turbulence and cause a risk to commercial and recreational ships in the St. Lawrence River.