High water levels in St. Lawrence River expected this winter

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By Nick Seebruch
High water levels in St. Lawrence River expected this winter
Cornwall's Moses-Saunders Dam (Nick Seebruch/ Seaway News).

CORNWALL, Ontario – The International Lake Ontario – St. Lawrence River Board, the governing body that dictates outflows into the St. Lawrence River from Lake Ontario are cautioning that water levels near Cornwall could be unusually high this winter.

“High water levels are anticipated when ice begins forming at critical areas of the St. Lawrence River.  When ice begins to form, the International Lake Ontario – St. Lawrence River Board must reduce outflows through Moses-Saunders Dam to help create a stable ice cover on the river.  Flow management during ice formation helps to prevent ice jams in the St. Lawrence River that can restrict flows and cause local flooding,” reads a press release from The Board.

The higher water levels are expected to be seen in the area immediately west of Cornwall.

“The reduced outflows cause levels of Lake St. Lawrence, immediately upstream of the dam, to rise temporarily.  The largest and most rapid increases occur closest to the dam, in the area just west of Cornwall, ON and Massena, NY.  These effects are reduced moving upstream and tend to be negligible beyond Iroquois, ON and Lisbon, NY,” The Board states. “With Lake Ontario expected to remain well above average for at least the next several weeks, this will also contribute to higher levels of Lake St. Lawrence this winter.  The Board is therefore advising residents of Lake St. Lawrence to prepare for the potential of unusually high levels this winter.”

The Board went on to say that over the winter it would explore opportunities to deviate from their prescribed management plan to help prevent flooding come the spring.

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