The International Lake Ontario-St. Lawrence River Board will begin its temporary reduction of outflows from Lake Ontario to increase water levels on Lake St. Lawrence over the Thanksgiving weekend.
The water level increase is intended to provide marinas and shoreline dock owners on the shoreline of Lake St. Lawrence help with their seasonal recreation boat haul-out. The outflows will be reduced from noon on Friday, Oct. 8 and are planned to stay that way through noon on Monday, Oct. 11.
According to the board, Lake Ontario outflows will be temporarily reduced by approximately 600 m3/s to reach a target water level of about 239.83 ft. or 73.10 meters on Lake St. Lawrence at Long Sault Dam this coming weekend.
The water level on Lake St. Lawrence at Long Sault Dam was approximately 72.86 meters or about 239.04 ft. on Wednesday morning, board officials said.
"This is a discretionary action that the board considers pending current and forecast water levels throughout the Lake Ontario-St. Lawrence River system at the end of a given boating season," said Steve Durrett, United States co-chairman of the International Lake Ontario-St. Lawrence River Board, in a prepared statement.
The forecast weather conditions include northeasterly winds which may create less than ideal conditions and may prevent water levels from reaching their target, according to the board.
Lake Ontario water levels are expected to be less than one centimeter higher than usual as a result of the boat haul-out assistance. There will be a temporary decrease in water levels at Lake St. Louis and Montreal of about 30 cm, which the board said will bring water levels close to the long-term seasonal average.
The water levels in Lac Des Deux Montagnes and other locations further upstream and along the Ottawa River will not be affected by these temporary outflow and water level changes this weekend.
As required by the IJC'sDirective, the small amount of water that will be maintained on Lake Ontario during this temporary flow decrease will be offset by an increase in flow later in October.
The 4 cm of water that was maintained on Lake Ontario during the major deviation that was undertaken from May 28 through July 16, 2021 will be retained on Lake Ontario through mid-October.
The discretionary flow reduction is permitted by Plan 2014 and considered a minor deviation, board officials said.
"Lake St. Lawrence was created during the construction of the dam and seaway in the 1950s, and water levels on the lake are directly impacted by regulation outflow and Treaty requirements," said David Harper, the boar's Canadian co-chairman, in a prepared statement.
The board encourages all boaters to be mindful of weather conditions and continue to use safe boating practices.
Jessica Munro, Local Journalism Initiative Reporter, Brockville Recorder and Times