News Releases

The risk of flooding on Lake Ontario and the upper St. Lawrence River has declined from moderate in December 2020 to low. In December, the risk analysis indicated a 28% chance of water levels exceeding a threshold at which damages occur in many shoreline communities. The risk is now down to 8%.…

The International Lake Ontario - St. Lawrence Board is optimistic that weather conditions the rest of this winter and spring won’t cause a damaging rise in Lake Ontario levels this year.

The International Joint Commission (IJC) has approved the Board’s request for authority to deviate from Plan 2014, and as conditions permit, outflows from the Moses-Saunders dam on the St. Lawrence River can be increased to exceed Plan 2014 flows.

The Board will temporarily decrease outflows over the second weekend of October to raise Lake St. Lawrence levels significantly and provide a brief, final opportunity for residents of Lake St. Lawrence to remove their boats and other equipment prior to winter.

A public Great Lakes water levels webinar hosted by the International Joint Commission's Lake Superior Board of Control, Lake Ontario-St. Lawrence River Board and Niagara Board of Control was held July 17.

With summer nearing an end, the Board will adjust its outflow strategy and allow Lake St. Lawrence levels to decline to the normal navigation season minimum following the September long weekend. This decision will allow for slightly more water to be released from Lake Ontario during the fall.

Lake Ontario levels peaked early this year at 75.40 m (247.38 ft.) on 5 May, 10 cm (4 inches) below the general flood stage and over a half meter (20 inches) lower than the peak in 2019. Lake levels are expected to continue their seasonal decline through summer, and have fallen 6 cm (2 in.) from…
Thanks to favorable weather and water supply conditions, in conjunction with recent actions taken by the International Lake Ontario-St. Lawrence River Board to increase Lake Ontario outflows, the board no longer needs to limit outflows to alleviate flooding risks downstream.
Water levels throughout the Lake Ontario – St. Lawrence River system in 2020 are expected to peak well below the record-highs of 2017 and 2019, according to the latest projections from the International Lake Ontario-St. Lawrence River Board.
Water levels remain high across the Great Lakes basin. The four upper Great Lakes are near- or above record-high levels, while Lake Ontario is still well above average, but also well below record levels. Lake Ontario is now likely to remain below record-highs through the spring.