Following the closure of the Seaway, and some partial and temporary ice formation in early January, mild temperatures across the Lake Ontario basin have allowed the International Lake Ontario - St.
Lake Superior and Lake Michigan-Huron remain near record-highs for this time of year, and although they are expected to continue their seasonal declines in January, levels are expected to remain high over the next several months and may again exceed record-highs if wet conditions continue in 2020.
Outflows will be increased substantially in the coming days as efforts to remove water from Lake Ontario continue.
Cold weather has caused ice formation to start at critical areas on the St. Lawrence River, requiring Lake Ontario outflows to be temporarily reduced in order to reduce the risk of ice jams.
Summary for Week Ending 11 December 2019
The average Lake Ontario outflow is expected to be 8,820 m³/s for the coming week. This flow rate is 200 m³/s above the normal safe navigation flow limit that applies at the current Lake Ontario elevation as defined by the regulation plan.