Find us on Facebook

Water levels dropping on Lake Ontario, but remain near record high

Posted 9 August 2019 at 12:10 pm

Photo by Tom Rivers: A boat is on Lake Ontario during sunset on Sunday evening near Barker.

Press Release, International Joint Commission

Water levels on Lake Ontario have begun to decline more rapidly in recent days due to a combination of continued record-high outflows, declining inflows from Lake Erie and generally drier weather across the basin.

Lake Ontario’s level remains at record-highs for this time of year, but it has declined about 29 cm (11.4 in) since June 13, when outflows were first increased to 10,400 cm3/s (367,270 cubic feet per second).

This record-high outflow has now been sustained for a record duration, with Aug. 7 marking the 56th consecutive day of flows at 10,400 m3/s (367,270 cfs), more than the 55 days that the same record-outflow was sustained during the summer of 2017, when it lasted from June 14 to Aug. 7.

However, Lake Erie’s level also remains at record-highs and its outflow, most of which passes through the Niagara River, continues to add water to Lake Ontario at a record-rate. Nonetheless, Lake Erie has also been declining recently, and this has allowed Lake Ontario’s rate of decline to increase slightly over the last several days. Lake Ontario has been dropping at a rate of about 1 cm (0.4 in) per day since August 2nd, and after some scattered rainfall the past day or so, drier weather is expected to return and continue through the end of the week allowing lake levels to continue to decline.

The Board is acutely aware and concerned for the welfare of the many affected shoreline property and business owners, as well as the shoreline environmental damage and other impacts of the continuing high water levels.

The Boards’ current regulation strategy includes deviations from the prescribed flows of Plan 2014 with the specific intention of maximizing the rate of relief that lower water levels will provide to those affected.

Return to top