News Releases

In an easy-to-read background paper on High Water in 2019, the International Lake Ontario-St. Lawrence River Board responds to the call for more accessible information.

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.

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. 

While Lake Ontario remains above long-term average, regulated outflows will remain as high as feasible based on river conditions. As a result, residents around Lake St. Lawrence are being warned to expect both extreme high and low water levels this winter, as the Board implements a winter deviation…

The International Lake Ontario – St. Lawrence River Board (Board) announced today that, in directing Lake Ontario outflows, it has been given the ability to continue deviating from the flow specified by Plan 2014.

To provide the highest attainable relief to all interests, both upstream and downstream of the Moses-Saunders Dam, outflows remain at record-high rates for this time of year, eclipsing the outflows released at this same time in any other years dating back to 1900.

Due to the declining Lake Ontario level combined with extraordinarily high outflows still being released through Moses-Saunders Dam, the forebay upstream of the dam has seen a significant sustained drop in water levels, making it extremely challenging to haul-out boats that would normally be…
Lake Ontario levels reached 75.50 m (247.7 ft) and the record outflows of 10,400 m3/s (367,270 cubic feet per second) were reduced to 10,110 m3/s (357,000 cubic feet per second) at 12:01AM on August 21, 2019. 

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.