SNC updates Flood Watch for St. Lawrence River

Provided by South Nation Conservation Authority
SNC updates Flood Watch for St. Lawrence River
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Weather Forecast:
Rainfall of 10 to 15 mm is forecasted for today, May 10, 2019.

Environmental Conditions:
Lake Ontario’s levels are increasing due to significant precipitation, reduced outflows, high inflows from Lake Erie, and spring runoff.


Water levels between the Iroquois Dam and Moses-Saunders Dam in Cornwall have been increasing due to reduced outflows at the Moses-Saunders Dam. Gates at Iroquois were lowered to supress water levels and keep them below flood values in the area.

The current water level elevation of the Saint Lawrence River at Brockville is 75.283 m. This is 0.217 m below what was observed in 2017 (75.5 m).

According to the International Lake Ontario – St. Lawrence River Board:           

Lake Ontario’s water levels are expected to further increase this week.

Lake Ontario’s increased outflows may increase Saint Lawrence River levels upstream of Iroquois throughout Edwardsburg/Cardinal and Augusta Township.

Residents are advised that wind may cause larger waves, further aggravating water levels which may affect structures close to shore.

Continued vigilance remains critically important; residents are advised to stay away from rivers as the forecasted weather may rapidly increase river flows and banks might be unstable and slippery. Parents are encouraged to explain these dangers to their children.

Residents in flood prone or low-lying areas historically susceptible to flooding are encouraged to closely follow evolving conditions and should also take the necessary precautions to protect their property.

This Flood Watch statement is in effect until Thursday, May 16, 2019.

SNC monitors the water levels and weather forecasts as part of the Flood Forecasting and Warning Program. Updates are provided as conditions change.

The International Lake Ontario – St. Lawrence River Board continues to monitor conditions on an ongoing basis. Information on hydrologic conditions, water levels and outflows, including graphics and photos, are available on the Board’s website at

Please visit for more information. To provide feedback with respect to changes in water related conditions please email, post on our Facebook (/SouthNationConservation) or Twitter (@SouthNationCA).

FOR MORE INFORMATION: Omar Kana’n, SNC Water Resources Analyst,

FOR MEDIA INQUIRIES: John Mesman, Team Lead of Communications,

Forwarded to: 
All Flood Forecasting and Warning Directory

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