Flood Outlook Statement: Saint Lawrence River - Update #1

24-Apr-2019 24-Apr-2019

This statement is an update to the Flood Outlook statement issued April 18th, 2019

Weather Forecast:
Environment and Climate Change Canada is forecasting rainfall of 15 to 20 mm this Friday, and an additional 5 to 10 mm Saturday through Sunday, April 28.

Environmental Conditions:
According to the International Lake Ontario – St. Lawrence River Board (ILOSRB) water levels upstream of the Iroquois area are rising as Lake Ontario’s level rose last weekend.

While Lake Ontario’s current water level is above average, it is still within the historical range of observed levels at this time of year and currently well-bellow the extreme highs of 2017.

Water levels between the Iroquois Dam and Moses-Saunders Dam has been rapidly increasing due to reduced outflows from Moses-Saunders Dam to limit flooding near Montreal.

Gates at Iroquois have been lowered to supress water levels and keep them below flood values in the area.


According to the ILOSRB, Lake Ontario is expected to further increase this week as a result of precipitation forecast for today combined with reduced outflows and high inflows from Lake Erie.

As a result of the increased outflows of Lake Ontario, Saint Lawrence River levels upstream of Iroquois throughout Edwardsburg/Cardinal and Augusta Township


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, such as:

  • Ensuring sump pump is clear, in good working condition and has a backwater valve on it.
  • Portable generator and backup pump.
  • Ensuring downspouts are clear and the outlet is at least 3 m from the dwelling.
  • Removing or securing items that might float away as flows increase.
  • Removing valuable items from basements or lower floors that could be subject
    to flooding
  • Keep emergency phone numbers handy.
  • Familiarize yourself with your municipality’s emergency preparedness plan.


This Flood Outlook statement is in effect until Wednesday, May 1, 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, posted on our Facebook (/SouthNationConservation) or Twitter (@SouthNationCA).

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

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

Forwarded to: All Flood Forecasting and Warning Directory