WATERSHED CONDITIONS STATEMENT: Flood Outlook – St. Lawrence River

13-Mar-2020 27-Mar-2020

March 13th, 2020

Weather Forecast:
Environment Canada is forecasting a freeze-thaw cycle for the next 7 days as high temperatures between 2 to 8°C are expected until Thursday, March 19th. Forecasted rainfall amounts of 15 to 25 mm are expected to end today and no significant precipitation is in the forecast for the next week.

There will be strong winds of 50 to 80 km/h today and Saturday, March 14th, and 30 to 50 km/h winds on Sunday, March 15th.

Environmental Conditions:
According to the International Lake Ontario – St. Lawrence River Board, Lake Ontario’s water levels are above average for this time of year and will remain stable or rise slightly this coming week.

Continuing high inflows from Lake Erie into Lake Ontario means that Lake Ontario will continue its seasonal rise headed into the spring and may remain near seasonal highs for the next several weeks. Outflows from Lake Ontario continue to be maximized to the extent possible.

Lake Ontario water levels rose 4 cm this week; 51 cm above average; and 14 cm below record-high set in 1952.

Recent precipitation along with its associated snowmelt may increase water levels and cause flooding along the shoreline or in low lying areas.

Residents are also advised that strong winds may cause large waves, further aggravating water levels which may affect structures close to shore.


Residents are advised to exercise caution when near rivers as the forecasted weather may rapidly increase river flows and cause slippery river banks. Parents are encouraged to explain these dangers to their children.

Residents in flood prone or low-lying areas, historically susceptible to flooding, should 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 backup generator and 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 statement is in effect until Friday March 20th, 2020.

SNC monitors 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: Geoff Owens, SNC Regulations Officer,

MEDIA CONTACT: Taylor Campbell, SNC Communications Specialist,

Forwarded to:  All Flood Forecasting and Warning Directory