Flood Warning Update – Lake Ontario & St. Lawrence River (High) Static Water Level

Published on: 2019/07/24 - in Releases

RELEASE — The Cataraqui Region Conservation Authority (CRCA) has updated its Flood Warning Statement today for Lake Ontario and the St. Lawrence River.

The International Lake Ontario – St. Lawrence River Board (ILOSLRB) is reporting a lake-wide water level of 75.80 m, as of July 21, about 12 cm below this year’s peak of 75.92 m, last recorded June 15. The level, which had begun a slow decline, recently plateaued as a result of heavy rainfall on July 17, the remnants of Hurricane Barry. Lake Ontario outflows remain at 10,400 m3/s since June 13, equivalent to the record-high outflows released for several weeks during the summer of 2017.

The ILOSLRB, who manage Lake Ontario outflows, states that, “According to this week’s forecast, levels should resume their slow decline during this coming week.”

The current water levels measured at Kingston and Brockville of 75.71 metres and 75.30 metres respectively, are still very high. Flooding and erosion damage from high waves remain a concern.

An Updated Provincial Flood Watch Statement, issued by the Surface Water Monitoring Centre (SWMC) of the Ontario Ministry of Natural Resources and Forestry on July 5, remains in effect.

What this means in simple terms is that unusually high water levels remain, resulting in localized flooding and erosion impacts in flood prone and low-lying areas, especially during periods of strong winds and high waves. Depending on rainfall amounts, water levels are expected to resume a slow decline this week, but related flooding and erosion concerns are likely to persist for weeks to come.

The CRCA is urging residents to pay close attention to forecasts for approaching storms with high winds from the southeast, south or southwest.

If you witness flooding and require assistance your first point of contact is the local municipality. CRCA does not provide sandbags. However, information about where to purchase sandbags is provided at www.crca.ca/flood.

Property owners are also reminded to turn off electricity to buildings or structures in flood prone or low-lying areas and to move gasoline and other chemicals to higher ground. Any work along shorelines (e.g. placement of fill, armour stone, etc.) will require a permit from the CRCA. Call our office or visit our website www.crca.ca for further information.

CRCA appreciates feedback from the public and municipal staff detailing flooding and erosion impacts. Please report observations on the online form at www.crca.ca/flood.

Staff will continue to monitor ILOSLRB forecasts and SWMC Provincial Statements, and update CRCA messaging as needed. This Flood Warning Statement will remain in effect until (or updated before) 11:59 pm August 21, 2019.

For further information on water levels, wind and wave forecasts, and Provincial flood messages visit www.crca.ca/flood.


See below for watershed conditions terminology:

Normal: No flood conditions exist

Flood Watch: Flooding is possible in specific watercourse or municipalities. Municipalities, emergency services and individual landowners in flood-prone areas should prepare.

Flood Warning: Flooding is imminent or already occurring in specific watercourses or municipalities. Municipalities and individuals should take action to deal with flood conditions. This may include road closures and evacuations.


Release: Cataraqui Region Conservation Authority
Photo (Lake Ontario): Ad Meskens (cc)