50% Chance Water Levels Will Match or Exceed Highs of 2017

Published on: 2019/05/17 - in Releases

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

The Weekly Water Level Forecast from the International Lake Ontario – St. Lawrence River Board (ILOSLRB), issued May 16, suggests there is “a 50% chance that within two weeks levels will reach or exceed the highs of 2017”. Under “average” conditions, a peak of approximately 75.9 m is expected to occur in early June. Higher water levels are possible under wetter conditions.

An Updated Provincial Flood Watch Statement, issued by the Surface Water Monitoring Centre (SWMC) of the Ontario Ministry of Natural Resources and Forestry on May 10, remains in effect.

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The current water levels measured at Kingston and Brockville are 75.65 metres and 75.45 metres respectively, which are both 0.35 metres below the 100-year flood levels of 76.0 meters and 75.8 metres in those areas.

In 2017 water levels exceeded 75.8 m and 75.5 m, locally, on Lake Ontario and St. Lawrence River, respectively. Impacts in 2017 included submerged and/or damaged docks, boathouses and boat ramps, inundated/eroded shorelines, submerged gas docks (at marinas), flooding around homes and cottages in a few locations, and closed or constrained municipal roads. These impacts are already occurring or expected to occur again this year.

What this means in simple terms is that residents should expect the peak water levels experienced in 2017 to occur again this year by the end of May and into June, resulting in similar localized flooding and erosion impacts in flood prone and low-lying areas.

Municipalities have been advised and are assessing the situation to determine appropriate response. 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 crca.ca/flood.

Flooding and erosion damage from high waves are possible during periods of strong winds. The CRCA is urging residents to pay close attention to forecasts for approaching storms with high winds from the southeast, south or southwest, and note that the above mentioned 100-year flood elevations do not include wave uprush (increased water levels resulting from high waves).

Over the next few days winds from the south and west (e.g. SW 37 km/h, gusting to 56 on Monday, May 20) will continue to have a noticeable impact on water levels in the area.

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 crca.ca/flood, where you can also find further information on water levels, wind and wave forecasts, and Provincial flood messages.

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) June 12, 2019.

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 source: Cataraqui Region Conservation Authority
Photo – St Lawrence Seaway: Michel Rathwell (cc)