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Watershed Conditions Statement: Flood Watch – High Water Levels in Lake Ontario UPDATED

Watershed Conditions Statement:

Flood Watch – High Water Levels in Lake Ontario

The Hamilton Conservation Authority (HCA) is advising that the current Flood Watch – High Water Levels in Lake Ontario, issued on July 27, 2017, has been downgraded to a Watershed Conditions Statement (Flood Outlook - High Water Levels in Lake Ontario)

Although winds have diminished, HCA is advising that strong winds and associated wave action may re-occur in the future, resulting in increased risk of shoreline flooding and erosion.  Strong winds occurring from the north or east would pose the primary concern for wave-related flooding and erosion potential.

Lake Ontario water levels continue to be significantly above normal.  However, water levels have been slowly but steadily declining recently, and in general water levels are expected to continue to gradually decline towards normal over the next several months.

HCA wishes to remind residents to continue to exercise caution near lakefront areas at this time, as high water levels and/or wave action may pose significant hazards.

 A close watch on shoreline and meteorological conditions is recommended. HCA continues to monitor Lake Ontario water level and wind conditions closely and will issue additional messages or further updates as required.

The Lake Ontario mean daily water level is currently 75.59 m IGLD85, which is 10 cm below the highest water level recorded for this time of year (set in 1947).  By comparison, the HCA shoreline flooding hazard level, used for planning and development review, is 78.5 m (which includes 2.5 m of wave uprush).

Additional information regarding current and forecasted Great Lakes water levels can be found at:

Forecasted, current, and recent Great Lakes Water Levels from US Army Corps of Engineers:

For further information or questions regarding this Flood Watch - High Water Levels in Lake Ontario message, please contact:
Jonathan Bastien, Water Resources Engineering
Phone: 905-525-2181 ext 138
Fax: 905-648-4622

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