Kingston – The Cataraqui Region Conservation Authority (CRCA) has issued a Flood Outlook Statement today for Lake Ontario and the St. Lawrence River shoreline.
The water levels on Lake Ontario and the St. Lawrence River are currently well above average for this time of year. The Lake Ontario level at Kingston is as much as 55 cm higher than the average level for April, and 35 cm higher than the average level for June (June is typically the seasonal high). St. Lawrence River levels at Brockville are 50 cm above average April, and 30 cm above average June levels. Given that the peak water levels typically occur in June, it is expected that water levels will continue to rise over the next weeks.
The current high water levels are partly a result of high flows and flooding on the Ottawa River, and partly a result of extensive rainfall in the Lake Ontario drainage basin in early April that also caused flooding on inland lakes across eastern Ontario.
There are minimal water control structures on the Ottawa River system to help store water during flood events, and to minimize flooding at the confluence of the Ottawa and St. Lawrence Rivers and further downstream, the International Joint Commission (St. Lawrence River Board of Control) typically reduces outflow from Lake Ontario during events. This results in higher water levels on the St. Lawrence River and Lake Ontario.
See News Release from the St. Lawrence River Board of Control.
Shoreline residents should take care as these high water levels, combined with high winds and waves, could cause erosion and damage to their shoreline and shoreline infrastructure. In 1993 and 1998, when lake levels were similarly high, there was an increased occurrence of wave induced erosion.
There is the potential for erosion damage to shoreline areas, particularly if there are high winds. Within the Cataraqui Region, 40 km per hour winds (or more) from the southwest for more than a 24 hour period are the most critical. Areas west of Kingston and in the eastern end of the Bay of Quinte are most prone to damage by wind erosion. Under prolonged southwest winds, the water surface of Lake Ontario tilts, creating even higher water levels near Kingston.
Excessive boat wake can also cause shoreline erosion. Boaters should be careful about their boat wakes, especially with these high-water conditions.
Shoreline property owners and municipalities need to have a plan to minimize damage to life and property, and should ensure that any personal property along the shoreline (boats, docks, etc.) are fully secured. Property owners are also reminded that any work along the shoreline (e.g. placement of fill, armour stone, shorewalls, docks, etc.) requires a permit from the Cataraqui Region Conservation Authority, and should call the office or visit our website for more information.
High Lake Ontario levels typically last for weeks, or months, and it is possible that these higher than normal levels will last well in to the summer season.
Widespread flooding is NOT expected as a result of current conditions.
This Watershed Conditions Statement will remain in effect until Friday May 26, 2017.