Lower Trent Conservation advises local municipalities and the public that a Flood Outlook Statement has been issued for Lake Ontario and Bay of Quinte shoreline from Grafton to Quinte West.
Residents along the shoreline should be aware of the potential for erosion and flooding.
This statement is an update to the previously issued Flood Outlook Statement on May 1, 2026.
A rise in Lake Ontario water levels over the spring has moved the lake to above normal levels for this time of year. Lake Ontario water levels increased to 75.30 metres above sea level by the end of April, an increase of 0.76 m since the start of March. This is in response to significant precipitation throughout the Lake Ontario basin, high inflows from Lake Erie and spring freshet flows from local inputs. Lake Ontario outflows have slowly been increasing to allow more water to exit the system to stabilize water levels on Lake Ontario. The International Lake Ontario-St. Lawrence River Board (Board) is closely monitoring conditions and adjusting Lake Ontario outflows frequently in accordance with Regulation Plan 2014.
Currently, the lake level at Cobourg is approximately 75.3 metres above sea level, which is 35 centimetres above the long-term average for May. Although Lake Ontario water levels are above average for this time of year, the observed water levels are currently well below the extreme highs of 2017 and 2019. It is forecast that the water levels will remain elevated throughout the spring and summer months and possibly into September, at which time water levels should continue to decrease towards more seasonal averages.
High onshore winds may result in greater short-term fluctuations of water levels, as well as increased flooding and erosion.
Water levels on the Great Lakes naturally vary, responding monthly, seasonally and annually to a variety of factors. Water levels are primarily influenced by natural factors, including precipitation, evaporation, winds, runoff from rivers or streams and inflow from upstream Great Lakes. The Moses-Saunders Dam, approved by the International Joint Commission in the 1950’s, also provides some control over water levels and flows.
Lake Ontario typically reaches its seasonal high-water level in May/June. Residents living along Lake Ontario and the Bay of Quinte should expect further increases in water levels for at least the next month.
Residents should ensure personal property (boats, docks, etc.) along the shoreline is secured. Property owners are also reminded that any work along the shoreline (e.g., place of fill, armour stone, etc.) will require a permit from Lower Trent Conservation and should call the office or visit the website for more information.
This Flood Outlook Statement will be in effect until (or updated before) Tuesday, June 30, 2026 at 4:00pm.
