The St. Clair Region Conservation Authority says high water levels across the watershed could persist for several more days as additional rainfall is expected this week.
In an updated flood watch issued Monday, the authority said between 20 and 50 millimetres of rain has fallen across the region over the past four days, leaving rivers and streams elevated.
Water levels are beginning to fall but remain high, with most smaller watercourses still over their banks and flooding low-lying areas that typically flood during the spring.
Another 15 to 25 millimetres of rain is forecast between Tuesday and Wednesday. Officials say some of the rainfall could come as thunderstorm activity, which may lead to higher totals in some areas.
“Water levels are starting to fall but are still high. Rainfall and snowmelt over the past week have saturated the ground. More rainfall will quickly produce runoff and reverse the downward trend in water levels, causing levels to rise, and prolonging the overall duration of this flood event.”
Rain combined with a prolonged period of unseasonably warm weather has also melted remaining snow, producing significant runoff and causing rivers and streams to rise.
The conservation authority said watercourses along the east and north branches of the Sydenham River peaked Sunday and are now trending downward, although levels across the region remain elevated.
Ice has been flushed out of the rivers, and officials say the risk of flooding caused by ice jams is not considered a concern at this time.
The authority is aware of a road closure in St. Clair Township on Stanley Line between Kimball Road and Waubuno Road.
Municipal staff are being advised to monitor local conditions closely, particularly in areas known to experience drainage issues.
Residents are also being urged to stay away from watercourses and flooded areas because of slippery banks, unsafe ice and fast-moving, cold water. Children and pets should be kept away from the water.
The conservation authority said it will continue monitoring watershed conditions and will issue further advisories to municipalities and media if flood concerns increase.
The flood watch will remain in effect until March 13 unless updated.
