The St. Clair Region Conservation Authority has issued a flood watch for the Sydenham River watershed as rainfall and warming temperatures are expected to raise water levels over the weekend.
Environment and Climate Change Canada and the Ministry of Natural Resources Surface Water Monitoring Centre are forecasting 10 to 20 millimetres of rainfall Friday night into Saturday, with the possibility of thunderstorms that could add another five to 20 millimetres.
The conservation authority says between 12 and 27 millimetres of rain has already fallen across the watershed over the past 48 hours, causing some watercourses to top their banks and begin flooding nearby low-lying areas.
Officials expect water levels to continue rising quickly through the weekend and remain elevated into next week, particularly if the higher end of the rainfall forecast occurs.
While much of the snowpack has melted, some snow remains in roadside ditches that could release additional water as temperatures climb to around 15 C on Saturday.
The conservation authority also noted that some ice remains in rivers in the lower portions of the watershed, which could increase the risk of flooding if ice jams occur.
Municipal staff are being asked to monitor local conditions closely, particularly in areas known to have drainage problems. Rural areas with drifting snow may have ditches and smaller watercourses partially blocked, which could increase flooding potential during runoff events.
Residents are reminded to avoid watercourses and flooded areas due to slippery banks, unsafe ice cover and cold, fast-moving water. Children and pets should also be kept away from waterways.
The conservation authority says it will continue monitoring conditions and will issue further advisories to municipalities and the media if flooding concerns develop.
The flood watch is in effect until noon Monday, March 9, unless updated earlier.
