The St. Clair Region Conservation Authority has issued a flood watch, following significant rainfall over the past two days.
The recent low pressure system dumped between 15 and 45 millimetres of rain across the region.
The authority said elevated water levels are continuing to rise slowly into floodplain areas in Brigden, Florence, Alvinston and Petrolia.
Flooding has forced the closure of Waterworks Road from Moore Line to Courtright Line and Fairweather Road between Oil Springs Line and Aberfeldy Line.
The authority said there's also the potential for flooding along Stanley Line between Kimball Road and Waubuno Road, as well as on Pretty Road north of McCallum Line.
Residents are reminded to avoid watercourses and flooded areas due to slippery banks and swift-moving water.