The St. Clair Region Conservation Authority has upgraded its flood watch to a flood warning for the Sydenham River watershed.
The authority said water levels are quickly rising following heavy rain overnight, and there's some flooding in low lying areas, on farmland and in parks.
Director of Water Resources Girish Sankar said up to 30 millimetres of rain, over an inch, has fallen over the last 24 hours, and the spring season, so far, has seen near-record rainfall.
"It's been almost three weeks we've been receiving a lot of rain," said Sankar. 'The rainfall amounts have been anywhere between 40 to 60 millimetres in each of those events. A couple of weeks before we had 40 to 60 millimetres, another 40 to 60 last week and another 40 to 60 this week, so it's been a lot of rain."
Sankar said several roads in St. Clair Township are closed due to flooding.
They include Pretty Road north of McCallum Line, Waterworks Road between Courtright Line and Moore Line and Stanley Line east of Kimball Road.
Minor flooding in Wallaceburg is also expected.
"It will be early next week when things would be going back to normal," said Sankar. "The next 48-hour forecast is calling for another 15 to 20 millimetres of rain and the winds are also coming from the south for a short period of time, which sort of holds back the water a little longer."
Residents are urged to stay clear of slippery banks and cold, fast-moving water along swollen streams and rivers.