A flood warning has been issued across the St. Clair Region watershed as rising water levels increase the risk of flooded roads, according to a Conservation Authority update issued Monday, Dec. 29, 2025.
St. Clair Region Conservation Authority officials say the warning follows a weekend of mixed precipitation that saw approximately 10 millimetres of freezing rain fall on Saturday, followed by above-freezing temperatures and between 15 and 30 millimetres of rain on Sunday. Water levels responded quickly, with flooding already occurring within natural floodplains and low-lying areas along the Sydenham River.
The Conservation Authority reports that water levels on Bear Creek near Brigden and Black Creek near Bickford Line are showing early indications of cresting. However, levels across both the north and east branches of the Sydenham River continue to rise, increasing the potential for road flooding, particularly in the areas of Strathroy, Petrolia, and the townships of St. Clair and Enniskillen.
Municipal emergency response staff and road superintendents are being urged to closely monitor local conditions and to relay information about flooded roads and any closures to Conservation Authority staff.
Forecast below-freezing overnight and daytime temperatures for the remainder of the week are expected to help keep snow and ice currently stored on land from entering the watershed system. At the same time, the lack of ice cover on local watercourses means that an additional five to 15 centimetres of snow expected from Tuesday through Wednesday could slow the rate at which water levels recede.
Residents are being reminded to avoid watercourses and flooded areas due to hazardous conditions, including slippery banks, unsafe ice and swift-moving water. Children and pets should be kept well away from the water.
The Conservation Authority says it will continue to monitor watershed conditions and will issue advisories to municipalities and media should further flood issues arise. The flood warning remains in effect until 12 p.m. on Wednesday, Dec. 31, 2025, unless otherwise updated.
