The St. Clair Region Conservation Authority issued a watershed conditions statement and flood outlook on Wednesday, September 24, 2025.
“Possible intense thunderstorms may cause flash flooding and water pooling on roads,” SCRCA officials stated.
“Possible thunderstorm activity this afternoon and evening has the potential of producing heavy rainfall in short periods of time. Environment Canada is advising that local rainfall totals produced by these thunderstorms could be up to 100 mm.”
SCRCA officials added: “Forecasts show that the most severe rainfall should stay south of the watershed, concentrated in the Chatham area. However, due to the sporadic and unpredictable nature of these storms, it is possible that Wallaceburg, Dresden, and Glencoe areas could be impacted should the storms track further to the north.”
High amounts of rainfall in a short period of time can lead to increased runoff and flash flooding, particularly in urban areas.
Local rainfall amounts could be higher due to the isolated nature of thunderstorms, SCRCA officials added.
“Water levels and flows are anticipated to increase and may elevate into natural floodplain areas should the watershed receive the upper end of the rainfall amounts,” officials say.
“Low-lying areas and roads prone to flooding may become impacted, and ponding may occur in saturated and/or slow-to-drain soils. Individuals are reminded to avoid watercourses and flooded areas due to dangerous conditions, slippery banks, and swift moving water. Children and pets should be kept away from the water.”
The Conservation Authority continues to monitor watershed conditions and will issue advisories to municipalities and media should flood issues arise.
Municipal emergency response staff and road superintendents should monitor local conditions closely.
This message will remain in effect until 12 p.m. on September 26, 2025, unless otherwise updated.
