A significant rainfall event is expected in southern Ontario as a Colorado Low moves into the region on Wednesday, April 2, 2025. The system is expected to bring 40 to 60 mm of rain within 24 hours, with the heaviest rainfall likely in the northern part of the Ausable Bayfield Conservation Authority (ABCA) watershed. Some areas may receive even higher amounts.
Rivers and streams in the region are already swollen after receiving 20 to 25 mm of rain over the weekend. With the ground still saturated, the additional rainfall could lead to rapid runoff and a quick rise in water levels. Flooding is expected, though the severity will depend on how much rain ultimately falls. If higher amounts occur, water levels could reach their highest in several years, leading to significant flooding and possible road closures. If rainfall totals remain on the lower end, flood levels will be similar to recent events.
Smaller rivers and creeks are expected to peak late Wednesday into early Thursday, while larger rivers will likely see peak levels on Thursday, April 3.
Residents are urged to use extreme caution near rivers and streams. The combination of slippery banks, fast-moving water, and cold temperatures creates dangerous conditions. Driving through flooded roads is highly discouraged, as hidden hazards such as washouts and debris may not be visible.
Municipal officials are advised to monitor low-lying areas, clear catch basins, and ensure stormwater systems are functioning properly.
This flood watch remains in effect until 9:00 a.m. on Monday, April 7, 2025, unless conditions change. The Ausable Bayfield Conservation Authority will continue to monitor the situation and provide updates as needed.
For more information, visit www.abca.ca.