Flood watch issued
Date of issue: Sunday, December 28, 2025 at 2 p.m.
Heavy rainfall with totals of 40-50 millimetres (mm), higher amounts in thunderstorms.
A quick runoff with widespread flooding is possible.
Watershed residents are reminded to stay away from waterways.
A large, low-pressure system continues to move across Southern Ontario, impacting the Ausable Bayfield Conservation Authority (ABCA) watershed area with rain beginning this morning (Sunday, December 28, 2025).
Updated forecasts for the ABCA watershed area could see temperatures reaching up to 10 degrees Celsius overnight tonight, with rainfall totals in the range of 40-50 mm, and higher amounts possible in thunderstorms.
It is expected that most of the remaining snowpack (30-50 mm of water equivalent) will melt in this event. Combined with heavy rains on saturated ground conditions, a very rapid runoff is expected.
Based on the current forecast and streamflow forecasting models, water levels in rivers will exceed bankfull conditions, and extend well into the traditional low-lying undeveloped flood plain areas.
Riverine flooding is likely to affect local roads that are prone to periodic flooding.
Water levels are expected to peak through the day on Monday, and overnight into Tuesday, and will remain high on the larger rivers through New Year’s Day. With very little river ice remaining, ice jams are not expected.
Where snowbanks remain, municipal staff should monitor local drainage problem areas where snow conditions may have covered catch basins or culverts, causing overland drainage issues.
With the ongoing holiday break, special consideration should be given towards water safety during gatherings and outdoor recreational activities. Residents are reminded that all ice should be considered unsafe and to use caution near all watercourses. Slippery, unstable streambanks — often hidden by drifted snow — and extremely cold water temperatures, create additional hazards.
This message will remain in effect until 12:00 p.m. noon on Friday, January 2, 2026, unless local conditions warrant further updates. The Ausable Bayfield Conservation Authority will continue to monitor forecasts and watershed conditions through the week and will provide updates as required.