Flood Watch issued
Ausable Bayfield Conservation Authority (ABCA) issued a Flood Watch on Tuesday, April 1, 2025 at 3 p.m. in the afternoon:
40-60 millimetres (mm) of rain forecasted, with locally higher amounts possible.
A quick runoff with widespread flooding is possible.
A Colorado Low will move into southern Ontario tomorrow (Wednesday, April 2, 2025) pulling in a steady inflow of moisture. Rainfall forecasts for the Ausable Bayfield Conservation Authority (ABCA) area, over the next two days, show a potential of 40-60 millimetres (mm) of rain falling in less than 24 hours, beginning late tomorrow morning and lasting into early Thursday morning. The track of the heaviest rains is unknown but current forecasts predict higher rainfall in the north half of the watershed.
The ABCA watershed received between 20 and 25 mm of rain over the weekend and water levels in rivers and streams have not yet fully receded. With saturated ground, further rain this week will result in a quick runoff and rapid rise in river levels.
Based on the current forecast, and streamflow forecasting models, flooding is expected. The extent of flooding will depend on the actual rainfall totals. If the higher forecasted rain amounts materialize this could result in the highest water levels seen in several years and an expectation of significant overbank flooding and road closures. Lower end rainfall totals are likely to result in levels similar to recent events. Flood levels on the larger rivers are expected to peak on Thursday (April 3, 2025), smaller rivers and creeks are forecasted to see peak levels late Wednesday and into early Thursday.
Residents are reminded to use extreme caution near all watercourses. Slippery and unstable streambanks, and extremely cold and fast-flowing water will combine to create hazardous conditions. Driving or otherwise crossing flooded roads is never safe. Even if the flooding appears to be shallow, flood waters can obscure submerged washouts, debris and other hazards. In preparation for this event, municipal officials should consider monitoring low-lying areas, clearing catch basins, and ensuring that stormwater management infrastructure is in good working order.
This message will remain in effect until 9:00 a.m. on Monday, April 7, 2025, 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.
Details also available at abca.ca on the flood messages web page.