Flood message issued
20-30 millimetres (mm) of rainfall expected this weekend. Higher amounts possible in thunderstorms.
High water levels are expected and residents are reminded to stay away from waterways.
A ’Colorado Low‘ weather system will be moving into the area on Saturday afternoon bringing with it 20 to 30 millimetres (mm) of rainfall starting late Saturday, March 15, 2025 into Sunday. There is also the possibility of isolated thunderstorms that could result in precipitation totals exceeding 30 mm in localized areas. This system will also bring a quick increase in temperatures, forecasted to be up to 20° Celsius.
The snow survey, conducted by Ausable Bayfield Conservation Authority (ABCA) staff today (March 14, 2025), shows that following the daytime highs, above freezing this week, only trace amounts of snow remain in most of the watershed. Snowmelt has saturated most of the ground. Any rain received this weekend will fall on wet ground and result in a quick runoff and response in the streams and watercourses. Streamflow forecasts show most rivers are expected to peak through the day on Sunday, with the larger rivers peaking into Monday. Major flooding is not anticipated but, should we receive the higher amounts of precipitation, river levels could approach those of last week, resulting in flooding of low-lying flood plain areas, which may result in some road closures.
There is no longer any risk of ice jams in the main rivers.
Residents are reminded to use caution near all watercourses as waters will be fast-moving and higher than normal, especially since this is the last weekend of the March Break for schools. Slippery and unstable streambanks and extremely cold water temperatures will create additional hazards. Any ice on local waterbodies should be considered extremely unsafe.
As before, municipal staff should continue to monitor local drainage problem areas where water is ponding or frozen especially where they may have covered catch basins. The Parkhill Dam is still holding an elevated amount of water from last week’s rain and melt, which has significantly reduced flooding downstream. ABCA staff continue to monitor and are prepared to operate the dam if the higher end of the forecasted precipitation materializes.
This message will remain in effect until 9:00 a.m. on Tuesday, March 18, 2025, unless otherwise updated. The Ausable Bayfield Conservation Authority (ABCA) will continue to monitor watershed conditions and will provide an update if required.
Details are available on our flood messages web page.