March 6, 2026
Streams and Rivers Hazardous as Spring Freshet Arrives
The Upper Thames River Conservation Authority (UTRCA) expects most of the remaining snow in the Upper Thames River watershed to melt this weekend, due to the warm temperatures, rain already received, and rain in the forecast.
Local streams and rivers have been rising throughout the week, with temperatures above freezing most days and 5-20 mm of precipitation measured. Forecasts call for an additional 10-30 mm of rain today and tomorrow.
The UTRCA’s snow survey on March 2 estimated 70 mm of snow water equivalent in the northern portion of the watershed, and 18 mm in the south. Approximately 5-10 mm has been released into watercourses from the snow since the survey, with the remaining water still in the snowpack.
With today’s warm temperatures and tomorrow’s temperatures potentially reaching 18 degrees C, most of the remaining snow will melt and make its way down the rivers and streams over the weekend.
The UTRCA expects streams and rivers to reach their highest flows on Saturday evening in the upstream areas of the watershed (Mitchell, St. Marys, Stratford, Woodstock, Ingersoll, etc.). The Thames River through London is expected to peak in the early hours of Sunday. Water levels will stay high into next week.
The public is reminded to use extreme caution near all local waterways. Stream banks may be slippery and unstable, and the water is very cold and fast-moving. Any ice cover will be weakened and unstable. Ice on flood control reservoirs is especially hazardous due to fluctuating water levels.
Stay out of any flooded areas and do not drive through flooded roadways. Caregivers are reminded to keep children and pets away from watercourses. It is not safe to take shelter along riverbanks or in low lying areas that are prone to flooding.
While the UTRCA does not expect serious flooding, there is uncertainty in the weather forecasts and in the estimates of remaining water in the snowpack. If the higher forecasts and volumes materialize, most traditional floodplain areas in the watershed will be inundated.
The UTRCA is operating its flood control reservoirs at Fanshawe, Wildwood, and Pittock Conservation Areas to reduce downstream flooding. UTRCA officials will be monitoring the situation closely and will update this bulletin if the conditions change.
- See Thames River water levels and flows
- Types of flood bulletins
- Find out how the UTRCA manages floods
Contact: Eleanor Heagy, Communications and Marketing Coordinator