Highlights:

• Water levels on smaller watercourses should begin falling this evening or overnight.
• The Thames River will rise and flood the river flats from Delaware down to Chatham.
• Ice on the Thames River has begun to break up and move downstream. Sudden surges in water levels can occur when ice jams form.

Message:

Over the last few days, the Thames River watershed has seen temperatures well above freezing. Together with these warm temperatures, the watershed also received around 15 mm of rain, mostly overnight last night. The warm temperatures and rain have melted almost all the snow out of the lower Thames River watershed and has also started to melt the much deeper snowpack in the upper Thames River watershed. Forecasts suggest that the region could see another few millimetres of rain this evening and overnight before temperatures drop below freezing. Any rain would then turn into snow.

As a result of the rain and melt, water levels have risen on the region’s smaller watercourses that drain into the Thames River or directly into the lakes. Many of those watercourses are now peaking and could be expected to begin dropping this evening or overnight. Some watercourses may still be blocked with ice and snow and will take longer to drop back to normal water levels. The McGregor Creek Diversion Channel in Chatham is currently diverting McGregor Creek flows around the city.

Water levels on the Thames River are also rising due to the rain and snowmelt. Water levels are expected to peak in the City of London tomorrow. The amount of water leaving the upper Thames watershed will cause flooding of the low-lying river flats adjacent to the river from Delaware down to Chatham. Based on current forecasts, the LTVCA does not expect to have to operate the 6th St. Dam, and flooding in the city of Chatham is expected to be limited to the sidewalk along the river in the downtown, Simcoe Lane, and other low-lying areas adjacent to the river that tend to flood frequently.

The ice on the lower Thames River has begun to break and begin moving downstream. As of late this afternoon, the ice upstream of Thamesville had largely broken up and moved down river into the Kent Bridge area. The river ice was still largely intact between Louisville and Communication Road. Through the city of Chatham, the ice has also broken up and started to move downstream. However, as of this morning, the river was largely free of ice from Keil Dr down to Crow Road, with the river ice intact down to the mouth at Lighthouse Cove. No major ice jams have been observed on the river. However, as the ice moves downstream, even minor ice jams can cause sudden surges in water levels and raise water levels in the area. Ice conditions and potential jam locations should be monitored through the weekend. If ice jams occur, the LTVCA may need to operate the 6th St. Dam, and water levels in the city could rise higher than mentioned above. The cooler temperatures predicted over the next few days may solidify and ice jams that occur.

People should take extra caution and avoid the river, ditches, and streams. The combination of slippery banks, broken or unstable ice and fast-moving cold water can be dangerous. Standing water can also present its own unseen hazards. Children and pets and livestock should be kept away from the water.

Officials will continue to monitor the situation and update this advisory if necessary.

This message will be in effect until March 11, 2025.

Message Contact: Jason Wintermute ([email protected])