Highlights:

• Recent rain and snowmelt have caused the Thames River to rise and it is now peaking in the London area.
• Peak river levels will move downstream over the weekend arriving in the Chatham area late Sunday or Monday.
• Flooding expected in the low-lying river flats adjacent to the river from Delaware down to Chatham.
• Various rain forecasts are calling for 10 to 30 mm of rain in total overnight tonight and Saturday.
• Areas of ponding, standing water and localized flooding could be seen around the watershed.
• Smaller local watercourses will rise and some could spill their banks.

Message:

Recent warm temperatures, rains, and the associated melting snow have caused water levels on the Thames River to rise. It appears that water levels on the Thames River are peaking now in the London area. The peak will move downstream over the weekend and is expected to arrive in the Chatham area late Sunday or Monday. As the peak moves downstream, it will flood the low-lying river flats adjacent to the river from Delaware down to Chatham. Flooding of the upper table lands is not expected.

There is the potential for a significant rainfall event beginning overnight tonight and lasting throughout the day on Saturday. Various forecasts suggest total rainfall amounts in the 10 to 30 mm range, with most suggesting around 20 mm. Given the saturated condition of the watershed, the ground can’t absorb much more rain. This amount of rain could lead to ponding, areas of standing water and localized flooding.

This rain will also cause our smaller local watercourses to rise and some could spill their banks. Due to high river levels, these watercourses tributary to the Thames River could have a difficult time draining the water away. Even higher than usual water levels should be expected in downstream areas near the river. If the higher rainfall amounts appear, the LTVCA may need to operate the McGregor Creek Diversion Channel at Chatham and is prepared to do so.

At this time, it is not expected that the LTVCA will need to operate the 6th St. Dam in Chatham. However, the predicted rain would be running off into local watercourses and the Thames River as the river peak makes its way downstream. This will add flow to the river, and the water level of the river, as the peak moves downstream. This will lead to higher water levels downstream than is typically associated with the current peak levels in London. The LTVCA will be closely monitoring how much rain falls, its impacts, and any required infrastructure operations.

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

As water levels rise, it is not safe to take shelter along riverbanks or in low-lying areas that are prone to flooding.

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

This message will be in effect until March 29th, 2023.

Message Contact: Jason Wintermute ([email protected])