Highlights:

• The entire lower Thames watershed has seen significant rainfall ranging up to 60 mm over the last 3 days.
• Between 25 and 30 mm of that fell since last evening when many smaller watercourses were already bank full.
• Many smaller watercourses have already responded to the heavy rains and have spilled their banks.
• Areas of ponding, standing water, and localized flooding seen throughout the watershed.
• Thames River expected to rise and flood the river flats from Delaware down the Chatham.

Message:

A series of weather systems has moved through the region over the last few days bringing rain and temperatures above freezing. Over the last three days, most of the lower Thames watershed has received between 40 and 60 mm of rain, with 20 to 30 mm falling since last evening. These rains and warmer temperatures have also melted the snowpack which has added to the amount of water running off the land into the region’s watercourses. Weather forecasts are calling for small amounts of rain, maybe up to 5 mm each day, for the next few days.

The rain since last evening came when many of the region’s smaller watercourses were already near bank full conditions. There were already areas of ponding, standing water, and localized flooding, which have since worsened. Throughout the day, watercourses should be expected to rise further and continue to flood adjacent low-lying areas. Ice and snow in the smaller watercourses have already led to blockages in some areas and could worsen the localized flooding. The McGregor Creek Diversion Channel at Chatham is currently in operation. Water levels should be expected to remain high through the weekend.

The Thames River is also rising in response to the rains. Already it has risen high enough to flood over the sidewalk along the river in downtown Chatham. The river should be expected to rise and flood the low-lying river flats from Delaware down to Chatham. Water levels should be expected to remain high into early next week. At this time, it is unclear if any further action will be required as the rain is still falling in the upper Thames watershed.

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. Any remaining ice on the river or smaller watercourses should be considered unstable and 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 January 31st, 2024.

Message Contact: Jason Wintermute ([email protected])