The Indian-McGregor Creek Diversion Channel looking south. February 24, 2016. (Photo by Simon Crouch)

Heavy Rainfall In Forecast Prompts Flood Watch

The Lower Thames Valley Conservation Authority (LTVCA) has issued a flood watch for Chatham-Kent and the London area as forecasts predict a rainy next few days.

The conservation authority says weather forecasts are predicting a system to develop over Southwestern Ontario that will drop large amounts of rain on Sunday through Wednesday. The region is expected to get around 20 to 30mm of rain tomorrow, 15 to 30mm on Tuesday, and 5 to 10mm on Wednesday. There is also the possibility of thunderstorms.

Temperatures will remain well above freezing during this period and are expected to range from 8c to 15c. The LTVCA says temperatures will not drop back below freezing until Wednesday night.

According to the conservation authority, there is approximately 40mm of water stored in the Upper Thames watershed snow. It is reported that the combination of prolonged heavy rain and melting snow could lead to flooding.

The heavy rain could also lead to localized flooding in areas with poor drainage. Water levels on the smaller local watercourses in the Lower Thames will begin to rise on Sunday and stay high through Thursday. The snow and ice could result in blockages and cause water to back up. The LTVCA will be operating the Indian-McGregor Creek Diversion Channel to protect the south end of Chatham from flooding.

The LTVCA says the Thames River will also rise and could reach levels that haven’t been seen in a decade. Peak water levels in London are expected Tuesday and Wednesday. This water will work its way downstream over the next few days, reaching Thamesville and Chatham on Thursday and Friday. Through Middlesex and Elgin Counties there could be flooding issues around bridge crossings and water will back up local watercourses.

Flooding is not currently expected for the community of Thamesville, but there is the potential if conditions worsen. It is reported that basement flooding is expected for businesses backing onto the Thames River along King St. in Chatham.

It is also very likely that there will be flooding on some of the low roads near the Thames. Water levels in the downstream areas can be expected to remain high all through next weekend. The LTVCA will be operating the 6th St. Backwater Dam and Pumping Station in downtown Chatham to protect the low lying portions of the city upstream on McGregor Creek.

Last week, ice thickness measurements were taken on the Thames River. The conservation authority says on average, there was 18 cm of ice thickness with about 8cm of that being poor quality white ice. Ice cover on the Thames River will melt, break up and move downstream during the warming weather.

Residents with properties that back onto watercourses should secure their belongings and remove any items that could be damaged and become loose by flooding. Residents should also ensure that catch basins and other drainage works are free of debris and can function properly.

People should take extra caution and avoid the river, ditches, and streams. The combination of slippery banks, broken up or degraded ice, and fast moving cold water can be dangerous. Children, pets, and livestock should also 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 Wednesday.