Sarnia's sewer system was overwhelmed by the amount of rain that fell during Thursday's thunderstorms.
Environment Canada said a total of 45 millimetres of rain fell in Sarnia Thursday, of which 44 millimetres was recorded during the night-time storms.
A number of roads were closed due to significant flooding overnight, including Murphy Road and Finch Drive impacting homes in Sherwood Village, Cardiff Acres and Coronation Park.
Sarnia's Director of Engineering David Jackson said it was one of the worst rain storms the city has dealt with in the last few years.
"It was just a huge quantity of rain," said Jackson. "And, the fact that we had just had that other storm yesterday and so the ground was already saturated, so yeah just that amount of rain overwhelmed the sewer system. Interestingly, we got certainly vastly different amounts of rain in different parts of the city. This one did really affect mainly the southeast end of the city. Most of the flooding is in areas south of Highway 402, and largely kind of the southeast corners seems to be the worst hit."
Jackson said by about 9:30 a.m. Friday, the city had already heard from over 100 homeowners reporting flood damage.
"If they have had property damage, they need to work with their insurance company to address that," he said. "The flooding seems to be all sorts of different types, whether the sump pump couldn't keep up, could be the sewer backed up into the basement and some is water just seeping in through the walls."
He said the city did recently pass a basement flooding grant program.
"People can apply to install a backwater valve, which would help prevent sewers backing up into the basement when the sewer surcharges," said Jackson. "So there are some programs that they can reach out to the city to look at. In general we encourage people to reach out to the city to advise us of the flooding so that we can track that, and it helps us understand where we need to work on things in the system."
The thunderstorms and lightning are also blamed for a handful of brief power outages according to Bluewater power.
