Sarnia council approved the development of an immediate action plan to respond to last week's flooding during an emergency meeting Friday morning.
General Manager of Engineering and Operations David Jackson said while most flooding was from the sanitary sewer surcharging and coming up in basement floor drains, some was from sump pump failures or the inability to keep up with water seeping in through basement walls or entering window wells.
"The issue in Coronation Park is that storm water is getting into the sanitary sewer, which it shouldn't be," said Jackson. "A sanitary sewer can not handle that much storm water getting into it. All sanitary sewers would surcharge with that much water getting in. Over the last couple years, the city did smoke testing and we inspected our sewers to try to find reasons for storm water getting into the sanitary sewer on the city's side, unfortunately we did not find any significant source on the city side."
He said the only large source left to investigate is from private properties.
"That could be because people's home foundation drains are incorrectly tied into the sanitary sewer. It could mean sump pumps are incorrectly discharging into the sanitary sewer. Again, all sanitary sewers are not meant to handle storm water, because they'll become surcharged and cause flooding."
Jackson reported to council that the city has now received notice of around 300 properties being impacted by flooding.
"All sewer systems have this challenge of inflow and infiltration. So it can get in there through cross connections between the city sewer pipes, it can get in there if there's cracks in the pipes and there's a high water table. Again, those are the things we've tried to look for on our side and didn't find, and then it can get in there from the private side. Catch basins in a backyard that are connected, downspouts from a roof are connected into that and then it overwhelms it. So it is a capacity issue."
Councillor Bill Dennis said something has to be done and he took exception to Jackson's statement that all properties in the city are at risk of basement flooding.
"I was a realtor for 30 years and I know what areas of town have a reputation for water damage in basements, and flooding, and leaking, and believe me, there's no other area like this particular area," said Dennis.
Councillor Brian White described seeing the damage as "overwhelming."
"To walk down the street, to see the piles of rubble along the boulevards, to see how many disaster relief teams are out at any given point, is quite shocking," said White.
The action plan will work through the existing backflow prevention grant program, move forward with the immediate implementation of a proactive program to find and remove inflow and infiltration.
The development of a long term infrastructure master plan will be funded immediately and an associated reserve fund, as part of the 2023 budget process, will be developed at the discretion of Sarnia's chief administrative officer.
The collection of flood damaged materials will continue into this weekend because of the volume of requests.
Residents who didn't register before August 10 can sign up until Monday, August 15, at 4:30 p.m.
Individuals requiring curbside removal are asked to call city hall at 519-332-0330 or email customerservice@sarnia.ca with their address.