Sewer services in St. Catharines are maintained and operated through shared responsibility by the City of St. Catharines, Niagara Region and property owners.
Residential and commercial properties have private sewers within each property that connect to City-owned main sewers. The City's main sewers receive sewage from these private sewers and drain to large trunk sewers, which carry wastewater to sewage treatment plants.
Responsibilities and roles
Property owners are responsible for sewer service from the property line to their building and the City is responsible for all sewer services and mains on public property. Niagara Region operates and maintains trunk sewers and sewage treatment plants. City staff perform routine camera inspection and cleaning of the city's main sewers.
Sewer back-ups
If you experience water coming up through your floor drain, either during or following a rain storm, or while using large amounts of water (such as when washing laundry), you may have a blocked sewer service or sewer back-up.
Addressing the back-up
To address the back-up, you can either:
- Call a private contractor or plumber to perform the repair. If you hire the contractor or plumber, you will be responsible for their costs regardless of where the blockage is located.
- Call our staff at 905.688.5600 to have a City crew respond to your issue and take appropriate measures to correct the problem. The cost to have City staff perform repairs is determined by:
- The nature of the blockage
- The location of the blockage in relation to your property line
- The equipment used to clear the blockage
Please follow these safety guidelines when having the City inspect the blockage:
- Ensure you have provided clear access to the sewer service clean-out. City staff cannot move personal property.
- Restrain pets inside your home.
- Place material down to protect floors. City staff cannot remove their boots.
Blockages within private property
If the blockage is found to be within the private property portion of your sewer service, the property owner is responsible for all costs to clear the blockage.
Blockages beyond the private property line
If the blockage is found to be within the main sewers beyond your property line, there is no cost associated with repairs to the property owner.
However, if there is not adequate access to the sewer service from an appropriate sewer service clean-out (either inside or outside the building) to allow for the use of sewer cleaning rods, the property owner is responsible for all costs to clear the blockage, regardless of its location. The absence of a proper clean-out limits our ability to thoroughly clear the sewer blockage. This is particularly important if the cause is due to tree roots or grease build-up.
Sewer inspections
Our plumbing inspectors examine new sanitary and stormwater sewers on private property to ensure compliance with plumbing regulations set out in the Ontario Building Code before service is connected. We also inspect all new sewer services installed on public roads or within city easements.
Learn more about connecting your private service to the City's sewer system and scheduling an inspection.
Types of sewers in the city
There are a few different types of sewers in St. Catharines, used for different purposes.
Sanitary sewers and combined sewers
Sanitary sewers carry wastewater from residential, commercial and industrial sources. Combined sewers carry both wastewater and stormwater.
During dry weather, both sanitary and combined sewers transport wastewater to either the Port Dalhousie or Port Weller sewage treatment plants.
During some wet weather events, the capacity of the sewer system can be exceeded and the wastewater in combined sewers must be directed to large combined sewer overflow tanks. These tanks are used to store wastewater until the levels in the sewer system return to normal, at which point the wastewater is directed back into the sewers and toward a treatment plant.
During prolonged, ongoing wet weather events, overflow tanks may reach capacity, at which point they are designed to overflow to the nearest body of water. Our staff closely monitor these events to ensure minimal environmental impact.
A copy of the 2023 Annual Report on the St. Catharines wastewater collection system can be found here.
Storm sewers
Storm sewers carry rainwater and runoff to the nearest body of water to be discharged through points called outfalls. Catch basins collect this water and are positioned along the curbside of streets, connecting to storm sewers. They are also designed to catch debris, such as sand, leaves and dirt, that has washed off the street, and keep this material while allowing rainwater to drain to the storm sewer.
Our staff conduct annual cleanings of catch basins and regular inspections of storm sewer outfalls to ensure they function properly within the storm sewer system.
A copy of the 2023 Annual Report on the St. Catharines stormwater management system can be found here.
Manholes and catchbasins
If you spot a manhole that is raised or missing a lid, please contact us or use our Report an Issue online form.
Catch basin covers can easily become blocked with leaves or snow, leading to flooding issues. You can help keep catch basins clear by never using them to dispose any improper materials or clearing debris from the cover. Contact us or use our Report an Issue online form if you spot flooding issues.