Drains & Sewers

Larvicide Placement in Catch Basins of Storm Drains

Between June 19 and October 31, 2023, the City of Barrie is conducting a larviciding program under the authority of the Local Medical Officer of Health to control larval mosquitoes in order to prevent their development into vectors of West Nile Virus. The pellet formulation of Altosid Methoprene Pellets Mosquito Growth Regulator PCP#21809 or the pouch formulation of Vectolex WSP Biological Larvicide PCP#28009 will be placed into municipal owned catch basins of storm drains within the boundaries of the City of Barrie.

All larvicide will be applied by applicators, licensed by the Ministry of the Environment, Conservation and Parks, or their supervised technicians. Municipal owned catch basins on private property (rear Lot Catch Basins) will be treated upon request of the homeowner with Altosid XR Briquette PCP#27694. A consent form must be signed by the homeowner prior to treatment.

For additional details on the locations and dates of treatment please call (705) 739-4219.

Learn about West Nile Virus Prevention

Prior to the commencement of the larviciding program, the City cleans out all catch basins, which ensures that they are free of sediment and water and that the larvicide will remain in place for the appropriate time period and will not be flushed out. Additionally, the contractor does not apply the larvicide during rain events and uses a calibrated dispensing tool to ensure there are no excess amounts of larvicide. These methods prevent the larvicide from being flushed out of the intended catch basins and into the waterway.

There are two types of sewer systems: storm and sanitary.

The municipal storm sewer system collects rainwater and surface water runoff from roads and parking lots. The municipal sanitary sewer system is a system of underground pipes that transport sanitary sewage from the plumbing of privately owned buildings to the Wastewater Treatment Facility.

Flooding can occur if the sewer connection to a building becomes blocked, or when catch basins or culverts are blocked. 

Sewers diagram

Sewer Use By-law

The Sewer Use By-law prohibits, regulates and inspects the discharge of water and sewage into Barrie’s sanitary and storm sewers. The by-law establishes limits for water quality parameters. 

Storm Sewer System

The municipal storm sewer system collects rainwater and surface water runoff from roads and parking lots into natural channels and catch basins (storm grates) and transports it to various points in Kempenfelt Bay.

Water that enters a storm drain is NOT treated to remove pollutants; it is important not to dispose of any waste materials into any storm water collection point. Please help protect our drinking water sources.

Oil Grit Separator (OGS) units are included in most newer storm sewer designs, but not all areas of Barrie have OGS units. These units can remove suspended solids from stormwater. There is a limited capacity in most OGS units to capture floating contaminants (oils, gasoline, etc.). Routine maintenance empties these units of sediment and oils, and emergency cleanouts can be required.

Pilot Program: LittaTraps Installation

The City of Barrie has installed LittaTraps in catch basins, undertaking a pilot program to catch litter before it enters city select storm​water drains, to help protect Lake Simcoe.

Sanitary Sewer System

The municipal sanitary sewer system is a system of underground pipes that transport sanitary sewage from the plumbing of privately owned buildings to the Wastewater Treatment Facility (WwTF). Manholes are used at designated intervals in a sewer line as a means of access for inspection or cleaning.

The sewage is treated at the WwTF and clean treated water is discharged into Kempenfelt Bay. To ensure a properly functioning transportation and treatment system, certain materials should NOT be disposed into sinks or toilets.

When disposed of into sinks or toilets, these common items can cause blocked drains, equipment damage, injury to a WwTF employees, and/or poor sewage treatment:

Disposable diapersAny plastic materials
Baby wipes or toysKitchen grease
Sanitary napkinsOil, fuels & other hazardous materials
Combs or brushesBuilding foundation drainage (sump pump water)
HairNewspapers, rags, cloths, cleaning wipes, paper towels

If you have water coming back up your drains (i.e. basement floor drain) you may have a blocked drain. To help avoid a common cause a blocked lateral, please review Grease Management for your Home.

City crews can determine whether the blockage is in the main or in the homeowner's sewer lateral. If the blockage is in the main that runs down the middle of the street, the City is responsible for clearing it.

It is City policy when responding to calls regarding blocked sewers to check the main, whether the caller thinks the blockage is their responsibility or not.  If the main is blocked it could affect more than one property. Once it has been verified that the blockage is not in the main, the homeowner should call a​​ private service provider.

Sanitary lateral

Keeping Track of Underground Infrastructure

Staff monitor the sanitary and the storm sewer systems to help prevent issues and plan for future repairs: 


Flooding can occur if the sewer connection to a building becomes blocked by tree roots, grease, objects and other debris. Flooding can also occur during spring and summer storms and also when catch basins or culverts are blocked. Basic preventative measures include:

  • do not put grease or objects (such as diapers, wipes, paper towels, rags, dental floss) down your toilet or drains.
  • consider installing a sump pump if required. 
    Sump pumps are installed in the basement of homes to collect water from the foundation of the house and pump it out onto the lawn to prevent basement flooding.
  • keep catch basins clear of leaves and debris. In the fall, sweep up leaves for bagging or composting to prevent excess debris from entering the sewer system.
  • consider having your plumbing cleared of any debris, roots, etc.

If you have a back-up of water and/or sewage in your basement, please:

  • Check the toilets and sinks and clear any blockages.
  • If that doesn’t solve the problem, please call us at 705-726-4242.
  • Avoid using your plumbing until the problem has resolved to minimize any damage.
  • Make notes of everything that happens (i.e. where and when the water came in, anything you did to help alleviate the flooding). This will help City staff or your plumber determine the cause of the flooding.

It is important that any obstructions that can contribute to flooding be reported to the City of Barrie as soon as possible. Call 705-726-4242.

During spring weather conditions and heavy rainfall events, water levels in local creeks and watercourses can rise and be dangerous. Please call the City at 705-726-4242 (after-hours, please follow the prompts) to report any of the following:

  • obstructions in creeks or watercourses
  • flooded ditches
  • blocked culverts
  • flooded roadways