A storm connection is a pipe that carries stormwater from a property into the City’s sewer system.

Under Chapter 681 of the Toronto Municipal Code (the Sewers By-law), a storm connection from a property cannot be made to the storm or combined sewer. This is to help reduce the amount of stormwater in the sewer system, which in turn will help reduce:

  • Sewer back-ups that cause basement flooding.
  • The release of polluted stormwater into our local waterways.
  • The amount of stormwater processed at wastewater treatment plants.

Residents and businesses should explore ways other than sewer connections to manage their stormwater; however, a property may be eligible for storm sewer connection exemption(s) to allow storm connection(s) to the municipal storm or combined sewer, if:

  • The City determines that keeping the stormwater on site will create a hazard, and/or
  • Managing stormwater on-site is not feasible due to one or more of the following reasons:
    • downspouts are inside the walls of the building.
    • downspouts cannot be physically moved due to heritage designation.
    • the footprint of building has no setback from the edge of the property line.
    • there is limited area for landscaping and infiltration due to the footprint of the building.
    • runoff discharges onto neighbouring property or a public sidewalk and cannot be redirected.
    • there is potential for runoff to flow towards the building foundation.
    • there is potential for runoff to cause erosion, an unstable slope condition, water ponding or basement flooding.
    • there is high groundwater table or soil conditions, which will reduce the effectiveness of on-site stormwater management.

A Storm Connection Exemption Application is required when a new or upsized storm connection to the storm or combined sewer is proposed, or when an existing connection is required to be replaced due to substantial demolition of an existing building, as defined in the Sewers By-law (Municipal Code, Chapter 681). An existing building is considered substantially demolished when more than 50 per cent of the exterior walls of the first storey above grade are removed, whether or not they are subsequently replaced.

Storm Connection Circumstances Storm Connection Exemption
No construction or reconstruction is occurring at the site and a new or upsized storm connection is proposed to the storm or combined sewer system. Required
No construction or reconstruction is occurring at the site and an existing storm connection to the storm or combined sewer is being replaced with a connection of the same size. Not required
Building demolition is occurring at the site which does not include substantial demolition and a new or upsized storm connection is proposed to the storm or combined sewer system. Required
Building demolition is occurring at the site, which does not include substantial demolition and an existing storm connection to the storm or combined sewer is being replaced with a connection of the same size. Not required
A new building is being constructed at the site or a building is being substantially demolished, and a new or upsized storm connection is proposed to the storm or combined sewer system. Required
A new building is being constructed at the site or a building is being substantially demolished, and an existing storm connection to the storm or combined sewer is being replaced. Required

A connection is considered new if it is not replacing a previous connection from a property to the same sewer. An upsized connection refers to the replacement of a connection from a property to the same sewer, but with a larger pipe.  A replaced pipe refers to the replacement of a connection from a property to the same sewer with a same size pipe.

Submission of an exemption application does not guarantee an exemption will be granted.

Please do not begin this process until you have reviewed, understood and prepared the required supporting documentation, including technical reports and drawings, and are prepared to pay the Technical Review fee.

Review timelines will not commence until a complete application is submitted. For an application to be considered complete, the following must be received by the City:

For any clarification on the submission requirements and/or application, contact Victoria Crowther via email at Victoria.Crowther@toronto.ca.

To begin the process, you must submit the completed Municipal Services Application Form to the Toronto Water counter via email at TWC@toronto.ca and be prepared to pay the Technical Review fee. For information on fees, please refer to Wastewater Fees – Technical Review by Toronto Water staff – Application to Toronto Water for new connection or change or alteration to the existing storm connection, sanitary or water supply connection.

The Toronto Water counter will contact applicants to arrange for payment of the Technical Review fee.

  • Accepted forms of payment:
    • credit cards – Visa, MasterCard and American Express;
    • certified cheques; or
    • bank drafts.

Please provide the property owner and agent/applicant contact information to Toronto Water at the time of payment.

After you have submitted the Municipal Services Application Form and paid the Technical Review fee, you will be contacted within five business days by Toronto Water review staff to provide the technical supporting documentation for the application.

Documents needed to start the Technical Review include:

1. Stormwater Management Report prepared, stamped, signed and dated by a professional engineer, licensed to practice in the province of Ontario.

The Stormwater Management Report must, at a minimum, include the following information:

  • Clear justification for why a direct storm connection is required for the site and demonstration that there is no practical alternative means of drainage available.
  • Identify the water type, i.e., stormwater runoff and/or groundwater, intended to be discharged to the municipal sewer.
  • Recommendations for managing the water and proposed designs to control water balance, water quality and discharge criteria to municipal infrastructure in accordance with the requirements summarized in Table 7 of the City’s Wet Weather Flow Management Guidelines.
  • Regardless of type and size of the site, all applications must comply with the “Sewer Connections” and “Discharge Criteria to Municipal Infrastructure” requirements outlined in Row 1 of Table 7 of the City’s Wet Weather Flow Management Guidelines.
  • Site grading and drainage map of the pre-development conditions with the sub-drainage area IDs, area sizes, runoff coefficients, overland flow directions of surface flows onto and off the property and site drainage outlets.
  • Conclusions on the proposed design and its impact on adjacent properties and the natural environment.
  • For applications where there is a proposed connection from the drainage collection system of a reverse slope driveway to the City’s sewer system, ensure technical requirements outlined on the Toronto Water Technical Reviews for Reverse Slope Driveways webpage are satisfied, for both residential and non-residential buildings.
  • For applications proposing to discharge groundwater to the sewer system, the report shall confirm that on-site management of foundation drainage is not technically feasible and that long-term discharge is required to avoid hazardous impacts.
  • For applications for industrial, commercial, institutional, or multi-unit residential sites, where groundwater will be discharged to the sewer system, the report shall include the following items:
    • Confirmation that the lowest elevation of any structure will be higher than the maximum anticipated groundwater level.
    • Please note that if the lowest elevation of any structure will be lower than the maximum anticipated groundwater level, a Private Water Discharge Approval application shall be made.

2. Servicing Report prepared, stamped, signed and dated by a professional engineer licensed to practice in the province of Ontario. The report should include, at a minimum, the following information:

3. 1:100 Site Storm Connection Plan prepared, stamped, signed and dated by the same professional engineer preparing the Stormwater Management Report.

The Site Storm Connection Plan(s) must show the plan and profile of the proposed storm connection system, service connection design and the site drainage map under post-development condition. The storm connection design must be in compliance with the City’s Design Criteria for Sewers and Watermains.

4. Site Topographic Survey Plan prepared, stamped, signed and dated by a qualified surveyor.

Submission of an exemption application does not guarantee an exemption will be granted.

Considerations before applying:

  • Should submission requirements not be met as outlined above, an application will be deemed incomplete. The review and associated response timelines will not begin until the application is complete.
  • Complex applications may require more information to support the exemption application, as determined by Toronto Water staff.
  • The response time after the submission of the first complete application is four to six weeks.
  • The response time after the submission of revisions is 10 business days for each required revision.

Toronto Water will review the submitted materials and if the application meets the conditions necessary for approval, an approval letter will be issued within 10 business days of the final submission.  Toronto Water will approve the report and design drawings and provide a copy to the applicant so that the applicant can have verification of the approval.

Refer to the approval letter for contact information and details on the storm service connection installation process. The City, at the owner’s cost, shall carry out the storm connection(s) within the public right-of-way.

Single family residence

Commercial, institutional or multi-unit residential

  • The installation date is coordinated with the applicant after the City has established the fee for the work and the applicant has paid for the service installments.