A reverse slope driveway is one that slopes downward from a public street to a parking area, such as a below-grade garage.

  • The City of Toronto’s Zoning By-Law 569-2013 prohibits the construction of garages with reverse slope driveways for certain types of residential buildings in the city. This applies to detached houses and semi-detached houses, and to individual townhouse dwelling units, where an individual private driveway leads directly to the dwelling unit.
  • If you want to build a below-grade garage that needs a reverse slope driveway, you must apply for an exemption through a Planning Application – either a Minor Variance Application or a Re-zoning Application, depending on your development type.
  • As part of the Planning Application process for a reverse slope driveway exemption, you may also be required to submit an application for a Toronto Water Technical Review of the reverse slope driveway, if:
    • The Committee of Adjustment’s Notice of Decision or decision by the Ontario Land Tribunal (OLT, previously the Local Planning Appeal Tribunal or Ontario Municipal Board) requires a technical review and approval by Toronto Water.
    • A technical review is requested through a re-zoning application approval process.
    • The application proposes a storm connection to the City’s sewer system to discharge water from the reverse slope driveway’s drainage collection system. The City of Toronto Sewers By-law (Municipal Code, Chapter 681) requires that:
      • ‘Where a catch basin or similar drainage collection system has been installed or is proposed to be installed on private property to drain stormwater from a reverse slope driveway towards any residential building located on the property, the stormwater from the drainage collection system shall be discharged at grade, away from the building, in such a manner that the stormwater will not accumulate at or near the building and will not adversely affect adjacent properties.’

Submission of an application for a Toronto Water Technical Review does not guarantee an approval will be granted.

If a proposed or existing reverse slope driveway will not be discharging to grade and needs a storm connection to a City storm sewer, a Storm Connection Exemption will be required. An exemption will only be considered if discharging to grade would create a hazardous condition or is not technically feasible. Applicants should carefully review the City of Toronto Sewers By-law and the Storm Connection Exemption Application webpage for information on requirements in order to determine if the site is eligible for a storm connection and understand the additional submission requirements that will apply to the storm connection design. The Storm Connection Exemption Application can be included in the same application form as the request for a Toronto Water Technical Review for a Reverse Slope Driveway.

Please do not begin this process until you have reviewed, understood and prepared the required supporting documentation, including technical reports and drawings and a complete Municipal Services Application Form, 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, please contact Victoria Crowther via email at Victoria.Crowther@toronto.ca.

To begin the process, you must submit a completed Municipal Services Application Form to the Toronto Water counter via email at TWC@toronto.ca and 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 an exemption to permit the construction of a driveway sloped downwards towards a residential building.

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 coordinate the provision of technical supporting documentation for your application.

Documents needed to start the Technical Review include:

1. Topographic Survey, prepared, signed and dated by a qualified surveyor.

2. Reverse Slope Driveway Report and related design drawings prepared, stamped, signed and dated by a professional engineer, licensed to practice in the province of Ontario.

For minimum report submission requirements and limitations for reverse slope driveways, refer to Appendix F of the Design Criteria for Sewers and Watermains – Reverse Slope Driveway Guidelines. Special consideration should be taken to include all of the requirements in Appendix F, including but not limited to:

  • demonstration that the drainage from the surrounding area will not contribute to flooding of the reverse slope driveway using supporting calculations;
  • a cross-section with spot elevations of the reverse slope driveway from the garage through the right-of-way; and
  • existing and proposed site grading and external drainage area plan with spot elevations and the proposed driveway drainage collection and discharge system.

If a connection is proposed from a reverse slope driveway’s drainage collection system to the storm sewer system, the report must demonstrate that discharging at grade would create a hazardous condition or is not technically feasible. In addition, the report shall demonstrate the following:

  • a storm sewer must be present immediately adjacent to the subject property, which has capacity to handle any additional stormwater flow resulting from the proposed connection;
  • the storm sewer connection shall have no detrimental effects to the storm drainage system;
  • a flap gate backwater valve is installed upstream of the public portion of the sewer connection at the street line, so that no stormwater may back up from the City storm sewer into the private drainage collection system;
  • a sump pump is located in the overflow sump, to discharge any stormwater which has collected in the drainage collection system while the flap gate backwater valve has closed, to prevent a backup of stormwater;
  • the sump pump and any required storage system are appropriately sized to drain the collection area and prevent flooding into the building; and
  • any requirements outlined in the City’s Storm Connection Exemption Application webpage are satisfied

3. Copy of the conditional approval of the Committee of Adjustment or Ontario Land Tribunal’s decision (if applicable).

Submission of an application for a Toronto Water Technical Review does not guarantee an approval will be granted.

Considerations before applying:

  • Should submission requirements not be met as outlined above and in the Reverse Slope Driveway Guidelines in Appendix F of the Design Criteria for Sewers and Watermains, the application will be deemed incomplete and the review and associated response timelines will not begin.
  • More information may be required to support the application as determined by Toronto Water review 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 ten business days for each 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 ten business days of the final submission.  Toronto Water will approve the report and design drawings and provide a copy to the applicant so they can have verification of the approval.