A reverse slope driveway is a driveway that slopes down from a public street to a parking area, such as a below-grade (underground) garage.
The City’s zoning bylaws prohibit building garages with reverse slope driveways for certain types of residential buildings in the city, including:
- detached houses
- semi-detached houses
- individual townhouse dwelling units where an individual private driveway leads directly to the dwelling unit
To build a garage with a reverse slope driveway, you must apply for an exemption through either a Minor Variance Application or Zoning By-law Amendment Application depending on your development type.
As part of this process, you may also need to apply for a Toronto Water technical review if any of the following apply:
- 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
- the City requests a technical review through the re-zoning application process
- your application proposes a storm connection to the City’s sewer system to discharge water from the reverse slope driveway’s drainage collection system
- In this case, you must include a Storm Connection Exemption Application with your technical review application for a reverse slope driveway.
- The Sewers By-law requires drainage collection systems for reverse slope driveways to discharge stormwater at grade, away from the building, so that stormwater will not accumulate at or near the building and will not adversely affect neighbouring properties.
Applying for a technical review does not guarantee approval will be granted.
Apply for a Toronto Water Technical Review
Do not begin this process until you have reviewed, understood and prepared the required supporting documents, and you are prepared to pay the technical review fee.
For questions on submission requirements or the application process, contact Victoria.Crowther@toronto.ca.
- Submit a completed Municipal Services Application Form to TWC@toronto.ca. If someone other than the property owner is submitting the application, the owner must provide a letter that authorizes the agent to apply on their behalf.
- Review staff will contact you to request the required supporting documents for your application.
- After receiving your supporting documents, staff will request that payment be made to TWC@toronto.ca for the technical review fee. The fee is listed as “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”. Accepted forms of payment include:
- credit cards (Visa, MasterCard and American Express)
- certified cheques
- bank drafts
- Staff will review the submitted materials and provide comments.
- If approved, you will receive an approval letter. You will also receive copies of the approved report and design drawings for your records.
Required Supporting Documents
To apply for a technical review, you will need to provide the following supporting documents:
- topographic survey prepared, signed and dated by a qualified surveyor
- reverse slope driveway report and related design drawings prepared, stamped, signed and dated by a professional engineer, licensed to practice in Ontario
- copy of the conditional approval of the Committee of Adjustment or Ontario Land Tribunal’s decision (if applicable)
For report submission requirements and limitations for reverse slope driveways, refer to Appendix F of the Design Criteria for Sewers and Watermains.
Be sure to address all requirements in Appendix F, including but not limited to:
- demonstrating that the drainage from the surrounding area will not contribute to flooding of the reverse slope driveway using supporting calculations
- providing a cross-section with spot elevations of the reverse slope driveway from the garage through the right-of-way
- providing an existing and proposed site grading and external drainage area plan with spot elevations and the proposed driveway drainage collection and discharge system
- if proposing a connection from a reverse slope driveway’s drainage collection system to the storm sewer system, demonstrating in the report that:
- discharging at grade would create a hazardous condition or is not technically feasible
- 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 will 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 installed 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
- your application meets all requirements outlined on the Storm Connection Exemption Application page
Review Timelines
Review timelines begin only after you have submitted a complete application.
Your application is considered incomplete if you do not meet the submission requirements outlined under Required Supporting Documents and from Appendix F of the Design Criteria for Sewers and Watermains. More information may be required to support the application as determined by Toronto Water review staff.
| Submission |
Review Timeline |
| After submitting the first complete application |
Four to six weeks |
| After submitting revisions |
10 business days for each revision |
