Foundation drainage is groundwater or stormwater that infiltrates the soil and may be collected in a drain installed at the foundation of a structure. When foundation drainage is not managed properly, it can enter City sewers and reduce available sewer capacity.
The City’s Foundation Drainage Policy and Foundation Drainage Guidelines help protect sewer capacity and support future growth by requiring developments to manage foundation drainage on-site instead of discharging it to City sewers.
The Foundation Drainage Policy and Foundation Drainage Guidelines came into effect on January 1, 2022 for new development applications. Amendments to the policy took effect on October 1, 2026.
The Policy and Guidelines apply to all new development applications under the Planning Act (except for Committee of Adjustment applications) or where a zoning requirement is to be satisfied, including the following:
Submitting revised materials under an existing Community Planning Application number is not considered a new application.
| Application Scenario | Do the Foundation Drainage Policy & Guidelines apply? |
|---|---|
| Development applications submitted before January 1, 2022 | No |
| Development applications submitted on or after January 1, 2022 and before October 1, 2026 | Yes – applicants may choose to meet the October 1, 2026 amended policy requirements by resubmitting materials through the development review process. |
| Development applications submitted on or after October 1, 2026 | Yes – the City will review applications under the October 1, 2026 amended policy. |
The table below summarizes when developments require a Private Water Discharge Permit or Agreement.
| Application Scenario | Private Water Discharge Permit or Agreement required? |
|---|---|
| Development applications submitted before January 1, 2022, proposing foundation drainage discharge to a City sewer | Yes |
| Development applications submitted on or after January 1, 2022 that comply with applicable policy statements for long-term foundation drainage discharge | No |
| Development applications proposing short-term foundation drainage discharge for construction dewatering | Yes |
| Development application proposing short-term emergency foundation drainage discharge | Yes – at the time of a future emergency. See Policy Statement 4.5. |
Development applications subject to the Foundation Drainage Policy and Guidelines must include a Foundation Drainage Technical Brief as part of the development application process. The technical brief must include:
The Foundation Drainage Guidelines provide direction on the technical requirements to comply with the Policy, such as for groundwater monitoring and discharge to a Dedicated Storm Sewer.
Applicants seeking to use Policy Statement 4.4 of the amended policy should refer to the Dedicated Storm Sewer maps below to determine eligibility. To identify the ward for your development, use the City’s Ward Profiles tool.
While we aim to provide fully accessible content, there is no text alternative available for the maps at this time. A new digital map with improved accessibility features will be available in the future. If you need assistance reviewing the maps, contact your Development Engineering Case Manager.
The Foundation Drainage Policy – Dedicated Storm Sewer Maps shall solely be used to confirm compliance with the Foundation Drainage Policy, Policy Statement 4.4 (Discharge of Foundation Drainage containing Groundwater). The maps are based on data as of May 19, 2026. The information provided in the maps is solely on an “as is” basis. While the City makes reasonable efforts to provide accurate information, the maps:
The City does not guarantee or make, and to the fullest extent permissible pursuant to applicable law expressly disclaims, any representations, warranties, or conditions of any kind, whether express or implied. This includes, without limitation, any implied warranties of merchantability or fitness for a particular purpose with respect to the information provided.Without limiting the foregoing, the City does not represent or warrant that the information is free of errors or deficiencies of any kind, nor does it make any representation or warranty regarding the content, accuracy, correctness, reliability, currency, or completeness of the information. Furthermore, the City does not warrant the satisfactory quality, fitness, or suitability of the information for any particular purpose.
For proposed buildings or structures that cannot comply with any of the policy statements, the City may, in rare instances, grant exemptions where:
Financial constraints are not a valid reason to support the lack of on-site management.
In addition to the required supporting material, include the following materials with your development application:
In addition to the required supporting material, include a signed letter or Foundation Drainage Technical Brief summarizing project milestones and timing (including submission dates of relevant engineering reports) with your development application.
Applicants granted an exemption must apply for a Private Water Discharge Agreement. To minimize application processing time, applicants should begin the required background studies and reports as soon as possible.
If the conditions for a Private Water Discharge Agreement cannot be met, long-term foundation drainage discharge to City sewers will not be permitted.