Rainwater management on private property

Requirements

Applicability
Most new buildings must provide on-site rainwater management. There are 2 compliance pathways based on site area and floor space ratio (FSR) for projects:
- Up to 1.0 FSR on sites up to 1,000 m² (about 10,760 sq ft) - follow the small site pathway
- Exceeding 1.0 FSR, sites greater than 1,000 m², or both - follow the engineered pathway
Floor space ratio (FSR) is defined by the Zoning and Development By-law, and the value used is after applicable exclusions. All housing options in the R1-1 zone (1.4 MB) are within 1.0 FSR. Review our zoning map

Exemptions

Exempt from these requirements are:
- Laneway houses and infill added to a site with an existing building, where the site area is no greater than 1,000 m². Review the Zoning and Development By-law definitions (912 KB). (Where the site area is greater than 1,000 m², the engineered pathway applies.)
- Accessory buildings - Review the Zoning and Development By-law definition (912 KB)
- Float homes and marinas - Review the Building By-law definitions (1.4 MB)
- Retaining structures
- Temporary buildings - Review the Building By-law Book I, Division C, Subsection 1.6.8. (9.6 MB)
- Alterations to existing buildings - Review the Building By-law Book I, Division B, Sentence 11.1.3.1.(2) (9.6 MB)
Relaxations

Site conditions may prevent excavation and full compliance with the on-site rainwater management requirements.

Learn how we may relax these requirements in the Building By-law (Book II, Division B, Note A-2.4.2.5.(9)) (1.4 MB)

Small site pathway

Buildings showing gutters, landscape features, rainwater detention tank, and stormwater tank

Most new projects up to 1.0 FSR and on sites up to 1,000 m² are subject to the rainwater management requirements of the “small site pathway.” Review the applicability section for exclusions.

This requires the installation of a rainwater detention tank based on site area:

Site area	Minimum active storage capacity	Orifice plate diameter
Up to 400 m²	3,400 L	30 mm
400.1 to 500 m²	3,900 L	35 mm
500.1 to 750 m²	4,600 L	45 mm
751.1 to 1000 m²	7,200 L	50 mm

Suppliers providing rainwater detention tanks (90 KB)

Specifications

The “minimum active storage capacity” excludes the volume below the orifice and above the emergency overflow. It is not the same as the overall volume of the detention tank.

The detention tank must be able to support the design depth of cover and surface loads. Review the requirements in the Building By-law (Book II, Division B, Article 2.4.2.5.) (1.4 MB), (Notes) (1.4 MB)

Compliance will be verified at the plumbing inspection stage.

Managing surface water flows

For new homes, surface water flows must be contained and managed on the same property. Rainwater collected on pavement or concrete (such as on driveways, parking pads, and patios) must not be directed to neighbouring properties.

Grade differences between adjacent lots can also create drainage problems. This can be controlled with a retaining wall and drain tile system along the elevated areas.

Infiltration

For rainwater infiltration practices, there are minimum setbacks from buildings and neighbouring properties. Review the requirements in the Building By-law Book I, Division B, Article 9.14.5.3 (5.3 MB), (Notes) (5.3 MB)

Engineered pathway
Most new projects greater than 1.0 FSR, on sites greater than 1,000 m², or both, are subject to the rainwater management requirements of the “engineered pathway.” Review the applicability section for exclusions. Review the requirements in the Building By-law (Book II, Division B, Article 2.4.2.5.) (1.4 MB)

Compliance will be verified at the plumbing permit application stage.

Plumbing permit

The plumbing permit application is submitted online and must contain:
- Project Summary form:
  - Project Summary form for building permits opened in 2026 (132 KB)
  - Project Summary form for building permits opened before 2026 (145 KB)
- Site schematic showing rainwater management and drainage components (example of a site schematic (560 KB)). The Project Summary form may be included on the same page as this schematic.
- Design drawings, supporting calculations, and references
- Schedule B from the plumbing registered professional of record and the civil registered professional of record (if not already submitted at the building permit application stage)
For guidance on Schedule B, refer to the Province’s Guide to the Letters of Assurance (section 22.2) .

An operations and maintenance manual must be provided to the owner. It doesn't need to be submitted to the City for review or approval. Review the requirements for the operations and maintenance manual in the Building By-law (Book II, Division B, Article 2.2.1.9 (1.4 MB))
Storm sewer connection

Sewer depth

The location and depth of the storm sewer connection are determined through the sewer connection permit process. Typically, the depth of cover is 1.52 m for low-density residential development and may be up to 2.4 m for complex buildings.

In some cases, this may prevent gravity drainage of a detention tank. To accommodate a gravity connection, you can request a deeper storm invert by emailing [email protected]. This request may be submitted as early as at the development permit stage. There is no guarantee that a deeper connection can be supported, as local constraints may limit the maximum permissible connection depth.

Reference: City of Vancouver Engineering Design Manual (section 5.6.3) (9.9 MB)

Sewer discharge

Review water quality standards for discharged storm water in the Sewer and Watercourse By-law (section 3) (346 KB).
Reference documents

In-stream applications

Generally, the date that a building permit (BP) is opened establishes the version of the Building By-law applicable to a project.

The date that a permit is "opened" is seen as the "application date" in our online portal. Search for a permit

For applications that have transitioned from previous rainwater management requirements, email [email protected] to confirm the requirements.

Some developments may have site-specific rainwater management requirements. Review other requirements

Building permits opened after January 1, 2026
Building permits opened between September 15, 2025, and December 31, 2025
Rainwater management requirements

For building permits opened between September 15, 2025, and December 31, 2025, refer to the 2025 Vancouver Building By-law (1.4 MB) (By-law 14343), Book II, Division B, Article 2.4.2.5.

Exceptions

These requirements may not apply to some applications:
- If a development permit (DP) was opened before January 1, 2025 for:
  - A Part 9 building, or
  - A building used exclusively for residential occupancy containing no more than 8 principal dwelling units.
- If a rezoning application or DP was applied for before January 1, 2024, and no rainwater management plan was required.
For full criteria, refer to 2025 Vancouver Building By-law Book I, Division C, Article 3.3.1.3 (9.6 MB).
Building permits opened between July 1, 2025, and September 14, 2025
Rainwater management requirements

For building permits opened between July 1, 2025, and September 14, 2025, refer to the 2019 Vancouver Building By-law (By-law 12511, amended by By-laws 13760, 14078, and 14344), Book II, Division B, Article 2.4.2.5.

Exceptions

These requirements may not apply to some applications:
- If a development permit (DP) was opened before January 1, 2025 for:
  - A Part 9 building, or
  - A building used exclusively for residential occupancy containing no more than 8 principal dwelling units.
- If a rezoning application or DP was applied for before January 1, 2024, and no rainwater management plan was required.
For full criteria, refer to 2025 Vancouver Building By-law Book II, Division C, Article 3.3.1.3
Building permits opened between July 1, 2024, and June 30, 2025

Rainwater management requirements

For building permits opened between July 1, 2024, and June 30, 2025, refer to the 2019 Vancouver Building By-law (By-law 12511, amended by By-laws 13760 and 14078), Book II, Division B, Article 2.4.2.5.

Exceptions

These requirements may not apply if a rezoning application or development permit (DP) was applied for before January 1, 2024, and no rainwater management plan was required.

For full criteria, refer to 2019 Vancouver Building By-law Book II, Division C, Article 3.3.1.3.
Building permits opened between January 1, 2024, and June 30, 2024

Rainwater management requirements

For building permits opened between January 1, 2024, and June 30, 2024, refer to the 2019 Vancouver Building By-law (By-law 12511, amended by By-law 13760), Book II, Division B, Article 2.4.2.5.

Exceptions

These requirements may not apply if a rezoning application or development permit (DP) was applied for before January 1, 2024, and no rainwater management plan was required.

For full criteria, refer to 2019 Vancouver Building By-law Book II, Division C, Article 3.3.1.3.
Building permits opened before January 1, 2024
Other requirements

First Shaughnessy

For new developments in First Shaughnessy with a building permit (BP) opened before January 1, 2026, area-specific rainwater management requirements apply, as defined in the First Shaughnessy District Schedule. For BPs opened on or after January 1, 2026, the Building By-law requirements apply.

Rezoning or DP applications submitted before 2024

For new developments where a rezoning application or development permit (DP) was applied for before January 1, 2024, and a BP is not opened before January 1, 2026, the project must meet the Building By-law rainwater requirements that are in effect when the BP is opened.

If a rainwater management plan had been conditioned, that condition no longer applies.

Rezoning approvals with site-specific rainwater requirements

Certain rezoning approvals may include site-specific rainwater management requirements. In some cases, applicants may have also agreed to more stringent rainwater criteria in exchange for removing sewer upgrade requirements.

Where such site-specific rainwater management requirements have been required or agreed to, these will continue to apply in addition to the Building By-law requirements. If you have questions about how such requirements align with the Building By-law, email [email protected].

Sewer upgrade conditions

To request consideration for the elimination of a sewer upgrade condition in exchange for adoption of the 2026 engineered pathway rainwater management criteria, email [email protected].

Questions?

Email: [email protected]

Background

Purpose
In Vancouver, rainwater directed into our sewer system can cause flooding and sewer overflows.

Alongside coordinated sewer system upgrades, private property rainwater management will enable housing development to proceed by helping to relieve sewer system capacity constraints. It will also help to meet regulatory obligations.

References
- Combined sewer overflows in the city of Vancouver
- Basin characterization maps (8.1 MB) in the city of Vancouver
- Real-time sewer overflow map from Metro Vancouver
- Beach water quality map from Vancouver Coastal Health
Tools
The preferred rainwater management tools are those that integrate natural systems, reduce the volume of rainwater entering the sewer system, and control the rate of rainwater release from a site:
- Landscape-based solutions can allow rainwater to soak into the ground or return to the atmosphere
- Non-potable water systems can use rainwater instead of drinking water for applications like toilet flushing. They can also help to reduce water and sewer utility bills. Learn more about non-potable water system requirements
- Vegetated roofs (green roofs) can absorb rainwater, allow some to return to the atmosphere, and slow down runoff into the sewer system. Information icon New standards for vegetated roof installations came into effect on July 1, 2024. Learn more about green roofs
  - Reference documents:
    
    Vancouver Building By-law, Division A, Section 1.4 (9.6 MB), (Notes) (9.6 MB)
    
    Vancouver Building By-law, Division B, Article 3.1.14.4 (9.6 MB)
    
    Vancouver Building By-law, Division B, Article 5.2.2.2 (9.6 MB), (Notes) (9.6 MB)
    
    Vancouver Building By-law, Division B, Section 5.6 (9.6 MB), (Notes) (9.6 MB)
Learn more about green rainwater infrastructure

To reduce the volume of sanitary sewage entering the sewer system (and to reduce the use of drinking water), we have water efficiency requirements (160 KB) for plumbing fixtures and mechanical equipment.
Program results
As of September 2025, 192 new developments with issued building permits will meet the on-site rainwater management requirements. In total these will:
- Manage 66 hectares (for comparison, Queen Elizabeth Park is 53 hectares)
- Reduce peak rainwater runoff by about 7,400 litres per second (for comparison, review Capilano and Seymour River flow rates)
- Add 72 new green roofs totalling 3.6 hectares (for comparison, Nanaimo Park is 2.9 hectares)
- Add 5 new building-scale rainwater harvesting (non-potable) water systems for flushing toilets and other uses (Review map of existing non-potable water systems)
Additionally, many of these developments will provide public green infrastructure like trees, bioretention curb bulges, and infiltration trenches along the right-of-way. Learn more about public green infrastructure
Regulatory history
Rainwater management

Council approved streamlined rainwater management requirements (696 KB) in July 2023. This immediately simplified the:
- Green Buildings Policy for Rezonings (246 KB) and associated Bulletin (121 KB)
- Rezoning Policy for Sustainable Large Developments (1.1 MB) and associated Bulletin (427 KB)
Additional changes took effect on January 1, 2024:
- Zoning and Development By-law: rainwater management requirements were removed from sections 4.3.4, 4.3.5, and 4.3.6 and the Rainwater Management Bulletin is no longer being used.
- Vancouver Building By-law
A memorandum about the transition process for in-stream applications (375 KB) was sent to City Council on November 30, 2023. A memorandum about expanding rainwater management requirements (187 KB) was sent to City Council on June 11, 2024.

Council approved on-site rainwater management requirements for most new buildings, effective July 1, 2025. Review the Council Report from November 12, 2024 (403 KB)

Council approved enhanced on-site rainwater management requirements under the engineered pathway, effective January 1, 2026, and eliminated area-specific rainwater management requirements from the First Shaughnessy District Schedule and various CD-1 by-laws. Review the Referral Report from August 19, 2025 (563 KB)

Tools

New requirements for vegetated roof assemblies (green roofs) took effect on July 1, 2024, in the Vancouver Building By-law. Review the Council Report (431 KB)

Council expanded opportunities for non-potable water systems, allowing for the use of residential scale greywater re-use systems certified to NSF 350 Class R within the 2025 Vancouver Building By-law (11 MB)

Find Council decisions

Rainwater management on private property (drainage)

What you need to know

Requirements

Applicability

Small site pathway

Engineered pathway

Storm sewer connection

Reference documents

In-stream applications

Building permits opened after January 1, 2026

Building permits opened between September 15, 2025, and December 31, 2025

Building permits opened between July 1, 2025, and September 14, 2025

Building permits opened between July 1, 2024, and June 30, 2025

Building permits opened between January 1, 2024, and June 30, 2024

Building permits opened before January 1, 2024

Other requirements

Background

Purpose

Tools

Program results

Regulatory history

Contact us

Contact information, partner agencies, and website policies