Drain & Sewer Connection Permits Toronto 2026
Storm vs Sanitary Systems, TRCA Requirements, Costs & the $3,400 Basement Flooding Rebate
Whether you are connecting a new basement drain to the municipal sewer, installing a backwater valve, re-routing your sump pump discharge, or tying into a storm sewer after grading work, Toronto requires a permit before any pipe touches the city system. Getting it wrong means fines, failed inspections, and flooding that your insurance will not cover. This guide walks you through every permit type, the documents you need, what it costs, and how to claim up to $3,400 back through the City of Toronto Basement Flooding Protection Subsidy.
When Do You Need a Drain or Sewer Permit?
Any Connection to the Municipal System Requires a Permit
Under the City of Toronto Municipal Code Chapter 681 (Sewers) and the Ontario Building Code Section 7, any work that connects to, modifies, or disconnects from the municipal storm or sanitary sewer system requires a plumbing permit from Toronto Building and, in some cases, separate approval from Toronto Water.
The following scenarios all trigger a permit requirement. If your project touches any of these, do not proceed without approval.
Permit Required
- • New storm sewer connections (downspout disconnection, new catch basins)
- • Sanitary sewer tie-ins (new basement bathroom, kitchen rough-in)
- • Backwater valve installation or replacement
- • Sump pump discharge re-routing to grade or storm sewer
- • Site grading changes affecting drainage patterns
- • Weeping tile replacement or new installation
- • Pipe severance (disconnecting foundation drains from sanitary sewer)
Risks of Unpermitted Drain Work
- ✗ Fines of $5,000-$25,000 under Municipal Code Chapter 681
- ✗ Insurance denial for any resulting water damage
- ✗ Forced excavation to expose and correct illegal connections
- ✗ Ineligible for the $3,400 basement flooding rebate
- ✗ Liability for sewer backups affecting neighbouring properties
- ✗ Disclosure requirement when selling your home
Storm vs Sanitary Sewer Systems in Toronto
Understanding the difference between storm and sanitary sewers is critical because connecting to the wrong system is illegal, can cause environmental contamination, and will fail inspection. Toronto operates two distinct sewer networks, plus legacy combined sewers in older areas.
Storm Sewer System
Rainwater & Snowmelt Only
- → Carries rainwater from roofs, driveways, catch basins, and sump pumps
- → Water flows untreated directly to rivers and Lake Ontario
- → Never connect toilets, sinks, or laundry drains to storm sewer
- → Permit issued by Toronto Water for new connections
Sanitary Sewer System
Household Wastewater Only
- → Carries wastewater from toilets, sinks, showers, laundry, and dishwashers
- → Water is treated at wastewater treatment facilities before release
- → Never connect sump pumps, downspouts, or yard drains to sanitary sewer
- → Backwater valve installed on this line to prevent sewage backup
Toronto's Combined Sewer Areas
Older neighbourhoods in Toronto, particularly those built before the 1950s, often have combined sewers where storm and sanitary water share a single pipe. These areas include much of Old Toronto, the Annex, Riverdale, Leslieville, the Junction, and parts of Etobicoke and East York.
The City of Toronto is actively separating combined sewers through its Basement Flooding Protection Program. If your home is in a combined sewer area, your drain permit may require pipe severance, which disconnects your foundation drains from the sanitary sewer. This work is eligible for rebates.
TRCA / Conservation Authority Requirements
The Toronto and Region Conservation Authority (TRCA) regulates development within flood plains, near watercourses, and in environmentally sensitive areas. If your property falls within a TRCA regulated area, you need their approval in addition to your municipal drain permit.
When TRCA Approval Is Needed
- Property within 15m of a ravine crest
- Within a regulatory flood plain
- Near a creek, river, or watercourse
- Within or adjacent to a wetland
- On a slope greater than 3:1 (horizontal:vertical)
What TRCA Reviews
- Stormwater management plan
- Grading and drainage impact
- Erosion and sediment control
- Flood plain analysis (if applicable)
- Environmental impact on riparian zones
Timeline & Cost
- TRCA review: 2-4 weeks additional
- Application fee: $400-$1,200
- May require stormwater engineer report
- Submit before or concurrent with city permit
- Check TRCA mapping tool online first
How to Check If You Need TRCA Approval
Visit the TRCA's online Regulated Area Search tool and enter your property address. If your lot is flagged, contact TRCA Planning & Development directly before submitting your municipal permit. Your engineer should identify this requirement during the initial site assessment. DrySpace checks every project against TRCA maps as part of our standard permit coordination.
Required Documents for Drain & Sewer Permits
A complete application package avoids the back-and-forth that delays most permit submissions. Here is what Toronto Building and Toronto Water require for drain and sewer connection permits.
| Document | Description | Typical Cost |
|---|---|---|
| Plumbing Drawings | Detailed pipe layout showing sizes, materials, slopes, connections, cleanouts, and backwater valve location. Must be prepared or reviewed by a licensed plumber or BCIN designer. | $1,500-$2,500 |
| Site Grading Plan | Shows existing and proposed grades, drainage patterns, swales, downspout discharge points, and how stormwater is managed on site. Required when grading changes affect drainage. | $1,200-$2,000 |
| Flow Calculations | Engineering calculations showing pipe sizes are adequate for the expected flow rates. Based on fixture units (sanitary) or rainfall intensity (storm). | Included with drawings |
| Engineer Stamp (P.Eng) | Required for storm sewer connections and complex drainage designs. The engineer takes legal responsibility for the design. Not always required for simple backwater valve installs. | $500-$800 |
| Property Survey | Shows property boundaries, easements, setbacks, and existing service locations. Required for new connections to the city main. | $800-$1,200 |
| Camera Inspection Report | CCTV video inspection of existing drain lines to document current condition. Often required before city approves new connections to aging infrastructure. | $250-$500 |
Not Every Project Needs Every Document
A straightforward backwater valve installation may only need plumbing drawings and a permit application. A full storm sewer connection with grading changes will require the complete package. DrySpace determines exactly which documents your project needs during the free inspection, so you never pay for unnecessary engineering.
Drain Permit Cost Breakdown
Drain permit costs depend on the type of work. A simple backwater valve permit is on the low end, while a full storm sewer connection with grading approval is at the top of the range.
Permit Fees (City of Toronto)
Fees are calculated based on number of fixtures, pipe diameter, and connection type. Rates are set by the Toronto Municipal Code and updated annually.
Professional Services
Total Permit-Related Costs
$3,400 - $5,500
This range covers everything from a basic backwater valve permit to a full storm sewer connection with engineering. Many homeowners recover a large portion through the $3,400 City of Toronto rebate.
Inspection Stages for Drain & Sewer Work
Toronto Building requires three inspection stages for drain and sewer work. Each stage must pass before work can proceed. Inspections must be booked at least 48 hours in advance.
| Stage | What Is Inspected | When Required |
|---|---|---|
1 Pre-Burial Pipe Inspection | Pipe material, diameter, slope (minimum 2% for sanitary, 1% for storm), joint connections, cleanout locations, backwater valve placement, and bedding material | After pipes are laid in the trench but before any backfill. All pipes must be visible and accessible. |
2 Flow Test & Camera | Water flow test to confirm proper drainage, CCTV camera to verify no sags, offsets, or obstructions, and confirmation that backwater valve operates correctly | After Stage 1 passes. Inspector may perform the camera or accept a third-party camera report. |
3 Final Backfill & Grade | Proper backfill compaction, surface grading directs water away from foundation, downspout extensions in place, site restored per grading plan | After backfill is complete. This is the final sign-off that closes the permit. |
Never Backfill Before Inspection
The most common violation is burying pipes before the pre-burial inspection. If this happens, the inspector will require you to excavate and expose the pipes again at your own cost. This can add $2,000-$5,000 to your project.
DrySpace Inspection Management
We schedule all inspections, ensure work is ready before the inspector arrives, and handle any deficiency corrections immediately. Our pass rate on first inspection is over 95% because we build to code from day one.
Toronto Basement Flooding Protection Subsidy
Get Up to $3,400 Back
The City of Toronto Basement Flooding Protection Subsidy Program reimburses homeowners for installing flood-prevention devices. This is a rebate, not a loan. You pay upfront, complete the permitted work, and the city sends you a cheque.
$1,250
Backwater Valve Installation
$1,750
Sump Pump Installation
$400
Pipe Severance / Disconnection
Eligibility Requirements:
- • Property must be residential (single-family, semi, or townhouse)
- • All work must be done under a valid City of Toronto plumbing permit
- • Work must be performed by a licensed plumber or qualified contractor
- • Application must be submitted within 12 months of permit closure
- • Invoices, permit number, and inspection records required with application
DrySpace Handles Your Rebate Application
We prepare and submit the rebate paperwork on your behalf at no extra charge. We include all required documentation: permit number, inspection records, itemized invoices, and before/after photos. Most clients receive their rebate cheque within 6-8 weeks of submission.
Municipality Differences Across the GTA
While the Ontario Building Code is consistent, each municipality has its own utility department, fee structure, and application process for drain and sewer permits. Here are the key differences.
City of Toronto (Toronto Water)
Permit Authority:
Toronto Building (plumbing permit) + Toronto Water (sewer connection approval)
Application Portal:
eSERVICE online portal or in-person at Metro Hall, 55 John St
Flooding Rebate:
Up to $3,400 through the Basement Flooding Protection Subsidy
Special Notes:
Combined sewer areas require pipe severance; mandatory downspout disconnection city-wide
Region of Peel (Mississauga, Brampton, Caledon)
Permit Authority:
Local city building department (plumbing) + Region of Peel (sewer connections to regional mains)
Application Portal:
Varies: Mississauga Building Division, Brampton Building Services, or Caledon Building and Engineering
Flooding Rebate:
Mississauga offers a Backwater Valve Subsidy (up to $1,750); Brampton offers up to $2,800
Special Notes:
Credit Valley Conservation Authority (CVC) approval required near Credit River watershed
York Region (Vaughan, Markham, Richmond Hill)
Permit Authority:
Local city building department (plumbing) + York Region Environmental Services (regional connections)
Application Portal:
Each municipality has its own online building portal (Vaughan AMANDA, Markham ePlans)
Flooding Rebate:
Varies by municipality; Vaughan offers up to $2,800, Markham up to $2,000 for backwater valves
Special Notes:
TRCA regulated areas along Don River and Humber River; LSRCA for properties near Lake Simcoe watershed
Durham Region (Oshawa, Whitby, Ajax, Pickering)
Permit Authority:
Local building department (plumbing) + Durham Region Works Department (sewer connections)
Application Portal:
Municipality-specific: Oshawa Building Services, Whitby Building Division, etc.
Flooding Rebate:
Durham Region offers up to $2,750 through the Basement Flooding Prevention Subsidy Program
Special Notes:
Central Lake Ontario Conservation Authority (CLOCA) for properties near creeks and lakefront; generally faster permit turnaround than Toronto
Frequently Asked Questions
How much does a drain permit cost in Toronto?
Total drain permit costs range from $2,200 to $3,500 including engineering and application fees. The permit fee alone from Toronto Water is typically $1,200 to $2,000 depending on the scope. Additional costs include plumbing drawings ($1,500-$2,500) and site grading plans ($1,200-$2,000) if required. Simple backwater valve permits are at the low end; full storm sewer connections with grading are at the top.
Do I need a permit to install a backwater valve?
Yes, a plumbing permit is required for backwater valve installation in Toronto and all GTA municipalities. This is because the valve connects to the sanitary sewer system and must be installed to Ontario Building Code specifications. The good news: backwater valve installations are eligible for the City of Toronto's $3,400 Basement Flooding Protection Subsidy. DrySpace handles both the permit application and the rebate paperwork.
What is the difference between storm and sanitary sewers?
Storm sewers carry rainwater and snowmelt from roofs, driveways, and yards directly to rivers and Lake Ontario without treatment. Sanitary sewers carry household wastewater (toilets, sinks, showers) to treatment plants where it is cleaned before release. Toronto has combined sewer areas in older neighbourhoods where both types share one pipe. Connecting to the wrong system is illegal and will fail inspection. Your permit application must specify which system you are connecting to.
Do I need TRCA approval for drainage work?
Only if your property is within a TRCA regulated area, typically near ravines, rivers, creeks, wetlands, or flood plains. The TRCA regulates development in these zones to protect against flooding and erosion. You can check the TRCA's online Regulated Area Search tool by entering your address. If your property is flagged, TRCA review adds 2-4 weeks and $400-$1,200 in application fees to the permit timeline. DrySpace checks every project against TRCA maps as standard practice.
How long does a drain permit take?
With DrySpace managing the process, drain permits typically take 5-10 business days from submission to approval because we submit complete, code-compliant packages with all required documents. Applying through the city directly without professional guidance can take 4-8 weeks due to incomplete applications, revision requests, and longer processing queues. If TRCA approval is also needed, add 2-4 weeks to either timeline.
Can I connect my sump pump to the sewer?
No. In Toronto, sump pumps must never discharge into the sanitary sewer system. This is illegal under the City of Toronto Municipal Code Chapter 681 (Sewers). Sump pumps must discharge to the surface (grade) at least 1.2 metres from the foundation, or connect to the storm sewer if one is available and a permit is obtained. Connecting a sump pump to the sanitary sewer overloads the system during heavy rain and contributes to basement flooding in your neighbourhood. Violations can result in fines and mandatory disconnection.
What inspections are needed for drain work?
Drain and sewer work in Toronto requires three inspection stages: (1) Pre-burial pipe inspection where the inspector verifies pipe material, size, slope, and connections before anything is covered; (2) Flow test and camera inspection confirming proper drainage flow and no obstructions; and (3) Final backfill and grade inspection ensuring proper compaction, surface drainage, and site restoration. All inspections must be booked at least 48 hours in advance through Toronto Building's online portal.
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