Toronto Backwater Valve Rebate — Up to $3,200
Last reviewed: April 30, 2026 · Source: City of Toronto
Quick answer
Toronto offers up to $1,600 per backwater valve, with a maximum of 2 devices per property ($3,200 total). Subsidy covers 80% of cost. Permit and City inspection required.
What a backwater valve does
A backwater valve is a device installed in your home's plumbing that allows wastewater to flow out but blocks reverse flow from the municipal sewer during heavy rain or sewer surcharge events.
When the City sewer becomes overloaded — which happens during severe rainfall — wastewater can back up through floor drains, toilets, or basement plumbing. A backwater valve closes automatically when reverse flow is detected, preventing sewage backup into your home.
Important
When a backwater valve is activated during a flood event, you cannot use plumbing fixtures (toilets, sinks, washing machine) — drainage may not flow to the sewer and could back up internally.
Subsidy details
| Per-device cap | $1,600 |
| Maximum devices | 2 per property |
| Subsidy rate | 80% of invoiced cost |
| Maximum total | $3,200 |
Why 2 devices? When you might qualify for both
The City allows the subsidy for up to 2 backwater valves on properties with multiple sewer connections. This is most common in:
- •Older homes with separate connections for sanitary and storm sewers
- •Duplexes, triplexes, or fourplexes with multiple sewer entries
- •Properties with separate basement and main floor drainage
Required documentation
Calculate your potential subsidy
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Start calculator →Common questions
How much is the Toronto backwater valve subsidy?
The City of Toronto offers up to $1,600 per backwater valve, with a maximum of 2 devices per property — totalling up to $3,200. The subsidy covers 80% of the invoiced cost, capped at $1,600 per device.
Do I need a permit for a backwater valve installation?
Yes. Backwater valve installation requires a building permit from Toronto Building and an inspection by Toronto Building staff. Your contractor should handle the permit application as part of the installation.
How does a backwater valve work?
A backwater valve allows water to flow out of your home but blocks reverse flow from the municipal sewer during heavy rain or sewer surcharge events. When activated, you cannot use plumbing fixtures because drainage may not flow to the sewer.
Can I install a backwater valve myself?
No. The work must be done by a contractor with a valid City of Toronto business licence to qualify for the subsidy. Self-installation does not qualify.
Related guides
SOURCE & DISCLAIMER
Information based on the City of Toronto Basement Flooding Protection Subsidy Program (BFPSP). Last verified: April 30, 2026.
ClaimRebate.ca is an independent homeowner guide. We are not affiliated with the City of Toronto. Final eligibility and subsidy amounts are determined by the program administrator.