Stop Sewer Backup Before It Reaches Your Basement
A backwater valve stops sewer backup before it reaches your basement. The City of Toronto offsets a significant portion of installation costs through the Basement Flooding Protection Subsidy.

Why Sewer Backups Happen — and What They Actually Cost Toronto Homeowners
Sewer Backup

When heavy rain fills the system, sewage reverses direction and enters basements through floor drains. Cleanup for finished spaces regularly exceeds $50,000. Sewage exposure creates serious health risks, and insurance may not cover the damage if no backwater valve is installed. Homes near ravines, Lake Ontario, and the Don Valley face elevated risk — but any property on the combined system is vulnerable as storm intensity increases.
How a Backwater Valve Prevents Sewer Backup


Toronto's Backwater Valve Rebate — Eligibility and the Full Process
The City of Toronto Basement Flooding Protection Subsidy reimburses homeowners up to 80% of invoiced installation costs. Here is what the program covers, what the installation involves, and what Rainbow Drains handles for you.
- Rebate covers up to 80% of cost
- Single-family through fourplex
- City-licensed plumber required
Rebate Eligibility
- Permit obtained before work begins
- One to two day installation
- City inspection confirms code compliance
Installation Process
How Backwater Valve Protection Fits Into a Bigger System
Worth Knowing
A backwater valve addresses one specific threat — sewer backup from above. But basement flooding has more than one cause, and Toronto's rebate program covers more than one solution. Understanding the connections helps you plan complete protection.
From First Call to Rebate Cheque
Questions Homeowners Ask Before Booking
Honest answers about this service and what the process actually involves.
Contact UsHow do I know if my home qualifies for the rebate?
If you own a residential property in Toronto — a single-family home, duplex, triplex, or fourplex — you almost certainly qualify. The key requirements are that the installation is performed by a City-licensed plumber, a building permit is obtained beforehand, and the installation passes a City inspection. We confirm eligibility during the assessment.
What factors affect the total cost of installation?
The main variables are the location and depth of your main drain line, the type of basement floor (concrete thickness, obstacles), and whether any existing plumbing needs to be rerouted. Access conditions and the complexity of the excavation also play a role. The quote you receive accounts for all of these — no cost surprises after the assessment.
How long does the full process take from first call to rebate cheque?
The assessment happens within days of your call. Installation typically takes one to two days. City inspection scheduling depends on the City’s availability but usually occurs within one to two weeks. The rebate application can be submitted immediately after inspection. The City’s processing time for the cheque varies but is typically a few months.
What if I already have a backwater valve that is old or not working?
Replacement of an existing valve is eligible for the same rebate. If your current valve is outdated, damaged, or was installed without a permit, a new permitted installation qualifies. The assessment will determine the condition of your current setup and whether replacement is warranted.
Can a backwater valve cause problems with my regular drainage?
A properly installed valve does not affect normal drain function. The flap stays open during everyday use and only closes when backup pressure is detected. The only time drainage is affected is during an active sewer backup event — which is exactly when you want the valve sealed shut.
You Understand the Program. Let Us See If Your Home Qualifies.
The next step is a home assessment — we confirm eligibility, inspect your drain system, and provide a clear quote with the rebate math included.
- Licensed & Insured Professionals
- 24/7 Emergency Response Available
- Clear Pricing — No Hidden Fees
- No-Obligation Assessment
- 15+ Years Experience in the GTA
Or call us directly at (416) 807-6713






