Thinking about a backwater valve and wondering what it will really cost you? The price on the invoice and the price you end up paying are two different numbers, because Toronto, Peel Region and Halton Region all help pay for the valve.
We install backwater valves across the GTA and show your expected rebate on every estimate. Here is how the numbers work.
The average cost of a backwater valve
In a 2025 staff report, the City of Toronto reported an average backwater valve installation cost of about $3,800. That covers breaking the basement floor, installing the valve in the main drain, the access cover, concrete repair, the permit and the inspection.
Your price can be higher or lower. The depth of the drain, finished flooring, the condition of the sewer line and whether you need two valves all make a difference.
What the rebate pays where you live
Toronto. The City pays 80% of the eligible invoice, up to $1,600 per valve. On a $3,800 invoice, that is $1,600 back, leaving you with $2,200.
Peel Region (Mississauga). The Region pays 60% of a sanitary backwater valve, up to $1,500 including tax. On a $3,800 invoice, that is $1,500 back, leaving $2,300.
Halton Region (Oakville, Burlington, Milton). The Region pays 50% up to $1,600. On a $3,800 invoice, that is $1,600 back, leaving $2,200. In Burlington, the City also covers the permit fee for sanitary line work that includes a backwater valve.
What the rebate requires
Every program needs an itemized invoice from a licensed contractor, and backwater valves need a plumbing permit and passed inspection. Toronto also requires your downspouts to be disconnected, or an exemption granted. We handle the permit, book the inspection and prepare the documents.
Do you need anything else?
If your weeping tiles drain into the sewer line, a backwater valve can trap foundation water while it is closed. In that case, a sump pump is often recommended alongside the valve, and Toronto pays 80% of eligible sump pump costs up to $2,250.
See your own numbers
Use our rebate calculator to estimate what your municipality pays, then book a free estimate. We will quote the work and show your rebate and your cost after it, in writing.
