Backwater Valve Installation in North York

What a backwater valve does

During an intense storm, municipal sewers can fill faster than they drain. Then water hunts for the lowest way out, which in a lot of houses means the floor drain downstairs. A mainline backwater valve sits in the sewer pipe under the basement floor. A hinged flap stays open for normal flow and swings shut when water tries to move the wrong way.

• Basements that have flooded through the floor drain before
• Homes on low-lying streets or near ravines
• Finished basements with valuable contents
• Houses on streets with combined or older sewers

How installation works

1. We camera the line to find the right spot and check pipe condition.
2. A section of basement floor is cut and the pipe is exposed.
3. The valve is installed in line with an access cover at floor level.
4. Any fixtures that must drain while the valve is closed are planned for.
5. The work is inspected where a permit is required, and the floor is restored.

Toronto context

Toronto's basement flood subsidy has in past years paid part of the cost of a backwater valve, sump pump and pipe severance for eligible homes. Requirements, paperwork and amounts change over time. Check the city’s current terms before work starts, as some programs require specific steps in a specific order. Our subsidy guide explains the general process.

Looking after the valve

Lift the access lid each spring and fall to confirm the flap swings easily with no debris lodged in it. Our guide on how a backwater valve works walks through that check. Pairing the valve with a sump pump covers groundwater as well as sewer surges.