How a backwater valve protects your basement
Edmonton's older neighbourhoods were built with sewer systems that can surcharge in heavy rain. When the city sewer fills faster than it drains, sewage takes the path of least resistance, which is up through your basement floor drain. A backwater valve is a one-way valve installed on your main sewer line. Normally it stays open so your house drains freely; when sewage starts flowing backwards, a flap closes and seals it out.
After the major Edmonton storms of 2004 and 2012, thousands of basements flooded with sewage. A properly installed and maintained backwater valve is the single most effective protection against that.
EPCOR's backwater valve subsidy
EPCOR offers a subsidy of up to $800 toward installing a backwater valve. As of 2026, eligible homes generally must:
- Be in Edmonton and built before 1989.
- Be separately serviced (a single-family home or a duplex).
- Not already have a backwater valve, or have received the subsidy before.
- Have had a previous sewer backup, or be in a neighbourhood with a history of flooding.
You'll need the City of Edmonton green inspection sticker with permit number, a paid invoice showing the valve model and the plumber's business licence or GST number, and EPCOR's application form. Funding is first-come, first-served and not guaranteed, so it's worth applying soon after installation. Our subsidy guide walks through every step.
Program details can change. Always confirm current terms with EPCOR before you rely on the subsidy.
What the installation involves
- Assessment: we locate the main sewer line, camera it to check its condition, and confirm the valve won't cause problems with other fixtures or a sump pump.
- Permit: we pull the City of Edmonton plumbing permit.
- Install: we cut the concrete floor (usually near the front wall), excavate to the pipe, and install the valve with an accessible lid for maintenance.
- Inspection: a City inspector checks the work and issues the green sticker before the floor is closed.
- Restore: we backfill and pour new concrete, leaving the access lid flush with the floor.
Most installs are done in one day, plus the inspection. Finished basements are no problem; we plan the location to minimize disruption to flooring and walls.
Keep it maintained
A backwater valve needs a quick check at least once a year (we recommend spring, before storm season) to make sure the flap moves freely and nothing has lodged in it. We'll show you how at install, or you can book an annual check with us.