Every spring and summer, Edmonton homeowners deal with the same risk: heavy rainfall overwhelming the city’s sewer system and sending raw sewage back toward your home. A backwater valve is one of the most effective tools you can install to stop that from happening, and if you live in an older home, there is a good chance you do not have one.
This guide covers what a backwater valve is, how it works, how to check if your home already has one, what installation involves, and how to take advantage of EPCOR’s rebate program.
What Is a Backwater Valve?
A backwater valve, also called a backflow valve, sewer backflow preventer, or sewer backup valve, is a one-way valve installed on your home’s main sewer line. Its job is simple: it allows waste to flow out of your home into the municipal sewer system, but automatically closes if flow starts moving in the wrong direction.
During periods of heavy rainfall or flash flooding, Edmonton’s sewer lines can become overwhelmed. When that happens, sewage has nowhere to go but back the way it came. Without a backwater valve, that means raw sewage can back up through your floor drains, toilets, showers, and bathtubs.
With a backwater valve installed, the flapper inside the valve automatically closes the moment backflow is detected, blocking sewage from entering your home entirely.
Does Your Edmonton Home Have One?
If your home was built after 1989, there is a reasonable chance a backwater valve was installed during construction. Homes built before 1989 were not required to have one, so if you own an older property, it is worth checking.
Here is how to check:
Head to your basement, or garage if that is where your plumbing runs.
Look for a round or rectangular access box in the floor near your main drain line or sump pump area.
If you find one, remove the cover temporarily and familiarize yourself with the valve and flapper inside.
If you are not sure what you are looking at, an Always Plumbing technician can inspect it during any service visit.
How to Maintain Your Backwater Valve
A backwater valve requires minimal maintenance, but ignoring it entirely is not a good idea, especially heading into storm season.
Every couple of months, inspect the flapper inside the valve to check for buildup or debris. To clean it, wear gloves, goggles, and old clothes. Clear any buildup from the flapper so it can open and close freely.
If you notice the valve leaking during a routine check, it likely needs to be replaced rather than repaired. Contact Always Plumbing to have a technician assess it.
Backwater Valve Installation in Edmonton
If your home does not have a backwater valve, installation is straightforward for a licensed plumber. In Edmonton and surrounding areas, a permit is required for backwater valve installation. Always Plumbing handles the permitting process as part of every installation, so you do not need to navigate that on your own.
Our technicians arrive in fully stocked service trucks, inspect your foundation and plumbing to determine the best placement, and explain all recommendations before any work begins. Pricing is provided upfront with no hidden fees.
The EPCOR Backwater Valve Subsidy
EPCOR offers a backwater valve subsidy program for eligible Edmonton homeowners that can cover up to $800 toward the cost of an approved valve and accredited installation.
You may qualify if:
Your home was built before 1989
You have previously experienced flooding from stormwater or sewer backup
You are a proactive homeowner in a higher-risk area (eligibility is assessed on a case-by-case basis)
The process works like this: book a pre-approval inspection directly with EPCOR using their online booking system or by calling 780-944-7777, get approved, then call Always Plumbing to complete the installation within six months of your inspection date. After installation, submit your application to EPCOR within that same six-month window. Your application must include a professional installation invoice showing the valve model, and a copy of the City of Edmonton green sticker with the permit number. The subsidy is paid by cheque to the homeowner. Note that funding is provided on a first-come, first-served basis and is subject to availability, so there is no guarantee of approval even if you meet the eligibility requirements.
EPCOR Program: Verified Current as of June 2026 The $800 cap, pre-approval requirement, and EPCOR contact details have been verified against EPCOR’s current program page (epcor.com) as of June 2026. The program remains active. The six-month install and application window, first-come first-served funding note, and green sticker permit requirement have been added to this version based on current program documentation. Always recommend the client link directly to EPCOR’s Backwater Valve Subsidy page for the most current approved valve list and funding availability. |
Pairing a Backwater Valve With a Sump Pump
For maximum basement flood protection, many Edmonton homeowners install a backwater valve alongside a sump pump. The two systems work together: the sump pump handles groundwater and surface water that enters the basement, while the backwater valve blocks sewage from backing up through your drains.
If you are already investing in one, it is worth asking about both. Always Plumbing installs and services both systems across Edmonton and the surrounding areas including Sherwood Park, St. Albert, Spruce Grove, Stony Plain, Leduc, and Beaumont.
Ready to Protect Your Home?
If you are unsure whether your home has a backwater valve, or if you know you need one installed, Always Plumbing is here to help. Call us at (587) 742-1359 or fill out our online form to book an inspection or get a no-obligation quote.