Why you should install a backwater valve in Ottawa

In Ottawa, we’re lucky to have so much access to water and green space! There’s nothing better than kayaking down the Rideau River, biking the path beside the Rideau Canal or taking a boat tour down the Ottawa River. Unfortunately, this proximity to water also brings a unique set of challenges to homeowners living in Ottawa and surrounding areas such as Nepean, Barrhaven, Kanata, Orleans, Gloucester, and Vanier. 

Flooding and sewage backups are common issues facing Ottawa homeowners. In this blog post, we’ll delve into the solution to both of these issues: the backwater valve. We’ll walk you through what backwater valves are, how they work, how to maintain them and why every homeowner in Ottawa should seriously consider installing one (if they don’t already have one).


What is a backwater valve?

A backwater valve, also known as a back flow valve or a sewage backup valve, is a plumbing device designed to prevent the reverse flow of wastewater from the municipal sewer system into your home’s plumbing system. Backwater valves are particularly useful in areas prone to flooding, heavy rainfall, or sewage system backups such as Ottawa and surrounding regions. 

If you don’t have a backwater valve or it isn’t working correctly you run the risk of sewage entering your home through floor drains in the basement or through sinks, bathtubs, toilets and other fixtures.

How does a backwater valve work?

Backwater valves operate using a simple but effective mechanism:

  • The backwater valve is installed in the main sewer line beneath your home. This is the line where all the wastewater from your sinks, toilets, bathtubs and other fixtures is mixed together and travels out to the municipal sewer system. 
  • Inside the valve is a hinged flap. Under normal conditions, the flap remains in an open position, allowing wastewater to flow from your home into the sewer system
  • When water or sewage attempts to flow backward, the flap is forced closed by the pressure of the incoming wastewater. This action effectively seals off your home’s plumbing system!

It’s important to remember that while the flap is closed wastewater is also unable to leave your home’s plumbing system. Making it important to refrain from running water or using the fixtures in your home during this time.

How do I know if my house has a backwater valve? Do all homes have a backwater valve?

Not all homes have backwater valves as their installation varies based on local regulations, building codes, and the home’s age. In Ottawa, backwater valves have been required in all new single-family homes, duplexes, row houses, and townhouses since 2004, however many homes had them installed even before that. If you live elsewhere in Canada your municipality will have its own regulations, however, the National Plumbing Code mandates the installation of backwater valves in new homes that have basements since they have a higher chance of water backing up. 

To find out if your home has a backwater valve inspect your basement for a valve like the one pictured below. They are also sometimes installed in the front or backyard depending on the location of the main sewer line under your home. Alternatively, you can always consult your building records or home inspection report, or seek guidance from a licensed plumber for a professional assessment. 

Pro Tip

If you install a new backwater valve make sure to give your insurance company a call and update them. You can often get a lower premium from installing protective plumbing equipment.

Do backwater valves need maintenance? How do you maintain a backwater valve?

Maintenance is crucial for a backwater valve because it ensures the device’s continued effectiveness in preventing sewage backups and water damage. Over time, debris, sediment, and waste materials can accumulate within the valve and stop it from functioning properly. That’s why routine upkeep of a backwater valve is essential to ensure that it functions reliably and provides continuous protection to your home against sewage backups and related problems. 

One of our experts can efficiently perform this essential maintenance for you, offering peace of mind and safeguarding your property. Learn more about plumbing maintenance.

Are there Ottawa backwater valve rebates or subsidies?

Many homeowners in Ottawa, Nepean, Barrhaven, Kanata, Orleans, Gloucester, and Vanier have unfortunately faced the distressing situation of city sewage or flood water backing up into their basements, resulting in significant home damage and the arduous task of cleanup. 

What many homeowners in the Ottawa region may not be aware of is that the city has three programs designed to help homeowners with flooding and sewage backup issues: the Residential Protective Plumbing Program, the Preventative Maintenance Program and the Residential Compassionate Grant

The Residential Protective Plumbing Program (RPPP) can cover anywhere from 50% to 100% of the expenses associated with the installation of a new protective plumbing device such as a backwater valve and/or a sump pump. This rebate does not cover any repairs, maintenance and replacement of a current protective plumbing device, however, is a great option for Ottawa homes that lack this infrastructure. For more information on eligibility and how to apply, visit the City of Ottawa website

The Preventative Maintenance Program applies to Ottawa properties that have experienced a sewer backup caused by trees owned by the City of Ottawa or structural defects on the City-owned portion of the sewer. The City of Ottawa offers a sewer maintenance service annually to these impacted properties to ensure the proper function of the sewer and help prevent sewer backups. – Learn more

The Residential Compassionate Grant is designed to assist homeowners who have recurring issues with sewage backup in their homes. Ottawa homeowners who have been affected by flooding three or more times in the past 15 years could be eligible for a grant of up to $1,000. – Learn more 

Interested in a backwater valve installation in Ottawa or surrounding regions? Contact Francis Plumbing Heating & Cooling, your Ottawa backwater valve experts!

Backwater Valve FAQs

Why do I hear an alarm near the backwater valve?

An alarm may be added to a backwater valve to alert you that the valve has been engaged and is restricting flow back toward your basement. When you hear the alarm and when you see that the valve is engaged, it means that the backwater valve is working as it should. Do not shower, flush toilets or wash clothing until the system has returned to routine functioning, as additional water will not flow out of the residence when the valve is engaged. You can resume routine use when the alarm and the backwater valve are no longer engaged.

Need backwater valve maintenance in Ottawa or surrounding areas? Contact Francis Plumbing Heating & Cooling, your Ottawa backwater valve experts!

Are backwater valves a good idea?

Yes, backwater valves are a good idea for homeowners, especially in areas prone to sewage backups or flooding, such as Ottawa. Installing a backwater valve safeguards your home, can prevent damage, and provides peace of mind in the face of potential sewer system issues.

Interested in a backwater valve installation in Ottawa or surrounding regions? Contact Francis Plumbing Heating & Cooling, your Ottawa backwater valve experts!

How long do backwater valves last?

The lifespan of a backwater valve will vary depending on factors like its quality, maintenance frequency, and usage. However, with proper care and maintenance backwater valves can last essentially forever.

Need backwater valve maintenance in Ottawa or surrounding areas? Contact Francis Plumbing Heating & Cooling, your Ottawa backwater valve experts!

Where is the backwater valve located?

A backwater valve is located on the main sewer line of a building, this typically means it is below the concrete foundation of your home. It can be accessed most commonly from the basement though sometimes they are placed in the front or back yard of a home.

Not sure if your home has a backwater valve? Don’t worry! Our plumbing experts can help locate and maintain this system for you. Contact Francis Plumbing Heating & Cooling today, your Ottawa backwater valve specialists!

Do I need a sump pump if I have a backwater valve?

Sump pumps and backwater valves address two different issues. A backwater valve prevents sewage or wastewater from flowing back into your property during sewer system issues, but it doesn’t address groundwater or rainwater infiltration. If your area is prone to heavy rainfall or flooding, a sump pump may be necessary to manage excess groundwater, ensuring that it doesn’t accumulate in your basement. 

Some Ottawa homeowners choose to install both a backwater valve and a sump pump to provide comprehensive protection against sewage backups as well as groundwater issues. Consulting with a professional plumber will help you determine the best solution for your property.

How much does a backwater valve cost in Canada?

If installed when the home is being built backwater valves are relatively inexpensive, however, retrofit backwater valve installations are much more expensive and can cost between $3,500 and $5,500. This is because of the significant amount of labour required to safely break through the home’s foundation. It is important to remember that even a single sewage backup event can cost thousands in repairs and damages. Additionally, the City of Ottawa’s Residential Protective Plumbing Program can help cover a significant portion of the cost if your home qualifies. – Learn more

What is the difference between back flow and backwater valves?

Backwater valves are also sometimes called sewer backup valves or back flow valves – they all refer to the same piece of equipment. 

Interested in a backwater valve installation in Ottawa or surrounding regions? Contact Francis Plumbing Heating & Cooling, your Ottawa backwater valve experts!

Are there any municipal or provincial subsidies for backwater valves?

The City of Ottawa offers backwater valve rebates to qualifying homeowners through the Residential Protective Plumbing Program. The rebate covers a significant portion of the cost of various protective plumbing devices including backwater valves (sewer backup valve/back flow valves) and sump pumps. – Learn more about the backwater valve rebate