Toronto Backwater Valve Installation & Backflow Prevention

Backwater Valve Installation & Benefits – Toronto RES Plumbing

Is your Toronto property located in a high-flood-risk area? Even if it is, you might not know due to poor municipal management of local flood maps. There is good news, though. This being that a backwater valve installation can prevent basement flooding in even high-risk flood zones. Benefit from better peace of mind by calling RES Plumbing now to find out more.


Every Home Needs a Backwater Valve

On August 7th, 2018, 72 mm of rain fell on Toronto in just 2-hours. With 51 mm of rain falling in a single hour, property owners have since filed claims with insurers for over $80 million in property damage. However, just like with the great Toronto flood of 2013, a simple backwater valve installation could have helped eliminate flooding risks in most areas.

Not to be confused with backflow preventer systems, backwater valves prevent excess water in mains sewer lines from backing up into properties during periods of heavy rainfall.

Sump Pump Installation Everett Wa

What is a Backwater Valve Installation?

During periods of heavy rainfall, sewers and drains can struggle to cope with rapidly increasing volumes of water. In Toronto, this results in sewer water backing up into individual property sewer lines. When this happens, wastewater can back up into property drains and basements.

At it’s most basic, a backwater valve is a shutoff device. Usually installed in a property basement, backwater valves seal property sewer lines from mainline sewer systems as water starts to backup. This prevents basement flooding. More importantly, valves will automatically release when backups have cleared.

Backflow Prevention Device Installation 600x400

Backwater Valves Vs. Backflow Preventers

In Toronto, it is common to hear backwater valves referred to as backflow preventer systems. However, a backflow preventer system will not protect a property from flooding.

  • Backwater valves are wholly different from backflow preventer systems

  • Backflow prevention devices prevent reverse flow of solids, liquids, and gasses into fresh (potable) water systems

  • Only a backwater valve will prevent sewer water from backing up into property drains during heavy rainfall

  • Backflow preventer systems do not prevent basement flooding. This is critical to remember when hearing terms like ‘backwater’ and ‘backflow’ used interchangeably


Backflow prevention devices are commonplace in Toronto. However, not knowing the difference between a backflow system and a true backwater valve installation can be costly. Even when a backflow preventer system is installed at the advice of property insurers, flooding risks will always remain. This being the case, when looking to eliminate basement flooding for good, always reach out to plumbers like ourselves who differentiate between the terms ‘backflow’ and ‘backwater.’

Why Trust RES Plumbing with Your Backwater Valve Installation?

RES Plumbing provide commercial and residential plumbing services all across Toronto. Unlike other local plumbers, we never install ineffective backflow preventer systems in place of true backwater valves. We also only start work after thoroughly mapping home and business drainage systems. This way, we maximize property flooding protection, by identifying the most effective site for any new backwater valve.

Extensive mold growth on the sheetrock drywall ceiling anjd walls of a property

Backwater Valve Installation Benefits

A backwater valve is the most effective way for businesses and homeowners in Toronto to prevent basement flooding. At present, backwater valves are not mandated by municipal officials. However, installing a backwater valve can add value to properties, as well as eliminate future flooding concerns.

  • A backwater valve installation can add market value to Toronto properties, especially in areas prone to flooding

  • Backwater valves prevent damage to basement sump pump systems during sewer backups

  • When installed by licensed plumbers like ourselves, backwater valves can lower property insurance premiums

Extensive mold growth on the sheetrock drywall ceiling anjd walls of a property
Feat Emergency Plumbing Services

Other Benefits

While a backwater valve can eliminate the threat of basement flooding, valves can also prove useful on a day to day basis.

Tree roots and debris in property sewer lines can cause basement flooding and sewer backups, even in the absence of heavy rainfall. In such cases, a backwater valve will keep a basement dry until backup causes are properly investigated.


How Does a Backwater Valve Work?

Home and business sewer lines in Toronto, are gravity based. Wastewater, therefore, flows downhill to reach mainline sewer systems.

At their most basic, backwater valves utilize a flap-based system which is pushed close by water rising through a property sewer line. Doing so creates a seal which becomes tighter as outside water pressure increases. No wastewater can, therefore, rise through sewer lines, even during periods of heavy rainfall.

Automatic backwater valves are 100% effective in most home and business contexts. However, manual systems also exist. These require property owners to manually crank a lift gate into place which separates sewer lines from mainline sewer systems. In most cases, manual installations are more heavy-duty and used only in commercial and industrial contexts, not residential areas.

Backwater Plumbing Valve

The Backwater Valve Installation Process

In Toronto, backwater valve installations are not mandated by law. (However, this may change in future.) For this reason, property owners are required to apply for a permit before installation.

At RES Plumbing, we can help submit permit applications. Once permits have been issued, we will identify the best location for your backwater valve and set to work accordingly. Usually, the installation will take a couple of days and necessitate cleaning and mapping of different drainage outlets. However, during the installation process, you will be able to utilize your home plumbing without restriction.

Say Goodbye to Home & Business Flooding For Good

Storm surges and flooding in Toronto is on the increase. If you live in a low lying area, it is, therefore, likely only a matter of time before flooding affects you directly.

Don’t wait to get caught out by suddenly rising water levels. Protect your home, your family, and your finances, by reaching out today for a free, no-obligation initial backwater valve consultation.