Basement flooding is on the rise in Toronto. Every home is at risk of basement flooding, even if it has not happened before. Water in your basement is most likely to occur during a heavy rainfall, or when snow and ice is melting, but you can take steps to help reduce or prevent it from happening.
A backwater valve, also called a backflow valve, is a device used to prevent outbound water in a home’s drain pipes from re-entering, or “backflowing”—into your home. The valve has a flap that allows water to leave but closes to prevent water and/or sewage from entering.
Backwater valves are designed to close the sewer line during periods of extreme rain to prevent water from entering your home. When the valve is closed you should not use any plumbing fixtures (i.e. toilets, sinks, dishwashers, washing machines) because water will not drain and will back up into your home.
What to Look For
- The Insurance Bureau of Canada recommends residents not install the plug-type valves, as they allow sewer backup pressure to build beneath your basement floor, which may cause structural damage to your home.
Things to Consider
- Toronto residents need a standalone drain permit to install a backwater valve in any home with one or two dwelling units.
- Hire a licensed plumber to install your mainline backwater valve.
- Check and clean your backwater valve once a year, preferably in the early spring before the snow melts.
- Take other measures around your home to prevent basement flooding, including installing a sump pump.
- Let your home insurer know if you install a backwater valve, as it reduces your home’s risk of flooding.
- Apply to the City of Toronto’s Basement Flooding Protection Subsidy Program to offset some of the installation costs.
- Tenants, to understand your rights after a flood, contact the Federation of Metro Tenants’ Associations’ tenant hotline at 416-921-9494.
$500 to $2,000 including installation.
Source: Insurance Bureau of Canada