What Is a Backwater Valve?

A backwater valve is a one-way gate on your sewer lateral. City water can't push back into your basement when the municipal sewer overloads.

Common causes

• Heavy rain overwhelming municipal sewers
• Combined storm/sanitary sewers backing up
• Older homes on clay laterals
• No mechanical prevention on the outgoing sewer

Step-by-step

1. 01Locate the sanitary sewer lateral (usually in the basement floor)
2. 02Camera-inspect the line for structural issues before install
3. 03Cut in a code-compliant valve with an accessible chamber cover
4. 04Register for the City of Toronto subsidy — up to $3,400 available

When to call Northbridge

• You've had any basement backup in the past
• Home is in an older Etobicoke neighbourhood
• You want subsidy paperwork handled
• Renovation is a good time to add one