Homeowner library · Flooding
Basement flooding protection in Toronto
Several measures work together to keep water out of a basement. Here is how each one helps, and what to know before installing them in Toronto.
- Backwater valve: Permit required
- Sump pump: May require permit with pipe changes
- Downspouts: Direct away from foundation
- City program: Check current terms
- Licensed, insured trade work (details confirmed when you call)
- Diagnosis before anything is cut
- Emergency calls taken
- Etobicoke and the west end
Protection at a glance
- Backwater valve
- Permit required
- Sump pump
- May require permit with pipe changes
- Downspouts
- Direct away from foundation
- City program
- Check current terms
Backwater valve
Stops sewage from the city sewer flowing back into your home during surcharge. Installed in the main drain inside the basement, with a permit.
- Must be maintained and used with care during storms.
Sump pump
Collects water from foundation drains and pumps it outside. Often paired with disconnecting foundation drains from the sanitary sewer.
- Battery backup helps during outages.
Downspouts and grading
Disconnecting downspouts from the sewer and directing water away from the foundation reduces load. Grading the soil to slope away helps too.
- The City of Toronto has funded part of this work through a flood-protection subsidy; confirm the current eligibility and requirements before starting work.
How the pieces fit together
A backwater valve protects against sewer surcharge but blocks your drains while closed. A sump pump handles groundwater from foundation drains. Disconnecting downspouts and foundation drains from the sewer reduces both the load on the city system and the chance of backup. Together they give layered protection.
- Not every home needs every measure; it depends on how your plumbing and drainage are connected.
Getting started
Begin with a camera inspection of your main drain to see its route and condition.
- Then decide on valve placement, sump requirements and permits.
- Check city program requirements early, as some require specific steps before work begins.
Maintenance
Inspect the backwater valve flap periodically and keep the access cover clear.
- Test the sump pump each spring.
- Keep downspout extensions in place.