Homeowner library · Flooding
What to do when the basement floods
A flooded basement is stressful, but a clear sequence of steps protects your safety, limits damage and helps with insurance.
- Plain steps you can check yourself
- When it is safe to try and when to stop
- What a plumber does next
- One phone call if you want it handled
- Licensed, insured trade work (details confirmed when you call)
- Diagnosis before anything is cut
- Emergency calls taken
- Etobicoke and the west end
Safety first
Stay out of the water if any plug, extension cord or appliance are submerged or the panel is nearby. If you cannot safely reach the breaker, call your electric utility. Sewage water carries bacteria; wear boots and gloves.
- Gas appliances that were flooded need inspection before use.
Find the source
Clean water from a burst pipe: shut the main valve. Sewage at the grate: quit using the taps and toilets upstairs; it is likely a blocked main or city sewer surcharge. Groundwater at the walls: check the sump pump.
- If the city sewer is backing up, call 311 to report it.
Document and clean
Photograph everything before moving it. Contact your insurer early. Remove water and wet materials quickly to limit mould. After the emergency, plan protection: backwater valve, sump pump, downspout disconnection.
- Toronto has offered a subsidy program for some protective plumbing; check current terms.
After the water is gone
Dry the space quickly with fans and dehumidifiers. Remove wet carpet, underpad and drywall that cannot dry within a day or two. Clean and disinfect surfaces touched by sewage. Check the furnace and water heater for water damage.
- Ask your plumber what caused the flood and what can prevent it next time.
Insurance and records
Keep receipts, photos and the plumber’s report. Many policies treat sewer backup differently from groundwater; check your coverage.
The first hour
Stay safe
Avoid water near electricity.
Stop the source
Main valve or stop using drains.
Call
Plumber, insurer, and 311 if city sewer.
Document
Photos before cleanup.