What to do when your basement floods

By TransparentBuilders · Updated September 2026

First, stay safe

If water is near outlets, appliances or the electrical panel, don't go into the basement. Call your electric utility or an electrician to cut the power safely. If you smell gas, leave the house and call your gas utility or 911 from outside.

Then, step by step

1. Stop the water if you safely can. For a burst pipe or leak, shut the main water valve, usually near where the water line enters the basement.
2. Don't flush or run water if the water came up through a floor drain. It may be a sewer backup, and using water upstairs can make it worse.
3. Take photos and video of the water, the damage and your belongings before you move anything.
4. Call your insurance company and get a claim number. Ask whether your policy includes sewer backup and overland flood coverage.
5. Call a restoration company. Drying should start as soon as possible, ideally within a day, before mould has a chance to grow.
6. Move dry belongings upstairs, and lift furniture off wet floors if it's safe to go down.
7. Keep receipts for anything you buy or any place you stay because of the flood.
8. Report it to your city if you think the sewer backed up. Many GTA cities track basement flooding and some offer programs after major storms.

What not to do

• Don’t use a household vacuum to pick up water.
• Don’t touch sewage water without gloves and boots.
• Don’t throw out damaged items before your adjuster has seen them or you’ve photographed them.
• Don’t close up wet walls. Anything wet that gets covered can grow mould.

After the cleanup

Once the basement is dry, it's the best time to stop it happening again. A backwater valve, a sump pump with battery backup and disconnected downspouts protect most homes, and many GTA cities pay part of the cost.

Basement flooding rebates by city · Flooded basement cleanup