The first six hours after a basement flood

Hour one: make it safe, then stop the water

Do not go down to switch the power off yourself. ESA, Ontario's Electrical Safety Authority, says not to enter a basement if the water is above the level of electrical outlets, baseboard heaters or furnace, or is near the electrical panel, and to call the local electric utility to disconnect power to the home. The Government of Canada says not to attempt to shut off electricity if any water is present. Standing water touching a live outlet or an appliance cord is the one hazard in this whole sequence that can kill you, and it is the reason the order starts here rather than with a phone call.

Then find the source and stop it. A burst supply line means the main shut-off. A failed sump means the pump. Surface water coming in from outside will keep coming until the rain stops, which changes what is worth doing now. Extraction before the source is closed is work that has to be redone, and drying cannot finish while water is still arriving.

Hour two: photograph it before anything moves

Take more photographs than feels sensible, and take them before you move a single box. Wide shots of each room, the water line on the walls, the source itself, the serial plates on anything mechanical, and close-ups of every damaged item. Video with the phone talking through it is better still.

This is the single highest-value ten minutes in the whole process, because an insurance claim is settled on what you can demonstrate. Once a crew has extracted the water and carted out the drywall, the evidence of how bad it was leaves with them.

Sewage is the exception to the urge to tidy up. Category 3 black water carries bacteria and pathogens, so it is a biohazard, and the right move is to keep people and pets out and let a crew with proper protective equipment and containment handle it rather than mopping.

Hour three: call your insurer before you agree to any work

Open the claim before a contractor starts, because Ontario coverage for water is narrower than most homeowners expect and what you are covered for changes what you should authorise.

Sudden, accidental water such as a burst pipe is usually covered by a standard policy. Sewer backup is not: it needs a separate endorsement, which Ratehub puts at roughly $150 to $300 a year and as high as $700 in an area with a high frequency of claims, and Ratehub recommends carrying at least $100,000 of it against typical claims of $2,000 to $10,000. Overland water, meaning surface flooding entering above grade in heavy rain, is a different endorsement again, and some insurers will not sell sewer backup unless you already carry it.

Ask two questions on that call: which of those you actually hold, and whether the insurer wants to send its own adjuster before mitigation starts. Emergency mitigation, the extraction and drying, is usually handled separately from the rebuild, so getting the sequence right with the insurer early saves an argument later.

Hours four to six: get a crew in, and understand the clock

The clock that matters is drying, not tidiness. Desa Contracting's Toronto guide says mould begins to grow within 24 to 48 hours and structural damage can start within 72, so the goal of the first day is water out and air moving, not the basement looking normal again.

On price, an emergency extraction or basement pump-out runs $500 to $3,000 per job according to DeSa Contracting (Toronto), and a flooded basement cleanup on an all-in basis runs $4 to $12 per square foot from the same source. Restoration Mate puts water damage in a single area or a few small areas at about $1,500 to $3,500. Ask whether each figure includes 13% HST. The full breakdown with every source named is in the basement flood cleanup cost guide.

In a live flood, book the first qualified company that can start containment tonight rather than waiting to line up three quotes. Compare afterwards, on the rebuild, where you have time.

Afterwards: the Toronto subsidy most people never claim

Once the basement is dry, the City of Toronto Basement Flooding Protection Subsidy is worth an afternoon. As expanded on 1 May 2026 it pays up to $6,650 per property: 80% of the invoiced cost up to $1,600 per backwater valve for a maximum of two devices, $2,250 for a sump pump plus $300 for a battery backup, $500 for a one-time home plumbing assessment, and $400 for weeping-tile severance and capping.

The conditions are specific. The work has to have been completed on or after 12 November 2025, done by a City of Toronto-licensed contractor, under a building permit, with downspouts disconnected, applied for within two years, and with no outstanding City debts on the property.

Backwater valve and sump work is plumbing, not restoration: the City requires a building permit to install a backwater valve, though its permit page says a building permit is not required to install a sump pump. A restoration crew dries the basement out; preventing the next one is a separate job and a separate trade.