On Wednesday, September 2, a storm dropped more than 110 millimetres of rain on parts of Toronto. The City Manager said it met the threshold of a 100-year storm. The Don River overflowed its banks and closed the Don Valley Parkway, and across the city, a lot of people went downstairs that evening and found water where it shouldn’t have been.
In the Beaches and East York, flooding has been a live conversation ever since. And most of the people asking us about it don’t know that the City quietly changed the rules this spring: on May 1, 2026, Toronto almost doubled the money it pays homeowners to protect their basements — from a maximum of $3,400 per property to $6,650.
The money is real. But it was written as a plumbing programme, and most of the basements we work in aren’t plumbing projects. They’re basements in 100-year-old houses that are about to be dug out, underpinned, finished or turned into a suite. In those basements, when the flood protection goes in decides whether you can collect at all.
This is the builder’s guide to the City’s basement flooding subsidy: what it pays, the rules that quietly disqualify East-Toronto houses, and how to build it into a renovation so you get the protection — and the cheque.
What changed on May 1, 2026
The City’s Basement Flooding Protection Subsidy Program pays 80% of the invoiced cost of specific flood-protection work, up to a cap for each item. Since May 1, 2026, the caps are:
- Home plumbing assessment (new) — 80%, up to $500
- Backwater valve, including alarm — 80%, up to $1,600 per device, and up to two devices for houses with more than one sewer connection
- Sump pump, including alarm — 80%, up to $2,250
- Battery backup for the sump pump (new) — 80%, up to $300
- Weeping-tile severance and capping — 80%, up to $400
Add them all up and you reach the $6,650 the City advertises. Most houses won’t use every line, so read $6,650 as a ceiling, not a cheque.
The enhanced amounts apply to work completed on or after November 12, 2025, and you now have two years after the work is finished to apply (it used to be one). Work finished before November 12, 2025 is still eligible under the old caps — $1,250 for one backwater valve, $1,750 for a sump pump, $400 for severance — within one year. The changes were set out in a Toronto Water report to the City’s Infrastructure and Environment Committee in October 2025 and announced in an April 28, 2026 City release.
Two things to know before you count on it: each type of work has a lifetime limit per property, and funding is first-come, first-served and subject to annual approval by City Council. Submitting an application doesn’t guarantee a payment, and the City says it can take up to ten weeks to pay.
Why older East-Toronto basements flood
Most basement flooding in the older city isn’t water coming through the walls. It’s water coming up — out of the floor drain, the laundry tub or the basement toilet — because the sewer under the street is full.
Some of Toronto’s older areas, where the sewers were built as long as a century ago, still have combined sewers: one pipe that carries both sewage and stormwater. In a storm like September’s, that pipe fills, and the water looks for the lowest opening it can find. In a hundred-year-old house, that is your basement floor drain.
Older houses add two problems of their own:
- The foundation drains are often tied into the sewer. In many older homes, the weeping tile around the foundation drains into the City’s sewer system, and the City recommends disconnecting it. A plumber can check the pipe under your basement floor for weeping-tile connections.
- The basement keeps getting deeper. When a basement is lowered or underpinned for headroom or a suite, the new floor drain and fixtures sit even further below the street sewer. A deeper basement is a more valuable basement, and a more exposed one. (Our underpinning guide covers why a lowered basement commits the house to its sump pump for good.)
The two devices the subsidy pays for answer these two problems. A backwater valve is a one-way gate in the main drain that closes when the sewer pushes back. Severing the weeping tile from the sewer and sending it to a sump pump takes the foundation drainage out of the sewer altogether, so the house manages its own groundwater.
The rules that quietly disqualify a house
The subsidy page has a short list of eligibility conditions. In East Toronto, these are the ones that catch people:
- Your downspouts must be disconnected from the sewer (or you need a City exemption). Plenty of older houses still have a downspout running into the ground. Fix it first.
- Front-yard paving has to meet the zoning by-law — and that includes parking pads. If the front yard was paved over decades ago without approval, deal with that question before you apply.
- The contractor and every subcontractor must hold a valid City of Toronto business licence at the time of the work. Not just the company you signed with: the plumber and the drain crew too. Check them on the City’s business licence lookup (or call 416-392-6700) before work starts.
- You must be the registered owner of a single-family house, duplex, triplex or fourplex, with no outstanding taxes or debts owed to the City.
None of these is complicated. All of them are easier to sort out before the floor is open than after.
The sequence: why the timing decides whether you collect
This is the part nobody writes down, because a plumbing page doesn’t have to think about the rest of the basement.
A backwater valve needs a building permit — for a one- or two-unit house, a standalone drain permit with no plans required, per the City’s backwater valve permit guide — and an inspection after it’s installed. The subsidy page is blunt: do not enclose or cover the valve before the inspection is complete.
In a basement renovation, that single rule sets the schedule:
- Assess first. The new subsidised home plumbing assessment is the right first step. A licensed plumber completes the City’s assessment form; you include it with your application, and you don’t have to act on every recommendation. On older houses, we want a camera down the main drain too — to see what it’s made of, where it runs, and whether there’s more than one connection (which is where the second valve comes in).
- Design the floor around the valve. The valve has to stay accessible for cleaning for the life of the house. In a finished basement, that means a cleanout access in the floor in a place you’ll be happy to see it — not under the new vanity.
- Permit before the trench. The drain permit is in hand before the main is cut.
- Install, then inspect, then pour. The valve and the sump pit go in while the floor is open; the City inspects the valve before the new slab, the subfloor or the finished floor covers it.
- Photograph the sump. For the sump pump, the City wants photos of the pump and of the exterior discharge pipe with your application.
- Invoice it properly. The City wants original electronic invoices with the contractor’s name and address, the property address, the completion date, an itemised breakdown and a total marked “paid in full.” Ask for the sump pump and the battery backup to be itemised separately — the City asks for that — and we’d itemise each valve too.
Get that order wrong and the cost is real: a floor poured over an uninspected valve has to be opened again.
If the basement is becoming a suite or a lowered floor
Most of the basements we open are being turned into something: a family room with real headroom, a legal basement apartment, or a suite for a parent. Three things change when that’s the plan:
- The stakes go up. A flooded storage room is a mess. A flooded suite is someone’s home, their belongings, and a rental income stopped.
- The depth goes up. Lowering the floor puts every fixture further below the sewer. Whether a backwater valve is required for a given set of fixtures is something your plumber and the plans examiner confirm on your drawings — but in a lowered basement in the older city, we’d want one in either way.
- The subsidy still applies. The programme covers single-family houses through fourplexes, so a house that’s adding a unit is still eligible.
Flood protection is also the cheapest it will ever be when the floor is already out. That’s the same argument as the order you do things in generally: the work that’s buried belongs at the start.
What the subsidy doesn't cover
- Water coming through the walls. Cracked or leaking foundation walls are a waterproofing question — exterior membrane, interior drainage, or both — and aren’t part of this programme. On rubble and brick foundations, we look at waterproofing and underpinning together.
- Grading and the lot. Soil sloping toward the house, a low window well, a walkout stair with a blocked drain: none of that is plumbing, and all of it puts water against the wall.
- Your insurance. The subsidy protects the basement; it doesn’t change your policy. Ask your insurer whether they want to know about the valve and sump. Some do.
While the floor is open
A basement floor in a hundred-year-old house only comes up once a generation. While it’s open, it’s worth asking what else is under there: the material of the water service coming in from the street, the condition of the main drain beyond the valve, and where the old cast-iron and clay pipe meet the new. The knob-and-tube logic applies here too — find out what you have before you cover it.
Woodsmith Insight: The best flood protection in an old house is the protection you put in while the basement is already open — and the City will now pay for most of it. The trick isn’t the valve. It’s the order: assess, permit, install, inspect, then build the room on top. Get that right and you get a drier house and the cheque. Get it wrong and you’re cutting a new floor to show an inspector a valve.
— Christopher B. Smith, Red Seal carpenter and BCIN-licensed designer
Frequently asked questions
Up to $6,650 per property for work completed on or after November 12, 2025: 80% of the invoice up to $500 for a home plumbing assessment, $1,600 per backwater valve (up to two), $2,250 for a sump pump, $300 for a battery backup and $400 for weeping-tile severance and capping.
Almost. The maximum went from $3,400 to $6,650 on May 1, 2026, and the City describes it as almost doubling the support available.
If the work was completed on or after November 12, 2025, you can apply under the new amounts within two years of completion. Work completed before that date is eligible at the old amounts within one year.
Yes. A backwater valve needs a building permit and an inspection after installation, and the City says not to enclose or cover it before the inspection is complete.
Yes. The programme covers registered owners of single-family houses, duplexes, triplexes and fourplexes.
Common reasons are downspouts still connected to the sewer, a front-yard parking pad that doesn’t meet zoning, a contractor or subcontractor without a valid City business licence, missing permit or inspection for a backwater valve, or invoices that aren’t itemised and marked paid in full.
It depends on where the fixtures sit relative to the sewer, and your plumber and the plans examiner confirm it for your drawings. In a lowered basement in the older city, we recommend one regardless.
No. It covers the plumbing assessment, backwater valves, sump pump, battery backup and weeping-tile severance. Leaking foundation walls are a separate waterproofing question.
Sources
- City of Toronto — Basement Flooding Protection Subsidy Program (modified June 18, 2026)
- City of Toronto — “City of Toronto to almost double the amount of basement flooding subsidies starting May 1” (April 28, 2026)
- Toronto Water — report to Infrastructure and Environment Committee, “Enhancing the Basement Flooding Protection Subsidy Program” (October 14, 2025)
- City of Toronto — Standalone drain permit for a backwater valve (modified July 14, 2026)
- City of Toronto — How to Prevent Basement Flooding (modified April 17, 2026)
- City of Toronto — Combined Sewer Overflows
- CP24 — “One for the history books: a look at how Wednesday’s wild storm in Toronto took shape” (September 3, 2026)
- CP24 — “A 100-year storm: DVP reopens as cleanup continues across Toronto” (September 3, 2026)
