How much does it cost to regrade around a house in Toronto?

Two Ontario sources price it, and they describe it differently. Project Landscaping puts proper grading around the home at $1,500 to $4,000. OCM Excavation puts land grading only on a residential lot at $1,500 to $6,000, and separately notes that a small job such as a back-yard regrade can come in under $3,000. A narrower drainage correction, rather than a whole-lot regrade, is $1,500 to $5,000 per Gamcon, over two to five days.

What does a downspout extension cost?

Almost nothing, which is the entire point of this page. Custom Contracting prices a downspout extension or splash pad at $20 to $60 each and an elbow at $30 to $75. Doing it properly, meaning longer runs taken somewhere the water can actually go, is $200 to $800 per downspout according to Project Landscaping. Burying the line to a proper outlet is $500 to $2,500 per connection. A whole house of four downspouts extended is often under $200 in parts.

Does fixing the grading actually stop a wet basement?

Sometimes entirely, and the City of Toronto treats it as a real cause rather than a nicety: poor lot grading or drainage, overflowing eavestroughs and leaking or plugged downspouts sit on its list of what causes basement flooding, alongside weeping tile failure and sewer backup. A roof sheds an enormous volume in a storm, and a downspout emptying at the wall delivers all of it straight to the footing. Whether it is your only problem is a different question, but it is the cheapest one to eliminate.

How far should a downspout discharge from the foundation?

Far enough that the water leaves rather than soaks in beside the footing, and onto ground that falls away from the house rather than back toward it. An extension that ends on ground sloping the wrong way has moved the problem two metres, not solved it. This is why the grading question and the downspout question are really one question, and why the calculator above prices them together.

Should I do this before paying for waterproofing?

It is the one item on this site where doing it first and watching what happens is a rational plan rather than a gamble. Gamcon publishes drainage correction as a two-to-five-day job with a lifespan of 15 years and up, at $1,500 to $5,000. Full waterproofing is five figures. If surface water is the whole problem, you have saved the five figures. If it is not, you have eliminated a variable and spent a small fraction of the alternative doing it.

What does fixing the downspouts and grading cost?

Last updated: August 26, 2026By Below-Grade Records Desk

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This is the cheapest item on the City of Toronto's own list of what causes basement flooding, and it sits on that list next to weeping tile failure and sewer backup. A splash pad is twenty dollars. Regrading a lot is a few thousand. Full waterproofing is five figures. Whatever else is wrong, this is the part worth eliminating first.

Price the cheap fix first

What do the downspouts need?

Just get the water away from the wallAn extension or a splash pad on the end of the existing downspout. The cheapest thing on this entire website, and often the whole fix.Extend it properly and correct the drainageLonger runs, re-pitched, taken somewhere the water can actually go rather than to the next low spot.Bury it and take it away undergroundA buried line to a proper outlet. Tidy, permanent, and the expensive version.Replace the downspout itselfWhere the downspout is leaking, detached or crushed rather than just too short.The downspouts are fineThen it is a grading job.

How many downspouts?

Walk round the house and count them. Four is typical on a detached, two on a semi.

downspouts

Which way does the ground fall?

The ground already falls away from the houseThen leave it alone. Grading that works is grading that does not need paying for.One area slopes the wrong way and needs correctingA drainage correction rather than a whole-lot regrade.Regrade around the houseBringing the ground back to falling away from the foundation on every side.

What this fix costs in the GTA

$2,599–$9,266

with 13% HST. Before tax that is $2,300–$8,200.

Extend it properly and correct the drainage, x4$200–$800 eachProject Landscaping: $800–$3,200
One area slopes the wrong way and needs correctingGamcon: $1,500–$5,000
HST at 13%Government of Ontario: $299–$1,066

Toronto requires the disconnection anyway. To take the City’s flood subsidy on a backwater valve or a sump pump, “the downspouts from the property’s eavestrough must be disconnected from the City’s sewer system or you must have been granted an exemption by the City.” And the City is equally clear that the disconnection itself “is not eligible for a subsidy”, so this is a cost you carry to unlock the ones you do not.

How long it lasts. Gamcon publishes drainage correction as a two-to-five-day job with a lifespan of 15 years and up. Against a five-figure waterproofing bill with a 30-to-50-year life, this is the one on the list where doing it first and seeing what happens is a rational plan rather than a gamble.

Four Ontario sources, widened only where they describe the same scope. The City of Toronto lists poor lot grading, overflowing eavestroughs and leaking or plugged downspouts as causes of basement flooding in their own right, next to weeping tile failure and sewer backup. This is the cheap one on that list.

Method

How this estimate is built

Four Ontario sources price this work and WaterproofingIndex read all four in August 2026. Downspout figures are widened across the rows that describe the same scope, multiplied by how many downspouts you have, and 13 per cent HST is added.

The two grading figures are deliberately NOT widened together. Project Landscaping prices “proper grading around your home” and OCM Excavation prices “land grading only” on a residential lot. Those are a landscaper's scope and an excavator's scope, described in each company's own terms, and blending them into a single band would put an excavator's ceiling on a landscaping quote. Both are shown, each named.

What no source can tell you is whether this is your whole problem. The honest framing is the one on the City's page: surface water is one cause of a wet basement among several, and it happens to be the cheap one.

Comparison

What to look at, in the rain, for free

Follow each downspout to its end. Anything discharging within a metre of the wall is the first thing to change, and it costs twenty dollars.
Put a level on the ground two metres out. Ground that has settled back toward the house over thirty years is the commonest version of poor grading and it is invisible until you measure.
Watch the eavestroughs during a real downpour. Overflowing gutters put the whole roof's water in one place, and the City lists that as a cause in its own right.
Look at where the extension ends, not just how long it is. An extension finishing on ground that slopes back has moved the problem two metres rather than fixed it.
Check the window wells while you are out there. A well packed with soil or holding water is doing the same job as a downspout at the wall, more quietly.

Frequently asked questions

How much does it cost to regrade around a house in Toronto?: Two Ontario sources price it, and they describe it differently. Project Landscaping puts proper grading around the home at $1,500 to $4,000. OCM Excavation puts land grading only on a residential lot at $1,500 to $6,000, and separately notes that a small job such as a back-yard regrade can come in under $3,000. A narrower drainage correction, rather than a whole-lot regrade, is $1,500 to $5,000 per Gamcon, over two to five days.
What does a downspout extension cost?: Almost nothing, which is the entire point of this page. Custom Contracting prices a downspout extension or splash pad at $20 to $60 each and an elbow at $30 to $75. Doing it properly, meaning longer runs taken somewhere the water can actually go, is $200 to $800 per downspout according to Project Landscaping. Burying the line to a proper outlet is $500 to $2,500 per connection. A whole house of four downspouts extended is often under $200 in parts.
Does fixing the grading actually stop a wet basement?: Sometimes entirely, and the City of Toronto treats it as a real cause rather than a nicety: poor lot grading or drainage, overflowing eavestroughs and leaking or plugged downspouts sit on its list of what causes basement flooding, alongside weeping tile failure and sewer backup. A roof sheds an enormous volume in a storm, and a downspout emptying at the wall delivers all of it straight to the footing. Whether it is your only problem is a different question, but it is the cheapest one to eliminate.
Do I have to disconnect my downspouts in Toronto?: To claim the City's flood subsidy, yes. The programme's own wording is that the downspouts from the property's eavestrough must be disconnected from the City's sewer system, or you must have been granted an exemption by the City. The City is just as clear that the disconnection work itself is not eligible for a subsidy. So it is a cost you carry in order to unlock up to $6,650 of the ones you do not.
How far should a downspout discharge from the foundation?: Far enough that the water leaves rather than soaks in beside the footing, and onto ground that falls away from the house rather than back toward it. An extension that ends on ground sloping the wrong way has moved the problem two metres, not solved it. This is why the grading question and the downspout question are really one question, and why the calculator above prices them together.
Should I do this before paying for waterproofing?: It is the one item on this site where doing it first and watching what happens is a rational plan rather than a gamble. Gamcon publishes drainage correction as a two-to-five-day job with a lifespan of 15 years and up, at $1,500 to $5,000. Full waterproofing is five figures. If surface water is the whole problem, you have saved the five figures. If it is not, you have eliminated a variable and spent a small fraction of the alternative doing it.

Sources

Where these numbers came from

Four Ontario price lists plus the City of Toronto's subsidy conditions, each read on its own page in August 2026 and stored with the sentence carrying the figure. Canadian dollars, before HST.

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