Downspout Disconnection Rules in Toronto and Montréal

Yes, both cities require it. In Toronto, every property owner must make sure their downspouts are disconnected from the City sewer, with exemptions only where disconnection is not technically feasible or would create a hazard. In Montréal, roof water from a sloped roof cannot go into the foundation drain, onto a paved surface or toward the street: it has to land on a permeable surface such as a lawn or flower bed, at least 1.5 metres from the foundation.

These rules exist for the same reason. During a heavy rain, roof water poured straight into the sewer helps overload it, and in older neighbourhoods with combined sewers that can mean sewage backing up into basements, including your own. The rules below are a plain summary for homeowners. The bylaw text always wins over any summary, so check your city's current wording before you start work.

What "connected" actually means

A downspout is connected when it runs into a pipe that disappears into the ground at the base of the wall. That pipe usually leads to the weeping tile around the foundation, to a storm lateral or, in older homes, straight to the sanitary or combined sewer. Many houses built before the 1980s were plumbed this way on purpose, so a connected downspout is not a sign that a previous owner cut corners.

A disconnected downspout ends above ground. It turns out at the bottom through an elbow, then runs through an extension, a splash pad or a surface channel that carries the water away from the house and lets it soak in.

Toronto: the mandatory disconnection bylaw

Toronto's rule sits in Chapter 681 (Sewers) of the Municipal Code. The City's position is simple: it is mandatory for all property owners to have their downspouts disconnected from the sewer system.

A few points owners often miss:

• Exemptions are per downspout. If one corner of the house cannot be disconnected safely, that does not excuse the other three. The City decides on each connected downspout separately and answers in writing.
• You have to try first. Before applying for an exemption, the owner is expected to make every reasonable effort to disconnect, such as moving the downspout or correcting the grading so water flows away.
• The application needs a sketch. The exemption form asks for a property sketch showing the downspouts, the house, the lot lines and where water would go. Reviewers look at whether downspouts could be relocated, whether hazards could be fixed and whether disconnection would conflict with other bylaws.
• Exemptions can be pulled back. If the information turns out to be inaccurate or the property changes (an addition, a new driveway, regrading), the City can revoke the exemption.

Typical grounds for an exemption are narrow lots where the only place for the water is a neighbour's yard or a shared walkway, or spots where the discharge would freeze across a sidewalk or stairs. Toronto has also offered financial help for disconnection to eligible owners (seniors and low-income households, for example). The program details change, so look for the current form on toronto.ca before counting on it.

Montréal: where roof water has to go

Montréal's stormwater rules come from by-law 20-030, the by-law on connections to the public water and sewer networks and on stormwater management. The City's own guidance for homeowners boils it down to three prohibitions and one requirement.

Not allowed:

1. Connecting a gutter to the foundation drain.
2. Pointing a downspout at an impermeable surface such as a driveway, patio or walkway.
3. Sending the water toward the street.

Required: the water from the gutter (or from the overflow of a rain barrel) has to reach a permeable surface, such as a planted bed or lawn, at least 1.5 m from the foundation.

The City has said this requirement comes from article 89 of by-law 20-030 and that the law provides no exemption, so the small-lot exemption route that exists in Toronto is not really available. Fines are possible, and the borough office is the place to ask about enforcement on your street. Other Quebec municipalities have their own versions, and some set a longer minimum distance, so a house in Laval or Longueuil should be checked against that city's by-law, not Montréal's.

Flat roofs are a different story. Their drains are designed for the building's internal plumbing and are not covered by the same homeowner gutter rules.

Other cities

Plenty of cities in Canada and the US have pushed homeowners to disconnect, especially older ones with combined sewers. Some made it mandatory, others ran voluntary programs with rebates or free kits, and a few moved on to rain barrel or rain garden incentives once most homes were done. Before you hire anyone, search "downspout disconnection" with your city's name and read the municipal page itself, not a forum thread. The thing to find out is whether disconnection is required, how far from the wall the water must land, and whether you need a permit to cap the old pipe.

How a proper disconnection is done

The work itself is usually small, but doing it badly just moves the water problem somewhere else. A sound job includes:

• Cutting the downspout about 20 to 25 cm above the standpipe and adding an elbow so it turns out away from the wall.
• Capping the standpipe with a watertight cap so roof water, soil and pests cannot get in. A loose cap leaks back into the same drain you just disconnected.
• Adding an extension or channel long enough to clear the wall by your city's minimum (1.5 m in Montréal) and pointed at grass or a bed, never at a neighbour's property, a driveway or a window well.
• Checking the grade. The ground should slope away from the house. If the soil around the foundation slopes inward, the water runs right back.
• Thinking about winter. In Canadian winters, extensions can freeze solid or be crushed by a snow blower. Hinged or flip-up extensions and a splash pad on a slight slope hold up better than a loose length of corrugated pipe.

Sometimes the gutters themselves are part of the trouble. A run pitched the wrong way, a downspout placed in a spot with no lawn nearby, or a single outlet draining too much roof all make disconnection harder. Moving an outlet or adding a second downspout can turn an awkward location into an easy one, and it is worth asking about before applying for any exemption.

Frequently asked questions

Is downspout disconnection mandatory in Toronto?

Yes. Toronto requires all property owners to have their downspouts disconnected from the City sewer system under Chapter 681 of the Municipal Code. An owner who believes disconnection is not technically feasible or would create a hazard can apply for an exemption, which the City decides downspout by downspout.

How far from the house does a downspout have to drain in Montréal?

Montréal's guidance says water from gutters must reach a permeable surface, such as a lawn or flower bed, at least 1.5 metres from the foundation. It cannot be piped into the foundation drain, aimed at pavement or sent toward the street.

Can a downspout drain onto the driveway?

In Montréal, no: discharging onto an impermeable surface is prohibited. In many other cities it is discouraged because the water can run back toward the house, freeze into a slip hazard or flow onto a neighbour's lot, so a lawn or planted bed is the safer target.

Does disconnecting downspouts cause basement leaks?

It can if the water lands too close to the wall or the ground slopes toward the house. With a long enough extension, a capped standpipe and grading that slopes away from the foundation, disconnection usually lowers the load on the foundation drain rather than raising it.

Get your downspouts sorted

If your downspouts still disappear into the ground, or the extensions dump water next to the wall, tell us about the house through the quote form. A specialist who works in your area can look at the downspouts, the gutters feeding them and the grading, then put the fix in a written quote. Local pages for Toronto and Montréal cover the service areas in more detail.