French drain installation, repair and replacement in Longueuil
French drain installation, replacement and repair for Longueuil homes. A technician at your home within 48 hours, free quote.
Water in the basement in Longueuil? Your drain may not be the only culprit.
From 2022 to 2024, the City of Longueuil suffered six rain-related floods that caused damage. On August 9, 2024, storm Debby brought as much rain in 24 hours as the city normally receives during the whole month of August.
According to the City’s heavy rainfall resilience strategy (March 2025, published in French), sewers built in the 1970s or earlier, about 31% of the network and mostly in Vieux-Longueuil, combine wastewater, foundation drain water and street runoff in a single pipe. Much of Saint-Hubert and Greenfield Park is served by a pseudo-separate system, where wastewater and foundation drain water also share the same pipe. The City itself lists maintenance of the foundation drain and of backwater valves among the vulnerabilities of buildings.
The City’s by-law CO-2021-1141 governs French drains. Here are the essentials, in plain language.
Perforated pipe of at least 100 mm, covered with a geotextile membrane and surrounded by at least 150 mm of 20 mm clear stone. The top of the drain never goes above the underside of the basement slab (article 85).
The drain empties into a sump pit inside the building. A pump is mandatory there and discharges the water onto a permeable surface on the property, at least 1 metre from the foundations (articles 86 to 90).
The pit connects to the private storm sewer with a cleanout, a trap and a backwater valve, which the owner must keep accessible and working (articles 87, 102 and 107).
It is prohibited to connect gutter downspouts to the foundation drain or to discharge them into the municipal sewer: roof water is released at the surface (article 117).
The by-law prohibits work on a private service connection without a permit from the City (article 5), and that work is at the owner’s expense and responsibility (article 6).
Sources: by-law CO-2021-1141, technical sheets “Drain français” and “Travaux de plomberie” from the City’s Planning and Urban Development Department, and the heavy rainfall resilience strategy of the City of Longueuil. These documents are published in French and were not produced by Solutions Fondation: check the current requirements with the City (311) before the work.
Solutions Fondation in Longueuil
We hold RBQ licence 5816-2793-01 (verifiable in the Régie du bâtiment du Québec registry). Our office is at 2255, Boulevard Industriel, in Chambly, and our technicians travel to Longueuil.
A technician assesses your drain at your home within 48 hours. You then receive a free, detailed quote with no surprises: the price you see is the price you pay. The work is carried out by our own team, with no subcontracting.
Saint-Hubert
Before the drain is replaced, the building inspector assigned to your permit must inspect the existing drain. This inspection determines how the new drain will be connected. The invert of the new drain must be at the same level as the footing’s, and the drain ends in the sump pit.
Vieux-Longueuil
Contact the inspector for your sector before backfilling the French drain and the foundations: they carry out the final inspection. This borough is where most of the city’s combined sewer network is found.
Greenfield Park
Same steps as in Vieux-Longueuil: contact the inspector for your sector before backfilling, for the final inspection. Much of the borough is served by a pseudo-separate system.
In all three boroughs
The City must be notified at least 24 hours before backfilling. It checks the connections before authorizing it, and can require the work to be uncovered, at the owner’s expense, if backfilling was done without its authorization (articles 13 to 15).
A French drain to have inspected in Longueuil?
Our office is in Chambly and we work in Longueuil. A technician comes to your home within 48 hours.
The City of Longueuil handles French drain replacement through a permit: its “Drain français” technical sheet refers to the building inspector “assigned to your permit”, and by-law CO-2021-1141 prohibits work on a private service connection without a permit from the City (article 5). The work is at the owner’s expense and responsibility (article 6).
Check with the City (311) which permit applies to your situation.
Every building with a basement or a cellar must have a French drain around the perimeter of the foundation. It must be a perforated pipe of at least 100 mm in diameter, covered with a geotextile membrane and surrounded by at least 150 mm of 20 mm clear stone. Its top must not go above the underside of the basement concrete slab (article 85). It empties into a sump pit inside the building through a watertight pipe (article 86).
Yes. According to the City’s technical sheet, the existing drain must be inspected before the work by the building inspector assigned to your permit, to determine how the new drain will be connected. The invert of the new drain must be at the same level as the foundation footing’s, its top must never go above the underside of the slab, and it must be discontinuous at the sump pit, with both ends finishing in the pit.
At least 24 hours before backfilling begins (article 13). Before backfilling, the City checks the private connections, the connection and the other works, then authorizes backfilling if there is no non-compliance (article 14). If backfilling was done without authorization, the City can require the work to be uncovered at the owner’s expense (article 15).
Pumped water must discharge onto a permeable surface on the private property, at least one metre from the building’s foundations (article 90). The owner must make sure the pump has sufficient capacity, is well maintained and works (article 91).
Yes. The by-law requires a compliant backwater valve on every connection that receives storm water from outdoor surfaces below the surrounding ground, such as garage ramps and French drains (article 102). The owner must make sure valves are accessible, well maintained and working at all times (article 107). Otherwise, the City is not liable for damage to the building or its contents (article 109).
