Drain unblocking in Brussels, Flanders and Wallonia

Checked on 2 October 2026

1. In the Brussels region, Vivaqua is responsible for maintaining, managing and keeping in working order the sewer connection. Its responsibility stops at the boundary between the public domain and the subscriber’s cadastral plot.

   Source:vivaqua.be

2. In the Brussels region, the subscriber or user is responsible, at their own cost, for maintaining and safely operating the private drainage installations, including the rainwater downpipe along its whole length.

   Source:vivaqua.be

3. In the Brussels region, only Vivaqua may work on connections to the water and sewer networks. If its intervention is due to the subscriber’s fault or installations, the subscriber pays the costs.

   Source:vivaqua.be

4. In the Brussels region, it is forbidden to obstruct the sewer network, for example with wet wipes or concrete, or to discharge unauthorised fats into it. The cost of any damage is charged to the person responsible.

   Source:vivaqua.be

5. In the Brussels region, the private drainage installation must stay fully watertight at least up to street level, even when the public sewer is surcharged, with no opening that would let sewage back up into the plot.

   Source:vivaqua.be

6. In the Brussels region, in certain connection layouts, Vivaqua advises the subscriber to fit a non-return valve on the connection at the edge of the private domain. The subscriber installs and maintains it at their own cost.

   Source:vivaqua.be

7. In the Brussels region, Vivaqua offers a free flooding guidance service: on request, its advisers examine the installation and determine a suitable solution, such as diverted pipes, pumps or valves.

   Source:vivaqua.be

Checked on 2 October 2026

1. In Flanders, under the General Water Sales Regulation (Algemeen Waterverkoopreglement), the house connection (huisaansluiting) is the drain pipe running from the main sewer up to the rooilijn, the line between private land and the public domain. The private drainage (privéwaterafvoer) is the set of pipes, channels and appliances upstream of the rooilijn.

   Source:codex.vlaanderen.be

2. In Flanders, only the sewer operator may install, modify, maintain and repair the house connection (huisaansluiting). The house connection is the property of the sewer operator.

   Source:codex.vlaanderen.be

3. In Flanders, the sewer operator bears the cost of work on the house connection. It may ask the customer for a contribution when the customer requests the work or when the work is needed because of damage or a fault the customer caused.

   Source:codex.vlaanderen.be

4. In Flanders, the customer or owner is responsible for installing, modifying, repairing and maintaining the private drainage and for keeping it in working order, and bears all related costs.

   Source:codex.vlaanderen.be

5. In Flanders, where Farys runs the sewers, Farys states that owners are responsible for draining rain and waste water on their private land and that the sewer operator takes over from the rooilijn, the line between private land and the public domain. If the inspection chamber (toezichtputje) is empty, the blockage is in the private part and the owner has the unblocking or repair carried out.

   Source:farys.be

6. In Flanders, in municipalities where Fluvius is the sewer operator, Fluvius’s technical regulation places the maintenance of the private drainage and of the part of the house connection up to and including the connection inspection chamber (huisaansluitputje) on the customer. In case of a blockage, the customer must first check that it lies beyond that chamber before calling the operator.

   Source:fluvius.be

7. In Flanders, the private drainage must be inspected for a new build or rebuild, for a new additional house connection or the installation of an individual treatment system, and when a separate sewer system is laid in the public domain, unless there is an inspection for a new build or rebuild no more than five years old.

   Source:codex.vlaanderen.be

8. In Flanders, customers request the private drainage inspection themselves and pay for it. AquaFlanders and Vlario train and accredit the inspectors.

   Source:vmm.vlaanderen.be

9. In Flanders, complete separation of wastewater and rainwater from roofs and ground surfaces is mandatory as soon as a separate sewer system is laid or relaid, unless the implementation plan provides otherwise.

   Source:codex.vlaanderen.be

10. In Flanders, where household wastewater goes is not a free choice: the municipal zoning plan sets, address by address, how it must be handled.

    Source:vmm.vlaanderen.be

11. In Flanders, buildings in the individually optimised rural area must eventually have their own wastewater treatment system (IBA). For new builds it must be installed immediately; for existing buildings, the municipality or sewer operator makes contact when the IBA has to be installed.

    Source:vmm.vlaanderen.be

12. In Flanders, in the individually optimised rural area, a septic tank receiving both black and grey wastewater, with a capacity of at least 3,000 litres, is mandatory pending an IBA.

    Source:vmm.vlaanderen.be

13. In Flanders, emptied septic tank material may not be discharged into public sewers or collectors; it must be taken to a public wastewater treatment plant.

    Source:codex.vlaanderen.be

Checked on 2 October 2026

1. In Wallonia, connecting a dwelling to the public sewer requires prior written authorisation from the municipal executive (collège communal). Connection works on the public road domain are carried out under the municipality’s supervision, and the municipality sets the fee and the terms for that work.

   Source:wallex.wallonie.be

2. In Wallonia, the connections of dwellings to the sewer and to other water discharge systems must have an accessible inspection chamber (regard de visite), placed where the quantity and quality of the water actually discharged can be checked.

   Source:wallex.wallonie.be

3. In Wallonia, dwellings along a road that already has a sewer must be connected to it, and dwellings along a road where a sewer is being laid must be connected during the sewer works. Once a dwelling is connected, grey water and black water are discharged exclusively through the sewer network.

   Source:wallex.wallonie.be

4. In Wallonia, every new dwelling must have a system that separates all rainwater from waste water. Where the road has a separate sewer (égout séparatif), discharging rainwater and clean parasitic water into it is prohibited.

   Source:wallex.wallonie.be

5. In Wallonia, any dwelling built after the date on which the municipal general sewerage plan or the PASH (sub-basin sanitation plan) first placed it in an autonomous sanitation zone must be equipped with an approved individual treatment system (système d’épuration individuelle).

   Source:wallex.wallonie.be

6. In Wallonia, septic tanks are emptied of their sludge by an approved emptier (vidangeur agréé) when the stored sludge reaches seventy percent of the total height below water level.

   Source:wallex.wallonie.be

7. In Wallonia, when the operator of an individual treatment system is not exempt from the sanitation charge (CVA, coût-vérité assainissement), the SPGE, with the competent sanitation body, has the excess sludge emptied at its own expense within the deadline set by the maintenance report or after a periodic control.

   Source:wallex.wallonie.be

8. In Wallonia, maintenance of every individual treatment system is carried out under the operator’s responsibility, following the terms and minimum frequency set by the decrees implementing the environmental permit legislation. When the operator is not exempt from the CVA, the SPGE contributes financially to each maintenance visit.

   Source:wallex.wallonie.be

9. In Wallonia, for a building connected to the water supply for the first time, the mandatory CertIBEau includes a part on the discharge and treatment of waste water and rainwater, and the compliance it certifies is required before the connection is put into service for good.

   Source:wallonie.be

Checked on 2 October 2026

1. In Belgium, in a co-owned building, where the title deeds are silent or contradictory, the parts of buildings or land used by all co-owners, or by some of them, are deemed to be common parts.

   Source:ejustice.just.fgov.be

2. Co-ownership charges, in particular maintenance, repair and renovation costs, are shared according to the respective value of each private unit, unless the parties decide to share them in proportion to the usefulness for each private unit.

   Source:ejustice.just.fgov.be

3. The syndic (building manager) is responsible for carrying out, and having carried out, the decisions of the general assembly, and for performing all protective acts and all acts of provisional management.

   Source:ejustice.just.fgov.be

4. In Belgium, the general assembly of a co-ownership decides by a two-thirds majority of the votes on all works affecting the common parts. Works required by law and protective or provisional management works can be decided by an absolute majority of the votes of the co-owners present or represented.

   Source:ejustice.just.fgov.be