Discovering a blocked drain is stressful enough without having to work out who should pay to clear it. You might be dealing with wastewater backing up, an overflowing outside drain or a problem affecting neighbouring properties. But should you call a drainage specialist, contact your water company or ask your landlord to investigate?
The answer depends on where the blockage is, which properties the affected pipe serves and whether it forms part of the public sewer network. Getting this right can help you avoid arranging unnecessary work or paying to repair pipework that is not your responsibility.
Maintracts provides drainage services across London, including drain unblocking, CCTV drain surveys, drain tracing and repairs. Understanding where the problem lies is the first step towards finding the right solution.
Who is responsible for private drains, lateral drains and public sewers?
The distinction is important because a pipe's location alone does not always establish who must maintain it.
Private drains: usually the property owner's responsibility
Private drains carry wastewater from a property towards a sewer or another drain. The property owner is generally responsible for maintaining and repairing the private drainage serving their premises.
If a blockage occurs in this section, the owner will usually need to arrange clearance. If the problem is caused by damaged pipework, displaced joints or root ingress, further investigation and repairs may also be necessary.
Lateral drains: often the water company's responsibility
A lateral drain carries wastewater from a property towards a public sewer. It often extends beyond the property boundary, beneath a pavement or road.
In England, adopted lateral drains are generally maintained by the relevant water company. However, some privately owned or unadopted arrangements remain. If you are unsure, ask your water company to check its sewer records and confirm whether the affected pipe is part of its network.
Public sewers: contact the relevant water company
Public sewers collect wastewater from multiple properties. The relevant water and sewerage company is generally responsible for their maintenance and repair.
A public sewer may run beneath a private garden or driveway. Its location does not automatically make the landowner responsible for maintaining it.
| Drainage problem | Usual next step |
| Blockage in a private drain serving your property | Arrange professional investigation or clearance |
| Suspected blockage in an adopted lateral drain | Contact your water company |
| Suspected public sewer blockage | Report it to your water company |
| Unclear ownership or shared drainage | Ask the water company to confirm the pipe's status |
These are general guidelines for England. Private and unadopted drainage arrangements can differ, so confirm responsibility before commissioning repairs.
How can you tell where a blockage is occurring?
The symptoms provide useful clues, but they do not prove where a blockage lies or who owns the affected pipe.
If only one fixture is affected, the restriction may be in the local waste pipe or branch serving it. If several sinks, toilets or other fixtures are backing up, the problem may be further along the drainage system.
An overflowing external inspection chamber can indicate a downstream restriction, but the location of the chamber and the connections between pipes matter. If neighbouring properties experience similar problems, a shared drain or public sewer may also need investigating.
This is where identifying the drainage route becomes important. Maintracts' drain tracing service can help locate hidden pipework and establish its route and position. This is particularly useful where drainage layouts are unclear, or several properties share underground pipework.
Drain tracing helps establish where pipes run; it does not, by itself, determine legal ownership. The water company may still need to confirm whether a particular section is adopted.
When is a CCTV drain survey or repair needed?
Once the affected pipework has been identified as private, the next step is to establish whether it needs clearing, inspecting or repairing.
A straightforward obstruction may be resolved through professional drain unblocking. Maintracts also offers drain jetting, which can remove suitable blockages using high-pressure water.
However, if a blockage keeps returning, simply clearing the pipe may not address the underlying problem. A CCTV drain survey allows the internal condition of accessible pipework to be examined, helping identify issues such as root intrusion, displaced joints, cracks or structural damage.
If the survey identifies a defect, the appropriate repair will depend on its location and severity. Maintracts provides drain repairs in London, including drain relining and excavated repairs where required.
For example, if a drain repeatedly blocks and a CCTV survey reveals a damaged section, further clearance alone is unlikely to provide a lasting solution. Establishing the cause helps determine whether repair work is needed.
These services are intended for drainage issues within the relevant private or client-managed system. If the water company confirms that the problem lies within its public network, report it to the company rather than arranging private repairs to that section.
What if a blocked drain serves several properties?
Shared drainage can be particularly confusing in converted houses, blocks of flats and properties with common underground pipework.
In England, many existing private sewers and lateral drains connected to the public sewer network transferred to water and sewerage companies on 1 October 2011. You can read more about the transfer of private sewers in England.
Some privately owned or unadopted systems still exist. If responsibility is unclear, ask the water company to check its records and consult the relevant property documents where necessary.
If the drainage system is privately owned, the owners responsible for it may need to arrange and fund the work. Where the pipe route is uncertain, a drainage investigation can help establish which sections serve the affected properties.
What should you do if your drain is blocked?
If wastewater is backing up or an external drain is overflowing, avoid using affected fixtures and seek professional advice promptly. Do not lift heavy inspection covers or attempt to investigate a suspected sewage blockage yourself.
Start by checking whether the problem affects one fixture, several fixtures or neighbouring properties. Contact your water company if a public sewer or adopted lateral drain may be involved.
If the issue is within your private drainage system, Maintracts can help investigate the cause and determine whether clearance, tracing, a CCTV survey or repairs may be appropriate. Our blocked drain clearance and repair services provides a practical next step for residential and commercial drainage problems across London.
Establishing the location and condition of the affected pipework helps you choose the right course of action instead of paying for work on a section that may not be your responsibility.