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Responsibility follows the pipe, not the postcode. If the blocked pipe serves only your building and sits inside your boundary, it is usually yours. Once it crosses your boundary, or once it serves a second property, it is usually your water company’s — and has been since the private sewer transfer of 1 October 2011. Below: the rules in plain English, a checker that walks you through it, and the sources for every claim.
Run the responsibility checkerThese are the general rules for England and Wales. There are real exceptions — newer unadopted pipework, private roads, and anything your lease says otherwise about. Everything on this page is guidance, not legal advice: confirm your own position with your water company before you pay for work.
Four questions, about thirty seconds. It tells you who is usually responsible for the pipe you are describing, and what to do next.
JavaScript is switched off, so the checker is showing all of its questions at once. Answer them in your head and read your result in the outcome table underneath — the rules are identical either way.
Guidance, not legal advice. The checker applies the general rules for England and Wales and cannot see your pipework, your deeds or your lease. Confirm your own position with your water company before you pay for work or refuse to.
| Where the blockage is | Does the pipe serve anyone else? | Who is usually responsible |
|---|---|---|
| Inside the building | Not asked | Usually you — it is inside the building |
| Outside, on my property | It serves only my building | Usually you, as the property owner |
| Outside, on my property | It is shared with one or more neighbours | Usually your water company |
| Outside, on my property | I do not know | It turns on one question: does that pipe serve anyone else? |
| Outside, past my boundary | Not asked | Usually your water company |
| In the road or pavement itself | Not asked | Usually the council — sometimes the water company |
| I am not sure where it is | Not asked | Not enough to call it yet — but this takes about ten minutes to settle |
Property type and tenure do not change who owns the pipe — they change who you speak to first. If you rent, report it to your landlord; if you live in a flat, your lease and managing agent come first; if the premises are commercial, read the repairing clause. Those notes are added to whichever row applies to you — except the road-gully row, where how you hold the property makes no difference at all.
Nearly every argument about a blocked drain comes down to people using the word “drain” for three different things. The law does not. Get the name right and the answer usually falls out of it.
Before 2011, if you shared a drain run with your neighbours, the whole run was private. Six houses on a Victorian terrace shared one pipe, and when it collapsed, six households argued about the bill. That is the world a lot of advice online still describes, and it is fifteen years out of date.
The Water Industry (Schemes for Adoption of Private Sewers) Regulations 2011 changed it. Private sewers and private lateral drains that communicated with the public sewer as at 1 July 2011 were adopted by the sewerage company for the area, with the transfer taking effect on 1 October 2011. Pumping stations followed by 1 October 2016. 2
In practice that means two things. First, the shared run behind the terrace is now almost certainly the water company’s. Second, the stretch of your own drain beyond your boundary is theirs too. What is left to you is a shorter length of pipe than most people assume.
The exception worth knowing. The transfer captured pipework connected before 1 July 2011. Drainage laid on a development since then, and never formally adopted, can still be private — and if it serves several homes, private and shared. If your property is on a newer estate, ask your water company whether the run has been adopted before you accept a bill for it. 2
This is the single most common misunderstanding we are called about, and it costs householders money every week.
Because a pipe serving more than one building is a sewer, not a drain, a shared run is not the kind of thing an individual householder is normally responsible for. 1 Combine that with the 2011 transfer and the position for most shared runs is straightforward: report it to the water company, do not split the bill with the neighbours.
Two practical tests tell you whether you are on a shared run. Lift the chamber lid nearest the blockage and count the pipes coming in — more than one inlet usually means more than one property. Ask next door whether their sinks are slow too. Terraces, semis and older estates share far more often than people expect.
One thing that has not changed: a shared run does not become your neighbour’s problem because the blockage happens to sit under their garden. Ownership of the land above a pipe does not decide ownership of the pipe.
The pipe rules decide who owns the problem. Who you should actually speak to first depends on how you hold the property.
The simplest case: the pipe rules apply directly. Inside your boundary and serving only you, it is yours. Past the boundary, or shared, it is usually the water company’s.
Your lease is the first document to read, not the water company’s website. The shared stack and the pipework in the common parts are normally handled through the building’s management, and GOV.UK is explicit that your lease sets out what the service charge covers. Report it to the managing agent or freeholder before you instruct anyone. 8
Report it to your landlord or agent, in writing, and keep the date. For most tenancies granted for a term of under seven years, the Landlord and Tenant Act 1985 requires the landlord to keep the structure and exterior of the dwelling-house in repair — “including drains, gutters and external pipes”. 67
The same Act puts that obligation on you where the tenancy was granted for under seven years. Where the blockage turns out to be in a lateral drain or a shared run, it is still the water company’s pipe — you are not liable for it just because you own the house. 67
The pipe rules are unchanged, but commercial leases commonly put repairing obligations on the occupier, including drainage inside the demise. Check the repairing clause before anyone commits to the cost.
Where the road itself is unadopted, the drainage under it may be too — and the position varies. This is the case where “check with your water company” is not a hedge but the actual answer.
They will deal with blockages in public sewers and in lateral drains beyond your boundary. Southern Water — the sewerage undertaker across our patch in Sussex — say they will clear the blockage outside the property, make sure everything is flowing, and clear and disinfect the garden and hard surfaces afterwards. 4
They will not touch a private drain inside your boundary that serves only your building. Southern Water put it directly: private drains are usually owned by the property owner and maintenance is their responsibility — if the problem is on your property, you will need a drainage specialist. 4
They may charge in one situation, and it is the only charge their published blocked-drain guidance mentions: Southern Water note they may charge where they have been called back more than once to a blockage in the same place. Anything beyond that — what you are and are not billed for — is a question for your own water company, and not something we will state on their behalf. 4
If you genuinely cannot tell whose pipe it is, call them anyway. They will ask questions designed to work out whether the blocked pipe is public or part of your own system, and if they cannot tell from the answers they will visit to find out. 4
Road gullies are a different chain of command again: GOV.UK sends blocked public drains and street drainage to your local council. 5
Once you have established that a pipe is yours, the next question is usually whether you have to pay for it out of pocket. Buildings insurance commonly includes the cost of replacing items such as pipes, cables and drains, which is why a collapsed private drain is worth a call to your insurer before it is worth a call to anyone else. 9
What we will not do is tell you what your policy says, because policies differ and the wording is what decides it. Three questions are worth asking your insurer, in this order:
That last one is the practical reason a survey is usually the first thing to book on a drain that keeps blocking: a dated report showing what is actually wrong is what an insurer, a conveyancer or a neighbour’s solicitor will ask for. How our CCTV drain surveys work.
It depends on which pipe is blocked, not on who noticed it. In most cases, pipework inside your boundary that serves only your building is yours to maintain. A blocked sewer is a different matter: the stretch running from your boundary to the public sewer — the lateral drain — is usually your water company’s, as is any pipe that serves more than one property. Road gullies are usually the council’s. Confirm the position with your water company before you pay for work.
Usually the water company. A pipe that drains more than one building is a sewer rather than a drain, and almost all private sewers and lateral drains that connected to the public network before 1 July 2011 were transferred to the water companies on 1 October 2011. Pipework laid after the transfer and never adopted can still be private and shared between the owners it serves, so check with your water company if the development is newer.
Ownership of most private sewers and lateral drains in England and Wales moved to the regulated water and sewerage companies. The transfer covered pipework that communicated with the public sewer as at 1 July 2011 and took effect on 1 October 2011. In practice it means many shared runs and boundary-to-sewer stretches that homeowners once paid to maintain are no longer theirs.
Where the problem is on the property side of the system, it usually falls to the landlord. For most tenancies granted for a term of under seven years, the Landlord and Tenant Act 1985 requires the landlord to keep the structure and exterior of the dwelling in repair, and it names drains explicitly. That duty does not extend to works the tenant is liable for by virtue of their duty to use the premises in a tenant-like manner, so a blockage the tenant caused is commonly recoverable from them. Tenants should report the problem to the landlord or agent in writing rather than instructing a contractor themselves.
It depends entirely on your policy wording, so this is a question for your insurer rather than one we can answer for you. Buildings insurance commonly includes the cost of replacing items such as pipes, cables and drains. Before you commit to work, ask your insurer three things: whether the policy covers damage to underground pipes serving the property, whether it covers clearing a blockage as well as repairing damage, and whether they need a CCTV survey report before they will consider a claim.
For a blocked public drain or road gully, GOV.UK directs you to your local council. For a blocked public sewer, or a lateral drain beyond your boundary, contact your water and sewerage company, which is responsible for clearing blockages in the sewers it maintains. For a private drain inside your boundary that serves only your building, you appoint a drainage contractor yourself.
Every legal or regulatory statement on this page comes from one of these. Where the position genuinely varies — unadopted pipework, private roads, lease terms — we say so rather than inventing a rule.
Last reviewed 26 July 2026. This page covers England and Wales; the position in Scotland and Northern Ireland differs. It is general guidance, not legal advice.
Once you know whose pipe it is, the next question is usually what it costs. Our drain unblocking cost guide sets out what the common jobs actually cost and what moves the price — useful for sanity-checking any quote, including someone else’s. If the drain keeps blocking, a CCTV drain survey is what tells you whether you need a clear or a repair, and produces the dated report insurers and conveyancers ask for.