If a drain serves only your property, it is your job to look after it. If it serves more than one property, Thames Water is responsible. That one rule, set by the October 2011 private sewer transfer, settles most London drain disputes. Still, the line between private and shared is not always where you expect it.
The Basic Rule: Private vs. Public
The key split is between private drains and public sewers.
- Private drain: The pipes that serve your property alone. You maintain and repair them.
- Public sewer: Pipes that serve more than one property. Thames Water looks after them.
For most London terraces, your duty ends at the edge of your plot, although sometimes it ends where your drain meets the shared pipe. In practice, though, the boundary is rarely that tidy.
The 2011 Change: Private Sewers Transfer
In October 2011, the government moved private sewers and some lateral drains from homeowners to the water companies. It affected millions of homes, because before that date, neighbours who shared a drain were jointly responsible for it, and disputes over who should pay were common.
The transfer covers sewers shared by two or more properties, and lateral drains outside your boundary. However, the pipe inside your boundary stays yours. If you paid for a shared drain repair after 2011, you may be able to ask Thames Water about a refund, so check your records.
Mapping Your Drainage
Because you need to know where your duty ends, get a drainage plan. Thames Water runs a sewer records service, and you can request your property's records from them. The plan shows where the public sewers run in relation to your home.
Sewer records are not always right, though. Older London homes have often had their drains altered over the years. If you are buying, a CCTV survey plus a drainage search is the most reliable way to learn the layout, since it also shows any defects before you exchange contracts.
When Thames Water Won't Act
Thames Water must deal with faults in public sewers, yet it can be slow on non-urgent jobs. A typical report goes like this.
- You report the blockage to Thames Water.
- They arrange an inspection, which can take several days.
- They decide whether the fault is on public or private pipework.
- They book repair work if it is theirs.
This can take weeks. Because of the delay, many owners hire a private drain firm to clear the blockage straight away. They then ask Thames Water for the cost if the fault turns out to be in the public pipe.
Practical Advice
Keep a written record of every report you make, with dates and reference numbers, because it helps your case. If Thames Water delays without good reason, you may be able to claim compensation under the Guaranteed Standards Scheme.
When the fault is clearly on your own pipe, act fast, since a blocked drain left alone can flood the house and damage walls. It can also undermine foundations, which costs far more than the original blockage.
Frequently Asked Questions
Who is responsible for the drain between my house and next door?
Since October 2011, a drain that serves more than one property has been Thames Water's job, so if the blockage is in the shared section, contact Thames Water first.
Thames Water says the blockage is on my side. How do I check?
Ask them to share their CCTV footage and the boundary details. However, if you disagree, we can run an independent CCTV survey. The report shows exactly where the blockage sits in relation to the boundary.
I paid to fix a shared drain since 2011. Can I get a refund?
If the drain is shared and Thames Water has since confirmed it as theirs, you may be able to claim, so contact Thames Water directly, or ask a drainage solicitor for advice.
Does my home insurance cover drain blockages?
Some policies include drain cover, usually for private drains only, so check your documents for "drain" or "underground services". Many insurers ask for a CCTV report before they pay a claim.
Can I request help with an emergency drain blockage in London?
We cover all 32 London boroughs. Request a quote online via our contact form.
Because every property is different, start with our guides to blocked drains and drainage investigation advice. We also cover blocked drains in London and blocked drains in Sidcup, so you can see how the work runs near you.
