The council has nothing to do with a blocked drain. That’s a common misconception. It isn’t how it actually works. Responsibility comes down to one question: does the blockage sit in pipework serving only your property, or in a shared sewer?
Specifically, if it’s on your side, it’s yours to sort and pay for. If it’s shared, it’s Southern Water’s job instead. They’re the statutory sewerage undertaker for Southampton and the wider Hampshire area.
It’s one of the most common questions we hear about blocked drains: is this down to me, or someone else? It’s an easy assumption to make. Surely the council must be involved somewhere? Councils handle so much else connected to a property — bins, planning, the road outside. Drainage, though, isn’t one of them.
Because the answer decides who pays, the rest of this guide shows you how to tell which side of that line your blockage falls on. It also covers what to do next either way.
Private drains vs shared sewers — what’s the difference?
A private drain is the pipework that serves only your property. It covers your toilets, sinks, baths and internal waste pipes. It runs out through the garden or under the drive. It joins a wider sewer at some point. In most cases, that joining point is at or close to your boundary. Anything on your side of it is yours to maintain and pay to clear.
Once pipework starts serving two or more properties, responsibility usually shifts. A shared run that several houses drain into is known as a lateral drain. Since 1 October 2011, most private sewers and lateral drains transferred to new ownership. The local water and sewerage company took over under changes to UK law. That’s why many “shared drain between neighbours” problems are actually Southern Water’s. The 2011 transfer moved that pipework out of private hands.
Put simply: if it’s just your pipe, it’s your problem. If it’s shared with a neighbour, it’s very likely Southern Water’s instead. The same applies if it forms part of the wider sewer network. It isn’t something to negotiate with the house next door. And it isn’t something the council has any part in.
How to tell which applies to you
In practice, most people can make a reasonable first guess before anyone even attends:
- A blocked toilet, sink, bath or shower that backs up inside the house is almost always your responsibility. The same is true of a blockage in the pipe run between your property and the boundary.
- A blockage further out is more likely to sit in shared or public pipework. This is particularly true near or beyond a manhole cover that clearly serves more than one property. It’s also true where your neighbour’s waste seems to join the same run.
- If the nearest manhole cover is running full or backed up, that’s another sign. This applies especially if it plainly serves more than just your house — it’s not just yours to deal with.
None of this replaces having it properly assessed, since guessing wrong costs you either way. Assume it’s Southern Water’s when it’s actually yours, and the blockage just sits there getting worse. You’ll be waiting for a call-out that was never coming. Assume it’s yours instead, and you risk paying for work on a pipe that was never your responsibility. It’s worth having looked at properly rather than guessed at.
What if it’s a public sewer?
If it turns out the blockage is in a shared or public sewer, the right call is Southern Water directly. They’re responsible for clearing and maintaining that pipework, not the council. Report it to Southern Water’s blocked sewer team. Because it’s their pipework, there’s no charge to you for them to clear it.
It’s worth repeating, since it trips so many people up: the council has no role in drain blockages, full stop. It’s an easy mistake to make. Councils handle so much else connected to a property, after all. Drainage responsibility, however, sits with either you or your water company. It’s never the local authority. If you do contact the council about it, expect to be redirected straight to Southern Water anyway.
Frequently asked questions
Do I need to pay if the blockage turns out to be Southern Water’s? No. This applies if it’s confirmed to be in their section of pipework — a shared lateral drain or the public sewer. Clearing it is their responsibility, not yours. There’s no charge to you for them to fix it.
What if my neighbour’s drain is blocking mine? It’s worth checking before assuming it’s a dispute between neighbours. Shared lateral drains that join before reaching the public sewer are often now Southern Water’s responsibility. This follows the 2011 transfer of private sewers to water companies. So what looks like a neighbour problem may not be either of your responsibilities to fix.
Can I unblock a toilet or sink myself first? Often, yes, for simple blockages. A plunger or a sink auger clears many everyday blockages in toilets, sinks and baths. Our blocked drains & toilets page covers what’s worth trying yourself first. It also covers when to stop and get it looked at properly.
Still not sure which side of the line your blockage falls on? Get in touch through our contact form. We’ll help you work it out before anyone starts work. The same goes if you already know it’s yours and just want it sorted. For the household blockages we clear ourselves, see our blocked drains & toilets page. That covers everything from blocked toilets to slow-draining sinks and baths. This responsibility question comes up just as often in older parts of Southampton. It’s common too in nearby towns with plenty of period housing, like Winchester. Our Winchester emergency plumber page covers the same issue for that area’s older drainage. We handle the same drainage disputes in Chandler’s Ford homes and Hythe properties too. Not sure whether it’s a drain issue at all? Our radiator leak guide and our boiler leak guide cover two other sources of water. Both can look similar from the outside.