If your drain is blocked and your neighbours are affected too, the first question is not how to fix it but whose problem it is. In England, the answer depends on what kind of pipe is blocked and where it is.
The short answer
- Your private drain is the pipe that carries waste from your property only, up to your property boundary. You are responsible for it.
- A shared sewer is a pipe that carries waste from more than one property. If it connects to the public sewer network, it is usually the water company’s responsibility, even if it runs through your garden.
- A lateral drain is the section of your own drain that runs outside your boundary, often under the pavement or road, to reach the sewer. This is usually the water company’s responsibility.
- The main public sewer, usually under the road, belongs to the water company.
What changed in October 2011
Before 2011, many homeowners were responsible for shared pipes they did not even know about. On 1 October 2011, private sewers and lateral drains that were connected to the public network before 1 July 2011 were transferred to the water companies. In Southampton and most of Hampshire, that is Southern Water.
That is why a shared drain running behind a row of terraced houses is now usually the water company’s responsibility, not the homeowners’.
The exceptions
- Pipes laid after 1 July 2011, for example on newer estates, stay private unless the water company has formally adopted them. Some new developments still have unadopted sewers owned by the developer or a management company.
- Pipes that do not connect to the public sewer, such as those running to a septic tank or cesspit, remain private.
- Pumping stations serving private drains may have different arrangements.
If you are not sure, the water company can tell you whether a pipe is public.
How to tell where a blockage is
Lift the inspection chamber covers on your property, if it is safe to do so, and look at the water level:
- Your chamber is full, but the next one downstream is empty: the blockage is probably between the two, which is often on your private drain.
- The chamber at or near your boundary is full, and neighbours are affected: the blockage may be in a shared sewer or lateral drain, which is likely to be the water company’s responsibility.
- You cannot tell, or cannot lift the covers: a drainage engineer can check the chambers and, if needed, use a CCTV camera to find the exact location.
Do not lift heavy or damaged covers yourself, and keep children and pets away from open chambers.
Who pays if it turns out not to be your drain?
If the blockage is in a public sewer or lateral drain, the water company should clear it at no cost to you. Report it to them directly. If you have already called out a drainage company, a good one will tell you as soon as they find the problem is not on your private drain, so you are not paying for work that is someone else’s responsibility.
Help in the Southampton area
We can check your chambers, tell you where the blockage is and whether it is your responsibility, and clear it if it is. See blocked sewers, blocked drains in Southampton, or read our guide to telling whether a blocked drain is Southern Water’s responsibility.