When a drain blocks in Southampton, it is worth spending two minutes working out whose problem it is before you pay anyone. Southern Water is responsible for public sewers across the city, and for many shared drains too. Your responsibility is usually limited to the pipes serving only your property.
Step 1: Check what is affected
- One sink, bath or toilet is slow, and everything else is fine: the blockage is almost certainly in that fitting’s waste pipe, inside your property. This is yours to deal with.
- Several fittings are backing up, especially downstairs: the blockage is further down, in the underground drain. Keep going.
Step 2: Ask your neighbours
In Southampton’s terraced streets, such as those in Shirley, Portswood, Freemantle and St Denys, drains are often shared along the back of the houses.
- Neighbours are having problems too: the blockage is likely to be in a shared pipe or public sewer. This usually means Southern Water.
- Only your property is affected: the blockage is more likely to be on your private drain.
Step 3: Look in the inspection chambers
If you can safely lift the covers on your property:
- Your chamber is full, and the one downstream (towards the road or the rear boundary) is empty: the blockage is between them, usually on your drain.
- The last chamber before your boundary is full: the blockage may be beyond your boundary, in the lateral drain or sewer.
- A chamber serves pipes coming from next door: that chamber is part of a shared system.
Do not lift heavy, cracked or seized covers, and never climb into a chamber.
Step 4: Decide who to call
- Probably Southern Water’s responsibility: report it to Southern Water through southernwater.co.uk or their customer service line. Tell them it is a sewer blockage and whether sewage is escaping.
- Probably yours, or you are not sure: call a drainage company. A good one will check the chambers first and tell you straight away if the problem is Southern Water’s, rather than charging you to clear a sewer you do not own.
What about Eastleigh, Totton and further afield?
Southern Water provides sewerage across most of Hampshire, including Eastleigh, Totton, Romsey, Winchester, Fareham and Portsmouth. In Bournemouth, Poole, Christchurch and Salisbury, the sewerage company is Wessex Water. The same principles apply: private drains are yours, shared sewers connected to the public network are usually the water company’s.
If sewage is escaping
If sewage is coming up through a toilet, shower or outside drain, stop using water in the property and keep people and pets away. Read what to do if a drain overflows. If the blockage turns out to be on your drain, we are open 24/7 for emergency drain unblocking in Southampton.
For more on the rules, see who is responsible for a shared drain.