It's nobody's favourite scenario, there's a blocked drain and you aren't sure who's responsible for it. There are three possible outcomes to this one, depending on whether the blockage is a drain, a private sewer or a blocked public sewer. There are actually strict definitions of all three, according to Public Health law, so hold your nose and try and establish which one is your issue.

What is a Drain?

A drain is simply a pipe that only takes drainage from a building or buildings within the same property boundary. It might be a drain for foul water like toilet waste or for surface water such as rainwater from the roof, but whichever it is, if it's on your property, you are responsible for unblocking or repairing it until the point where it reaches someone else's property.

What is a Sewer?

A pipe becomes a sewer at the point where it takes drainage water from the private drains(and then lateral drains) groups of properties.

When it comes to any problems, the law generally requires owners or occupiers of the properties that use and connect to the sewer to repair any damage and remove any blockage that occur in drains within their own property boundary.

Your local Water Company is responsible for clearing blockages, maintaining and repairing public sewers. Before a 2011 law change, some groups of properties were connected to what were called private sewers, and the owners in that group of properties were responsible for the upkeep (including blockages) of those sewers. Since the law changed you are now only responsible for maintaining and clearing drains within your own property boundary.

How do I Know Who is Responsible?

Since the law changed, it has become clearer and generally works as follows:

  • Detached homes - Before 2011 you were responsible for maintaining drains up to the point where they met the main sewer pipe. This meant you may have been responsible for the drains under the pavement and possible part of the road outside your home. Since 2011, you are responsible for the drain only up to the point of your property boundary e.g end of your drive/front garden.

  • Semi-detached homes - Before the changes you and your attached neighbour were responsible for the drain up to the point where it met the main sewer (often under the road outside your properties). Since the 2011 changes, you are responsible only for the part up to your boundary with the adjoining house. If the drain runs across your property from your neighbour's before continuing towards the sewer then your responsibility ends at their boundary (the water company is responsible for the remaining part across your property), so even though that part of the drain is within your property boundaries you are not responsible for it.

  • Terraced houses - Before the changes in 2011, each home was responsible for any part of the drain that crossed their property boundary before it reached the sewer. Since the change, you are only responsible for the part immediately before it connects to the drains of the other terraces in the row. So if the drain runs from one end of a row of terraces to the other you only need be responsible for the part of your drain before it connects to it (the water company is responsible for the rest of the drain).

Other Privately Owned Sewers

Some properties, particularly those in rural areas do not connect directly to a public sewer, those with a cesspit, septic tank or treatment plant have not been affected by the law changes and will normally have their own arrangements for blocked drains and maintenance.

Private Pumping Stations?

Since the phased changes were completed, water companies are now (in general) responsible for maintaining private pumping stations and the pipe work that were previously the responsibility of property owners.

Blocked Sewer or Drain?

If you think there is a problem with a blocked sewer, contact your local water company. If they discover the blockage is actually within your drain (the part for which you are responsible), then you will have to take steps to clear the blockage yourself.

If Neighbours are Uncooperative over a Blocked Drain

Most drain un-blocking companies will invoice the person who called them out, no matter who is actually responsible in law for covering the costs. If you live in a terrace or semi detached home for example and discover the blockage is due to a neighbouring drain then you will have to approach them for payment. Your local council has powers to serve legal notices on anyone who fail clear a blockage under various Public Health acts.

What About Guttering?

Shared land also means shared responsibility for repair, and so if there are damaged gutters, it's reasonable to share the costs of repairing them. If guttering and water egress drainage is shared between two properties (look at your deeds and it should say whether this is the case) there is normally a joint responsibility (and liability) for maintenance and repair.

Talk to your neighbour before you organise anything, once you've checked the deeds to make sure you're in the right. Most neighbours will be reasonable, especially if you have the deeds to back you up, and a polite request should be all you need. If they refuse, you have no choice but to get the work done and then request reimbursement of their share in writing. If they still won't play ball, you'll have to get down to the county court, but the law is certainly on your side…