Defects in drainage systems are a major cause of damage to a property but are often overlooked when buying a house. From 1st October 2011 the responsibility for many pipes connecting people’s toilets, sinks and baths to the public sewers passed to the local water and sewerage companies. There will of course over the next few years be an increase in water bills to cover the cost of maintaining a hugely expanded network.

The common misconception is that this means that all pipes have been publicly adopted and are therefore to be maintained by the water and sewerage companies.

However this is not the case. Public adoption only covers those pipes outside the boundary of your property or pipes which are shared with other properties. If there are pipes within the boundary of your property or pipes which serve your property alone, then these pipes will remain your responsibility.

As many drainage routes are not plotted or their whereabouts are not known, if a blockage or failure occurs then it may be difficult to ascertain if the water company or an individual is responsible. However it is likely that the cost will fall to the homeowner in the first instance as they are directly affected by the defective drains. They may then seek to recover that cost from the water company – easier said than done!

Another issue in addition to the repair obligations of pipes arises if you are planning to extend or rebuild your property or undertake a small development. You will need to bear in mind that at some point in the near future it is likely that water companies will not allow extensions to be built over or within very close proximity to any sewer of or over 225mm in diameter.

In order to ascertain if this affects a property that you are intending to purchase, there are various searches which you can carry out. The standard water and drainage search which conveyancers carry out shows only main public sewer runs and not branch drains, private shared sewers or lateral drains serving the property. Therefore you need to be aware of where the drains are and arrange your own survey to have full knowledge of any future liability and whether your proposed plans for your home improvements are possible. You should also check that your building insurance covers drains that are your responsibility.