Private sector housing

Drainage - help and advice

Blocked household drains are inconvenient and can be a potential health hazard. Drain blockages are preventable.  The council is not responsible for the drainage within the borough

What causes drain blockages?

Common causes include:

  • pouring cooking fat, oils and grease down drains - these can solidify into the waste system and are difficult to remove.
  • detergent scaling, particularly in hard water areas
  • flushing paper and cloth products such as disposable nappies, sanitary towels, cotton wool buds and newspapers down toilets - they can form a solid mass and eventually stop the flow of water.
  • pouring cement and plaster down drains - these can set rock hard in the drain
  • pouring waste oil from motor vehicles into drains - also, it is illegal to do so
  • collapsed or damaged pipes.

Who is responsible when a defect or blockage occurs?

For houses built before 1 October 1937 all pipework serving more than one property will normally be a public sewer maintainable by Thames Water.

From October 2011 Thames Water took ownership and responsibility for maintaining and clearing all private sewers (below ground shared drains).  Thames Water have also taken on the responsibility for some private drains but only when they pass beyond the boundary of the owners property.

Thames Water will also be able to offer a drain clearing service (chargeable) for individuals with a blocked private drain. This service is available 24 hours, 365 days a year.

You can contact Thames Water on 0800 316 9800

Alternatively, you can select a specialist contractor from the telephone directory. Be sure to enquire about hourly rates and call out charges as these can be expensive, particularly at weekends.

The council may become involved with blocked drains if households, being served by a private drain, are unable adequately to deal with the problem. In these cases we are able to use enforcement powers to clear drains and carry out any repairs.