Information about building over a public sewer

There are different names for the pipes commonly used to discharge foul and storm water from buildings:

  • private drain - a drain serving a single premises
  • private sewer - a drain serving two or more premises
  • public sewer - a drain serving two or more premises owned or adopted by the sewerage undertaker (Severn Trent Water Limited)

The vast majority of private drains and sewers will discharge into a public sewer. In certain circumstances what might initially appear to be a private sewer may in fact be a public sewer.

Public sewers within Cheltenham borough are managed by Severn Trent Water Limited.

The majority of public sewers run under public roads, however in some instances they can be found to cross private land. If the sewer to your property was built before October 1937 then it is also considered to be a public sewer under the provisions of Section 24, of the Public Health Act 1936.

If you think that the sewer serving your home might be a Section 24 or adopted public sewer then you should clarify the matter with Severn Trent Water Limited who will be able to provide you with a definitive answer.

Building requirements

When building over or within 3 metres of a public sewer the Approved Document to Regulation H4 (Building Over Sewers) of the Building Regulations 2000 clarifies that:
  • you must consult with the sewerage undertaker (Severn Trent Water Limited)
  • you must take steps to prevent any undue risk to the building in the event of a failure of a drain or sewer
  • access to the drain or sewer must be maintained externally to any building or extension at all times
  • the drain or sewer must be adequatly protected during construction
  • you must take steps to protect the drain or sewer from any settlement

For further information please refer to approved document H of the Building Regulations 2000.

Building regulations submission

Making a building regulation submission where building over or within 3 meters of a public sewer up to 225 millimetres in diameter will require a full plans submission under the regulations. In these circumstances a Building Notice cannot be accepted. It is advisable that you obtain consent first from Severn Trent Water before you make your application to the local authority.

As part of the process, the building control team has to consult Severn Trent Water. Your application will only be approved if the works comply with the requirements of Part H4. The Part H4 regulation protects both your works and the public sewer. In some cases the building control officer will require proof of Severn Trent consent before approving your application.

In addition to building control officer approval, you will need formal approval from Severn Trent Water. Failure to obtain this would not only be illegal but could also jeopardise the future sale of your property.

How do I know if a public sewer is affected?

Information on the location of the public sewers can be obtained from Severn Trent Waters records management centre by telephone on 0121 452 3313. A copy is also available at the council offices and is available for inspection upon request; however, copies or photographs of these cannot be taken and these are not as concise as the records held by Severn Trent.

If a public sewer could be affected by proposed building works, it is advisable to obtain consent from Severn Trent Water before making a building regulations application. This will avoid delay in the full plans approval process.

Further advice and an application form can be obtained from Severn Trent Water.