Dwr Cymru Welsh Water

We’re here to help you when you’re thinking about extending your home.

If you’re planning to extend your property, you’ll need to make sure you know if there are any public sewers or drains on your land.

If there is pipework there it could affect your build, so it’s a good idea to find out before you begin.

If you plan to build over, or within 3 meters of one of our sewer pipes or drains, you’ll need to secure our consent.

To find out more about building over or close to sewers, please refer to our Guidance Notes.

Once you have read our Guidance notes and established that you either need to submit a Declaration of Works or complete an application for Build Over Agreement, please submit as follows:

  • To submit a declaration please either post or email us or,
  • To submit an application for a formal agreement please either post or submit online via the Consent via Formal Agreement button below.

If you would like us to send you a printable version of our guidance notes, please contact us at developer.services@dwrcymru.com or call for a copy on 0800 917 2652