CONTACT US: 020 7419 5119

Build over a Sewer and Sewer Diversion Applications

Build over a Sewer and Sewer Diversion Applications

Build over a Sewer and Sewer Diversion Applications”]If you are planning a new development, an extension to a property, building a garage or conservatory then you will need to consider whether there is a public sewer in the way. If your plans cannot be altered then the drainage undertaker may agree to a diversion of the public sewer and will advise whether this would constitute a major or minor diversion. If alteration of the development plans and sewer diversion are not possible, and it is necessary to build over or near a public sewer then it is necessary to agree protection measures with the drainage undertaker before works commence. Although the requirements of different drainage undertakers vary, and no two applications are the same, typically it is necessary to submit the following detail to allow proper assessment of the proposal;

  • Applications to build over or divert a public sewer require supporting evidence, drawings and documentation which usually includes;
  • Location plan.
  • Site layout plan, showing position of building work relative to the existing and proposed sewers.
  • Design drawings including a plan and section showing the position of your proposed works and foundations relative to the public sewer.
  • Cover and invert levels, pipe material details and gradients.
  • CCTV survey report and DVD. This must identify any existing connections along the length to be diverted or built over.
  • Third party details if the sewer is proposed to be laid or connected off site.
  • Any other relevant information.

Both sewer diversion and build over applications can be difficult to agree and may require substantial consultation with the drainage undertaker to achieve a favourable outcome. Our clients find time and again that outsourcing the submission and management of both sewer diversion and build over applications is an efficient use of resources which saves them considerable amounts of time which may be better used elsewhere.

Do need to submit a build over sewer or sewer diversion application? Contact Us!

Speak to our Flood Risk Engineers without obligation now.

Our Flood Risk Engineers are fully qualified, offering expert advice and assistance throughout the Flood Risk Assessment process.


We offer Flood Risk Assessment and Surface Water Drainage services. This is including Sur 1 and Sur 2 Code for Sustainable Homes Asssesments. This covers all types and scales of development throughout the UK where flood risk and surface water drainage information is requested by the Local Planning Authority.


Flood Risk Assessments
Surface Water and foulwater strategy and design
Code for sustainable homes sur 1 and sur 2
BREEAM pol3 and pol 5
Basement impact assessments
Sewer diversion and build-over applications
Flood Defence consent applications
Sequential and exception test reports