Sewer adoptions

Would you like to offer a newly-constructed or existing sewer, pumping station or wastewater treatment works to be adopted by us as a public sewer or asset? If so, our engineers can guide you through the process, and make sure the assets meet the necessary standards.

Alternatively, a sewer can be offered for adoption to a new appointee and variation, who can also provide wholesale water and/or sewerage services for a defined area. To find out more, visit our new appointment variations (NAV) page.

Codes for adoption

On 1 April 2020, Ofwat introduced a new standard practice across the water industry in England which covers the adoption of newly constructed sewers, pumping stations and wastewater treatment works. The new process is outlined in Water UK’s new Sewer Sector Guidance (SSG) which has now replaced the ‘Sewers for Adoption’ guidance.

The guide below explains what you need to do when offering new sewers, pumping stations or wastewater treatment works for adoption – including links to make an application.

Stage 1a – Pre-planning enquiry

When you begin planning your development, our engineers will work with you to agree your:

  • site drainage strategy
  • points of connection to the wastewater network
  • discharge rates.

Before you complete the application form, please read the wastewater pre-planning guidance. Please also check the water and wastewater asset maps for your site – if you’d like to buy a sewer or water plan from us, please see our sewer and water maps page.

If you’re constructing a large/complex development, you may wish to complete a pre-design assessment. More details can be found under Stage 1b below.

Please note that a pre-design assessment is mandatory where you are designing a wastewater treatment works for construction and adoption; this is due to the complex nature of the design requirements. Through having a pre-design assessment our team of engineers can review your plans with you and ensure that your proposals are satisfactory for adoption prior to your application.

We would also recommend a pre-design assessment for sites where sustainable drainage is planned for construction and adoption. This will allow us the opportunity to work through your plans with you and provide some initial guidance.

For more information, and to complete a Pre-Planning application, please visit our planning your development page.

Stage 1b – Pre-design strategic assessment

For large/complex sites one of our engineers can discuss with you the early stages of your design and proposals for maintaining a sewerage system.

This communication can be requested at any point before the submission of a sewer adoptions application (S104) through a pre-design strategic assessment application.

Whether a site is large or complex can be determined by whether it has:

  • Multiple phases
  • Multiple landowners/customers
  • Multiple points of connection
  • Pumped discharges
  • A storage component
  • A Wastewater Treatment Works
  • Sustainable Drainage System

However, the above list isn’t exhaustive. So you may request a pre-design strategic assessment based on your understanding of a complex element of the development that you want to discuss with us before submitting a sewer adoption application. As advised in Stage 1a, a pre-design assessment is mandatory where you are designing a wastewater treatment works for construction and adoption. 

Please complete the pre-design strategic assessment application form and email it to [email protected]. Before you fill in the application form, please read the wastewater pre-design strategic assessment guidance.

Please read the wastewater pre-design strategic assessment guidance – if you’d like to buy a sewer or water plan from us, please see our sewer and water maps page.

Stage 2 – Design and acceptance of the sewerage system

The Design and Construction Guidance (DCG) is covered under Appendix C of the Sewer Sector Guidance document, which replaced Sewer for Adoption (SFA). The DCG details the new design and construction standards for adoptable foul and surface water systems.

If you want to apply for the adoption of a new sewerage system, you’ll need to apply via our GetConnected portal. The application fee is £650.00 (incl. VAT).

If your design includes offering a pumping station for adoption, you’ll need to refer to our ‘pumping station local practice’ for our design requirements – this is available in our current Pumping Station: Local Practice Guidance. A pumping station will be covered under the same adoption agreement as gravity sewers.

Once we’ve received your completed application – along with the required minimum information – our engineers will complete a technical assessment of your submission and you’ll hear from us within 28 calendar days.

Stage 3 – Adoption Agreement and early start request

When you’ve received your technical acceptance for your sewerage system design from us, you’ll need to enter into an adoption agreement for us to formally adopt the sewers.

To enter into an adoption agreement, you can either ask us to produce one and provide all the required documents – or you can prepare your own legal agreement (this Model Sewer Adoption Agreement may provide a helpful starting point).

We understand construction may need to start before the adoption agreement has been signed by all parties. Once technical acceptance has been given and you have paid the adoption fees, you can complete an early start request to avoid delays to this work.

Once you've completed your request, you can click the email address at the end of the form – the file will automatically set up an email for you to send to us. 

Should you receive conditional technical acceptance and you wish to start the construction of the asset/s subject to that acceptance prior to the scheme receiving full technical acceptance, then you can submit an early start request to us at that stage. 

Stage 4 – Construction of sewerage systems

Before you begin constructing the new sewerage system, you’ll need to complete a pre-start inspection request. Once we’ve received this and all fees have been paid, one of our inspectors will organise a pre-start site meeting for your new development.

While construction of your sewerage system is underway, we’ll carry out inspections to check it complies with the adoption agreement. If we find any defects – such as improper work, materials or variations – we’ll will notify the site contact.

Once the site is over 50% occupied and construction of the sewerage system is finished – including any pumping stations – our inspector will confirm that the system has been inspected, including by CCTV, and all remedial works are complete. Once this has happened, the site can proceed to the maintenance stage.

Stage 5 – Maintenance period and provisional certificate

Once construction of the sewers – along with any outstanding remedial work – has been completed, you’ll need to request a sewer adoption maintenance inspection and provide:

  • The ‘As Built’ drawings
  • The health and safety file
  • Any other outstanding requirements

Please send the request with the above information to [email protected] including the sewerage reference number for your application and site location in the email subject line. Please also mark it for the attention of the Assistant Adoption Manager who has undertaken the inspections of the site to ensure the request is picked up as soon as possible.

We’ll arrange a maintenance inspection to confirm the works are suitable to be placed on ‘12 months maintenance’ and we’ll issue a provisional certificate.

Stage 6 – Final inspection and vesting

Three months before the end of your maintenance period is due, you should check the sewerage system and make sure no maintenance issues are outstanding, then contact your Assistant Adoption Manager. They’ll organise a final inspection of the adoptable system and will advise if any remedial work is required.

Once we’re satisfied all remedial works have been carried out, our engineer will issue the final certificate of completion. The legal vesting of the sewers will happen soon after.


The purpose of this stage is to confirm any variations requested to the design of the sewerage system after technical acceptance has been granted.

If any variations to the system occur, please contact the team at [email protected] in the first instance for further guidance.

Below is general breakdown of how we assess variation:

  • Minor – Can be discussed with us and if acceptable can be recorded on the ‘As Built’ drawings
  • Major – After initial guidance will need to be re-submitted for formal approval.


Local practices

We consulted with our customers on our Pumping Station Local Practice document. We are reviewing your feedback and will publish our responses soon.

If you'd like to provide your feedback, please send us an email with ‘Pumping Station Consultation’ in the subject line to [email protected].

Adoptable Pumping Station: Local Practice Guidance


Adopting existing sewers

Under Section 102 of the Water Industry Act 1991, the owner of an existing private sewer can apply to transfer ownership of their sewer to us.

Our guidance notes for adopting existing sewers sewers provides all of the information you need to offer existing sewers to us for adoption. If you’d like to apply for us to adopt an existing sewer, please use the S102 application form on our online portal.



Section 7 of the sector guidance sets out the process for redress where a level of service metric has not been met by the water company.

We have created a redress document for ease of reference that captures both the redress guidance and link to the associated metrics.

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