Codes for Adoption

Ofwat is introducing a standard practice across the water industry in England for water companies to follow when adopting self-laid mains – Codes for Adoption. This will replace what was previously known as ‘National Codes of Practice’. You can find out more on Ofwat's website.

To underline our commitment to you in line with Ofwat’s Codes for Adoption, we’ve developed a process of redress for the formal adoption of clean water assets.

Our design and construction specification document will help you with the planning, design, construction and commissioning of self-laid mains and service pipes that supply domestic, industrial or commercial properties.

Minimum information requirements

We’ve created this minimum information requirements document to support Ofwat’s Codes for Adoption. This document clarifies the types of plans, design information and documents you should submit to us at each stage of the pre-planning, design and connection processes in line with Ofwat’s approach.

This helps us make sure we have everything we need to process your request as quickly as possible, and by avoiding delays, we can help you keep to your timelines.

Annual contestability summary

The connection activity that is open to competition is known as ‘contestable’ work. This category includes the majority of work a developer needs to serve a new development and includes all work to lay and test new mains and services.

Because we have a responsibility to maintain wholesome water supplies to customers, some higher-risk work may be defined as ‘non-contestable’ and can normally only be carried out by us.

Our annual contestability summary sets out the work that you can do, may be able to do, and work we’ll normally do.

Our model adoption agreement and named contacts

We’ve uploaded our model adoption agreement for you to view or download, and you can see our published named contacts document, which provides details for the relevant Thames Water representatives throughout the self-lay process.

Codes for Adoption forms

Throughout the self-lay process, there’s a few forms you’ll need to complete. For easy access, we’ve listed these forms, however if you’re not sure when or how to complete any of these documents, please contact your account executive or agent who’ll be happy to help.