Water and wastewater capacity
Following our proposed charging rules consultation last autumn, from 1 April 2025, we have re-introduced charges for our pre-planning enquiry process.
Both waste and clean water pre-planning applications require an upfront fee before we can investigate any network capacity issues for your proposed development. View our charging arrangements document for more details.
If you’re a developer or land promoter considering a new site for development, we can help you with your pre-planning enquiries. The earlier we start talking, the better as you’ll need to know early on if our network for water and/or wastewater has the capacity to serve your development and what we’ll do if they don’t.
You can use this as evidence to support a planning application and we can prepare to serve the new development at the point of need to help avoid any delays to your programme.
Why make a pre-planning enquiry?
We’d advise you to make a pre-planning enquiry as there are benefits for you in doing so:
- Fast answers — we’ll confirm whether we’ve network capacity within three weeks, and what happens if we don’t.
- Avoid delays — if we don’t have the capacity, we’ll discuss a plan of action and timelines with you.
- Planning evidence —we’ll issue a letter you can use to support your planning application.
- Key contact — we’ll provide you with a named contact and their direct telephone number.
How to apply
Before you apply, check your site is within the area we cover.
Download the application form below, and return it to us by email or post to:
Thames Water
Developer Services
Clearwater Court
Vastern Road
Reading
RG1 8DB
Our risk assessment for odour encroachment
Our sewage treatment works and other wastewater sites like pumping stations and storm tanks can sometimes be odour sources. We’ve put together the guidance below to ensure all proposed developments near these sites are risk assessed and, where necessary, that developers fund any mitigation needed to enable them to build there.