Final call: have your say and shape plans for Thames Water's proposed new reservoir

• Thames Water is calling on customers and communities to share feedback on its proposed 150 billion litre reservoir in Oxfordshire.
• The reservoir would be situated southwest of Abingdon and would secure water supply for 15 million people, including Thames Water, Affinity Water and Southern Water customers.
• Since October, the company has welcomed 1,261 people across seven in-person and two online events and has received almost 900 consultation responses.
• There is one more week for the public to share their views before the consultation closes at 11:59pm on 13 January 2026.
• Feedback gathered will inform the company’s Development Consent Order application which it will submit to the government later this year.

The UK’s largest water company is consulting on its plans for a nationally significant reservoir that would secure water supply for 15 million people across the South East, including Thames Water, Affinity Water and Southern Water customers.

The project is an essential part of Thames Water’s strategy to meet future water demand, in response to the effects of climate change, a growing population, and the need to reduce the amount of water taken from precious rivers and chalk streams.

The reservoir would provide up to 271 megalitres of water per day during drought, the equivalent to around 3 million baths. 

Leonie Dubois, Head of Engagement, Land and Consents at Thames Water, said: “Last year was the hottest and sunniest on record. It’s therefore essential that we invest in new infrastructure, and our reservoir represents one of the UK’s most critical projects.

“Not only would the reservoir protect the South East’s water supply, but it would also create a space for nature and place for people. It would be somewhere communities can walk, sail and cycle and can enjoy for years to come.

“With one week to go, we want to hear from as many people as possible. Previous consultation feedback has already helped to shape our designs, so I’d encourage everyone to have their say and feedback on our plans.”

The consultation represents a critical step for the project, with responses helping to shape the Development Consent Order application Thames Water will submit to the Secretary of State later this year. Should consent be granted, water would be available for use from 2040.

Feedback from previous non-statutory consultations has already shaped plans for the reservoir.  The project now includes plans for around 100 km of paths, bridleways, and cycleways connecting local villages as part of the project, along with the introduction of floating solar panels within the reservoir site.

Thames Water is also carrying out a £20bn upgrade across its network, driving down leakage in the process. Over the next five years it will install more than a million smart meters, helping customers to reduce their water usage.

Have your say

The company launched its statutory consultation on Tuesday 28 October 2025 to gather feedback on its reservoir plans, including the project design and opportunities to enhance local spaces.

One week remains for customers, communities and stakeholders to share their feedback, with the consultation closing at 11.59pm on 13 January 2026. 

To find our consultation materials and more information on the project, visit our dedicated consultation website.

How to respond

People can have their say on the project by giving written feedback in one of the following ways:  

• Fill in the online feedback form, which you can find at the consultation website at www.thames-sro.co.uk/sesro/statcon2025  
• Emailing the dedicated consultation response email address at SESRO@ipsos.com  
• Filling in one of the printed feedback forms and posting it free of charge to FREEPOST SESRO CONSULTATION.  

All responses must be received in writing by 11.59pm on Tuesday 13 January 2026.