We brought together leading contractors and investors for our early market engagement event, marking a crucial milestone as our reservoir plans become a reality.

Water resources in the South East are under increasing pressure. Our population is growing, and we continue to experience more extreme weather, both of which bring unique challenges. We're developing plans for a new reservoir near Abingdon in Oxfordshire, known as the South East Strategic Reservoir Option (SESRO), to protect the environment and secure future water supply.

The proposed new reservoir will have a capacity of 150 billion litres and a surface area of approximately seven square kilometers. It will be one of the largest in the UK, providing water resilience to customers across the South East, including customers served by Thames Water, Affinity Water, and Southern Water.

On Monday 17 March, we brought together over 100 leading contractors and investors for our early market engagement event, marking a crucial milestone as our reservoir plans become a reality. For contractors and investors, it represents a unique opportunity to play a key role in developing nationally significant infrastructure that will secure water supply for 15 million people across the region and a project that is essential for society as a whole.

Why did we engage the market at such an early stage?

Engaging the market early has many benefits, including preparing potential partners so they can understand our vision and priorities, and effectively plan to respond to our needs. We also listen to feedback to refine and optimise our proposed delivery approaches.

Ultimately, these actions will help us secure the right partnerships and people to deliver the best value for our customers while also serving communities and the environment. Our potential suppliers and investors will contribute essential expertise to this project with distinct yet complementary roles.

The Main Works Contractor

Overall, we're looking for a supplier who has a strong track record of delivering major infrastructure projects, can work collaboratively, and provides us with the most advantageous offer. The Main Works Contractor (MWC) will be the hands-on builder of the new reservoir, effectively designing and planning construction, from excavation to building embankments and laying pipelines. Initially working directly with Thames Water during the design and planning phase, they'll help refine construction designs within Development Consent Order process constraints and fully plan construction before breaking ground under the Infrastructure Provider.

The Infrastructure Provider

The Infrastructure Provider (IP) will finance the project and establish itself as a separate licensed entity that will own and operate the reservoir for decades. Upon appointment, the IP will ultimately assume delivery control from Thames Water and take over and manage the contract with the Main Works Contractor (MWC). This approach spreads the costs of delivering the new reservoir over a longer timeframe, creating greater value for customers.

Kick-starting conversations

One of our primary goals in engaging the market at this early stage is to kick start conversations between contractors and investors. By bringing both markets together simultaneously, we're facilitating crucial understanding between these future partners before they formally join forces.

This collaborative approach helps align strategic interests and expectations when the Infrastructure Provider eventually takes ownership and assumes responsibility for the Main Works Contractor relationship, effectively de-risking the marriage between the two as they work to support us in delivering water security for millions.

Moving forward

Following our continued early market engagement efforts, we're entering a critical procurement and commercial strategy phase. We'll be working with potential partners to hold 1-2-1 discussions and gathering detailed questionnaire responses from construction contractors and potential investors. This dual approach will enable us to understand the market's capabilities and insights comprehensively. In the autumn, we'll launch the official procurement process for the MWC via the Find a Tender service (FTS), the central digital platform for public procurement. We will notify the market of our requirements and invite formal expressions of interest.

Want to know more?

Whether you are a supplier or potential investor, if you have questions about this procurement process and our reservoir, please get in touch with our market engagement team at SROsupplychain@thameswater.co.uk

Mohit Farmah, Head of Procurement, Supply Chain & Digital for the Strategic Resource Options at Thames Water.