Thames Water has invited three consortia to tender for the construction of its proposed new reservoir in Oxfordshire.

The water company says the £5.7bn contract represents the “largest water infrastructure investment in a generation” and would create more than 1,000 jobs during construction.

White Horse Reservoir would secure water supply for 15 million people across the South East, including Thames Water, Affinity Water and Southern Water customers.

Three joint ventures have been invited to tender to become the main works contractor, which would design, build, test and commission the new site near Abingdon.

The invitation to tender marks another major milestone for the project, which once built, would be the second largest reservoir in the UK. It is expected the reservoir will take around a decade to build and two winters to fill, with water available for use from 2040.

The Main Works Contractor shortlist includes three joint ventures:

• WFH JV: comprising of Webuild S.p.A. (JV leader), Hyundai Engineering and Construction Limited and FCC Construccion
• BMV+: Bouygues Travaux Publics (JV leader), J. Murphy & Sons Limited and VolkerFitzpatrick
• BBV: Balfour Beatty Civil Engineering Limited (JV leader) and VINCI Construction Grands Projets S.A.S. 

Simon Adams, White Horse Reservoir programme director at Thames Water, said: “The record breaking hot and dry summer has demonstrated just how critical water storage is to the country, so it’s vital we continue to deliver this project at pace.

“Few projects offer the chance to help secure the country's water future for decades to come, which is why we’ve selected world-class companies who will bid to build White Horse Reservoir. As we move into the next stage of the procurement process, we look forward to seeing bids that match our ambitions for this once in a generation project.”

White Horse Reservoir, formerly known as the South East Strategic Reservoir Option,  is one of nine new reservoirs planned in England and is set to secure water supply for the South East for the next century.

Beyond water storage the reservoir would become a destination and hub for local communities. The construction of the reservoir is set to create more than 1,000 jobs.

Business have launched a White Horse Reservoir Growth Coalition to signify support for the project which will unlock economic growth across the country and bring opportunities for businesses of all sizes right across the supply chain.

The shortlisted organisations are now invited to tender and submit a bid to build White Horse Reservoir in Spring 2027. The main works contractor would build White Horse Reservoir, designing and planning construction, from excavation to building embankments and laying pipelines.

The reservoir would be delivered using the funding model used for the Thames Tideway Tunnel. Thames Water plans to appoint an independent company (infrastructure provider) in 2029, which would be competitively selected to finance the project, and deliver the reservoir together with the main works contractor.