Thames Water issues £5.7bn tender for Abingdon reservoir contractor

(by Karma Loveday)

Thames Water has issued a £5.7bn tender for a Main Works Contractor for its newly renamed White Horse Reservoir in Abingdon, Oxfordshire – formerly known as SESRO.

The contractor will design, plan and build the new facility that will supply water locally and onwards to London and Hampshire, including excavation, building embankments and laying pipelines.

Thames is hosting an online applicant briefing on 11 February. Interested organisations have until 24 April 2026 to submit a request to participate, after which shortlisted applicants will be invited to submit detailed tenders.

Initially, the Main Works Contractor will work directly with Thames Water during the design and planning phase, helping to refine the construction designs within the constraints of the Development Consent Order. Because the reservoir is being built under the Specified Infrastructure Projects Regulations, Thames will appoint an Infrastructure Provider to finance the construction and this IP will become the Main Works Contractor’s client at that stage.

Mohit Farmah, head of procurement & supply chain at Thames, said: “We're seeking a contractor with the vision, capability and track record to deliver one of the UK's most significant infrastructure projects, ensuring value for money for our customers. This is project would secure water supply for millions, protect the environment and create a space that people can enjoy for generations to come.”

The reservoir work is expected to generate around 1,800 jobs, from apprenticeships to skilled trades, and including ecologists, geologists, archaeologists, engineers, electricians, construction managers, park rangers and sailing instructors.