Concerns on the spiralling costs of South East Strategic Reservoir Option (SESRO) expressed at October Council meeting
Published Tuesday 28 October 2025
Significant public concerns around Thames Water’s South East Strategic Reservoir Option (SESRO) and the spiralling costs now associated with the proposed development, were raised at Vale of White Horse District Council’s meeting on Wednesday 22 October.
Councillors heard impassioned public statements from residents and local representatives before considering a motion on the South East Strategic Reservoir Option (SESRO) and discussed, amongst other issues, the emergence of much higher costs for the development. Capital construction costs have increased so far from an estimated £2.2 billion to three times that amount. Council unanimously approved the motion.
The Leader will now request that The Secretary of State directs Thames Water to prepare a new Water Resource Management Plan in the light of the significant change in costs, alongside writing to all the MPs representing parts of the Vale of the White Horse urging them to support the request. The council will continue arguing for the consideration of the alternative scheme, the Severn to Thames Transfer.
In her Leader’s statement, Cllr Bethia Thomas, expressed her deep concerns for the reservoir. She said: “Tonight’s motion, brought to us in a cross party proposal, voices our strong concerns – not just for the reservoir, the supposed need for it and the potential damage it will have on our district – but for the hugely inflated costs that we are now seeing come out of this proposal – costs that have escalated and are already spiralling out of control, with increases in capital construction costs from an estimated £2.2 billion to three times that amount, and this I am sure is not the last of it.”
The council has previously, on numerous occasions, urged water providers to explore all the alternative and more cost-effective solutions seriously before committing to the reservoir.
Back in August 2025, after having written to Secretary of State in July, Cllr Thomas had expressed her deep concerns: “Water suppliers should instead be focusing on fast-tracking less disruptive alternatives by fixing leaks, educating us all to reduce our water consumption and by exploring the use of water transfers.
“Many concerns remain around the size of the proposed scheme, its environmental impact and significant (growing) financial and carbon costs, as well as the potential for increased flood risk in local watercourses.
“We remain opposed to this proposal, and we will continue to urge water providers, regulators and government to listen to local voices and reject these plans. We will continue to do everything we can within our power to ensure that the voice of our community is listened to.”
All the details on the council’s response and correspondence relating to SESRO is available on the council’s dedicated SESRO webpage.
