Council Leader calls for authorities intervention over escalating reservoir prices as public session opens

Published Monday 17 November 2025

The Leader of Vale of White Horse District Council, Cllr Bethia Thomas, has written to the Secretary of State for Environment, Food and Rural Affairs, calling for pressing motion on Thames Water’s controversial South East Strategic Reservoir Option (SESRO).  

SESRO would create a reservoir of unprecedented scale in Oxfordshire, close to Abingdon, overlaying as much as 6.7 sq. kilometres and holding 150 billion litres of water. The council has beforehand argued the plans fail to completely think about the long-term impacts to the area people and the atmosphere, each throughout a decade of building and the irreparable injury to the countryside. 

Any reservoir would additionally come on the expense of great carbon emissions which the council argues would affect the district’s capacity to turn out to be carbon impartial by 2045. 

The letter follows a unanimous council vote on 22 October, following a movement on the rising issues across the proposal. The letter outlines the intense issues about spiralling prices, flawed assumptions, and the failure to correctly think about different options. 

When Thames Water’s Water Resources Management Plan was accredited in September 2024, SESRO was costed at £2.7 billion. In its current submission to the regulatory authority, that determine has soared to an astonishing £6.6 billion—greater than double the unique estimate. Cllr Thomas argues this “grotesque understatement” fatally undermines the case for SESRO and calls for a full reassessment of strategic water choices, together with the Severn to Thames Transfer (STT) scheme. 

Cllr Thomas has requested a gathering with the Secretary of State and native MPs to debate these issues and can proceed to press for a public inquiry into SESRO. 

Cllr Bethia Thomas, stated: “This price explosion adjustments every little thing. SESRO was accredited on assumptions that Thames Water itself now admits have been wildly inaccurate. Continuing down this path with no full reassessment can be reckless and will depart taxpayers footing the invoice for a challenge that fails to ship. 

“Our beforehand expressed issues across the security of the proposed reservoir, the related flood threat, and its environmental affect have nonetheless not been adequately addressed.   

“We are calling on the Secretary of State to intervene, direct Thames Water to prepare a new plan with accurate financial modelling, and ensure that alternatives like the Severn Thames Transfer are properly considered. Our residents deserve transparency, accountability, and solutions that protect both their future and our environment.” 

Public Consultation

Thames Water has now launched its statutory public session on SESRO, which runs for 11 weeks from 28 October 2025 to 13 January 2026. Residents are inspired to have their say on the proposals. 

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