Thames Water has put forward revised proposals for a large-scale water storage facility in the vicinity of Abingdon, introducing additional access provisions and opening a fresh round of public engagement.
The White Horse water storage project would hold 150 billion litres of water across a surface area of 6.7 square kilometres, roughly comparable in scale to Gatwick Airport.
Following a review process, projected expenditure has risen dramatically from an initial £2.2 billion to somewhere between £5.5 billion and £7.5 billion.
The site footprint has expanded to 38 square kilometres to facilitate additional construction requirements, the relocation of nearby solar installations and the redirection of local watercourses.
According to Thames Water, the initiative requires supplementary access routes to facilitate construction activities and environmental improvement measures, including the establishment of new wildlife habitats.
This necessity has prompted targeted engagement with affected landowners and other parties with interests in the land potentially affected by these modifications.
In recent weeks, the utility company emphasised that the proposed reservoir would prove essential given escalating temperatures.
An initial public consultation on the scheme concluded during January.
A subsequent consultation period commenced recently and is anticipated to run until the following month.
Thames Water intends to file its planning submission by the end of 2026.
Subject to planning consent, principal construction operations would commence in 2032, with water supplies becoming accessible by 2040.
The project would ultimately supply approximately 15 million individuals.
Thames Water maintains that the reservoir is necessary to address demographic growth in the south-eastern region and the effects of climate change, which have intensified strain on water supplies throughout numerous areas of the United Kingdom, including during the exceptional heat conditions experienced during the recent summer.
Consumers supplied by Thames Water, Affinity Water and Southern Water are anticipated to finance the reservoir through their water bills across the next century.
Local authorities in the Vale of White Horse district, alongside Abingdon town council and Oxfordshire County Council, have voiced opposition to the scheme.
Their objections centre on flood hazards that could affect surrounding communities arising from the watercourses requiring diversion to accommodate the reservoir.
Derek Stork, who chairs the Group Against Reservoir Development, argued that the reservoir concept is fundamentally problematic and that more ecologically sound approaches to regional water provision exist.
He contended that Thames Water has not conducted satisfactory consultation with community organisations, local authorities and residents.
According to Stork, no analysis of dam failure scenarios or comprehensive flood modelling has been disclosed, notwithstanding the reservoir’s positioning within an area classified as having the highest flood risk and the possibility of devastating outcomes should structural failure occur.
Leonie Dubois, delivery director responsible for consents and place at Thames Water, stated that following the United Kingdom’s warmest summer on record, investment in future water supplies is imperative.
She expressed confidence that the reservoir represents the most cost-effective solution for guaranteeing water supplies for 15 million individuals across the south-eastern region, encompassing customers of all three water companies involved.
Dubois noted that the current targeted consultation represents merely the most recent component of an ongoing engagement programme spanning more than four years.
She explained that responses gathered during this process, alongside feedback obtained during the formal public consultation held previously, would inform the evolving proposals.
The reservoir also presents a significant opportunity for local communities, with recent research indicating that 89 percent of south-eastern residents endorse the scheme.
Dubois elaborated that the facility would offer recreational possibilities for visitors, including walking, cycling and sailing opportunities.
Natural habitats, wetland areas and woodland would be established throughout the site, while the clay embankments would incorporate varied gradients and gentle slopes to integrate naturally with the Oxfordshire countryside.
The United Kingdom maintains an exemplary record regarding reservoir safety, and the proposed Oxfordshire facility would comply with stringent criteria established under the Reservoirs Act 1975.
Design, construction and ongoing operation would all fall under the Act’s regulatory framework.