A public inquiry has been called for into plans to build a reservoir the size of Heathrow Airport near Abingdon by 2043.
Vale of White Horse District Council is concerned that Thames Water, which is behind the plan, has not correctly followed procedures in its draft Water Resources Management Plan and has not fully explored each option in sufficient depth.
Council leader Matthew Barber said: “We are yet to be convinced that the proposed reservoir at Abingdon is necessary or indeed the most effective option to address the future water needs of the south east of England.”
The Vale said it wanted to see all of Thames Water’s proposals, including the implications on local residents, roads and the environment.
At 150 million-cubic metres, the proposed reservoir between Steventon and Marcham would be larger than the town of Abingdon.
The plan sets out how Thames Water intends to provide a secure and sustainable supply of water for the next 80 years.
A previous proposal was rejected by the government in 2011, when the then-secretary of state Caroline Spelman said there was ‘no immediate need’.
Cllr Barber, set to step down as leader later this month, said: “The key issue in a previous public inquiry in 2010 into Thames Water’s draft plan, expressed the same concerns and we would still like to see all proposed options fully assessed to the appropriate level of detail.”
Last month, Oxfordshire County Council also requested more information after questioning projections in population growth and water usage over coming decades.
The Group Against Reservoir Development (GARD) opposes the plan but the Angling Trust has expressed its support for
the reservoir as it believes it
could protect under-threat chalk streams.
GARD chairman Derek Stork described the consultation as a ‘shambles’ and vowed to put pressure on the Department for Environment, Food & Rural Affairs and environment secretary Michael Gove for a second consultation.
Thames Water did not respond to calls for a public inquiry but has previously said when making long-term plans it uses the best data available at the time and then revises plans when new data becomes available.
Consultation on its draft plan ended on Sunday.