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Environment & Climate

Thames Water revises blueprint for Oxfordshire mega-reservoir

The Guardian reports that Thames Water has updated plans for its Oxfordshire site as costs reach up to £7.5bn.

The short version

  • Thames Water has updated its proposal for the White Horse mega-reservoir near Abingdon, Oxfordshire, following cost increases and local opposition.[The Guardian]
  • The site is expected to hold 150 billion litres of water, with estimated construction costs climbing from £2.2bn to between £5.5bn and £7.5bn.[The Guardian]
  • Multiple local councils have rejected the plans, pointing to flood risks for neighbouring villages due to required river diversions.[The Guardian]
  • Thames Water plans to submit its formal planning application in late 2026 to address a regional water deficit projected for 2055.[The Guardian]

Key facts

  • Thames Water updated its design blueprint for the planned White Horse mega-reservoir near Abingdon, Oxfordshire.[The Guardian]
  • The reservoir's estimated cost increased from £2.2bn to between £5.5bn and £7.5bn.[The Guardian]
  • The planned facility will store 150 billion litres of water and cover an area of 6.7 square kilometres.[The Guardian]
  • Oxfordshire County Council, Vale of White Horse District Council, and Abingdon Town Council rejected the project due to flood risks.[The Guardian]
  • Infrastructure oversight body Rapid forecasted a water shortfall exceeding 2 billion litres per day by 2055.[The Guardian]

What remains uncertain

  • Campaigners allege Thames Water has systematically underestimated final construction costs and overstated the project's strategic value.[The Guardian]
  • Local community groups claim the utility company failed to conduct adequate consultation with residents and local bodies.[The Guardian]

Sources

Outlet counts describe coverage, not independent confirmation. Reports may share a wire service or original source.