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Proposed new reservoir in Oxfordshire

We're proposing a new reservoir in Oxfordshire. The reservoir will help protect public water supplies during periods of drought.

The new reservoir would be filled with water from the River Thames in winter, when there’s plenty of water. We'll release water if river levels drop or demand for water increases. 

Reservoirs are valuable because they provide a reliable source of water. They can also offer recreational opportunities, support wildlife habitats, and manage flooding.

What we have done so far

We launched a public consultation in June 2024. The consultation covered design options and an interim master plan for the reservoir. In summer 2025, we published our Summer Update summarising the feedback.

Alongside this, we’ve also released our Statement of Response. The Statement of Response details how we have considered the feedback we received. It also details the changes to our proposals that have been made as a result. You can find out more about our proposals online.

Upcoming public information events

We’re hosting a series of local public information events. The events will provide an opportunity to view the project plans and ask questions. You can find details of these events by visiting: thames-sro.co.uk/events. To help us manage numbers, we'd be grateful if you could register your attendance in advance.

Reservoir illustration - June 2024

This illustration reflects the conceptual design for a 150 Mm3 reservoir.

A map showing the proposed South East Strategic reservoir.

Map key

  1. Proposed reservoir
  2. Reservoir embankment with pasture, hedgerows, woodland belts and copses
  3. Environmental bundling for noise and/or visual screening 
  4. Steventon to East Hanney road diversion
  5. Indicative replacement floodplain storage and associated wetland habitat 
  6. Corridor for future Wiltshire and Berkshire canal
  7. Alternative indicative locations for T2ST water treatment works and temporary compound
  8. Pumping station
  9. Western and eastern watercourse diversions and realignments
  10. Recreational lakes
  11. Main access road
  12. Wetland lagoons
  13. Conveyance tunnel (including emergency discharge)
  14. Intake and outfall on the River Thames
  15. Indicative location for railway sidings and material handling area during construction
  16. Indicative access location for water sports centre
  17. Floating islands
  18. Indicative minor car park with restricted access
  19. Main visitor car parking

Gate 2

Gate 1