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An essential new water supply for the South East 

What’s the solution?

To protect public water supplies during periods of drought, we're proposing a new reservoir to the south-west of Abingdon. 

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

The new reservoir would be filled with water from the River Thames in winter, when there’s plenty of water. When river levels drop or demand for water increases, we'll release water from the reservoir back into the river. This will help the environment, protecting our most sensitive rivers. 

We've carried out technical assessments to determine the size of the proposed reservoir. We also consulted with regulators, stakeholders and customers. This research supported building the larger option, 150 million cubic metres (Mm3), rather than 100 Mm3. This is explained in our revised draft Water Resources Management Plan, published August 2023.

Read an update on the proposed new reservoir

South East strategic reservoir

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

Map key

  1. Proposed reservoir
  2. Reservoir embankment (grass, some trees and bushes)
  3. Screening mounds
  4. Proposed new road
  5. Wetland habitat / floodplain compensation
  6. Safeguarded corridor for future Wiltshire and Berkshire canal
  7. Water treatment works (for local supply and/or transfer to Southern Water)
  8. Underground pumping station
  9. Watercourse diversions
  10. Wetland lagoons
  11. Access road
  12. Auxiliary drawdown channel (navigable canal)
  13. Conveyance tunnel
  14. Intake and outfall on the River Thames
  15. Indicative location for railway sidings and material handling area
  16. Indicative access location for water-based recreation

Gate 2