Conservation

Protecting sites in England

Abingdon Reservoir, Oxfordshire

Leaking tap

Thames Water plans to build the UK’s largest fully bunded reservoir on farmland near Abingdon, Oxfordshire, as part of their 25-year water resources plan. 

The reservoir would be enclosed by earth bunds, covering a surface area of about 12 square kilometres. It would have a useable output equivalent to the current combined output of Grafham Water and Rutland Water.

Thames Water would take water from the River Thames at periods of high flow to top up the reservoir, and release it back into the river to supply London, downstream. Eighteen percent of the output will be used to top up Farmoor reservoir, near Oxford.  Several other water companies in southern England are also likely to get a share of Abingdon’s potential output, including to supply the Swindon area.

Consultations

Thames Water is consulting people on this huge project in several stages. In autumn 2006, they consulted on the need for and alternatives to the reservoir. In spring 2007, consultations on the broad design and options for use of the reservoir took place. Later in 2007, we expect details of an Environmental Impact Assessment and detailed engineering and design work to be published for comment. If all these matters are approved, construction could begin in around 2011, and the reservoir could be completed by 2020.

The RSPB’s involvement

The RSPB does not currently support the development of this reservoir. We believe alternative ways of meeting public water supply need must be fully explored first, including adopting the highest standards for sustainable water use in all new housing in the area intended to be served by this reservoir. We also believe Thames Water need to do more to tackle leakage, and explore ways of reducing demand for water through, for example, implementing ‘smart’ metering for homes to allow variable tariffs that can encourage efficient use.

The RSPB believe alternative ways of meeting public water supply need must be fully explored first

If the reservoir proposal were allowed to go ahead, the RSPB would expect several conditions to be met in terms of the design and use of the reservoir. 

 The most critical points are:

  • The reservoir must be designed to achieve ‘Good Ecological Potential’ as an artificial water body under the European Water Framework Directive.

  • The reservoir’s pumping regime for filling and discharge would need to be compatible with maintaining the conservation status of the River Thames and other water bodies.

The following considerations are also important:

  • The reservoir proposals should be accompanied by a ‘compensation plan’ that would deliver wildlife habitats such as wet grassland and reedbed.  Provision must be made for long-term management of these habitats.

  • Thames Water will have a considerable surplus of supply over demand once the reservoir is commissioned.  Therefore, the proposal should be accompanied by a commitment to give up abstraction licences identified as a risk to protected wildlife site in Thames Water’s resource zones.

The RSPB has responded fully to all of the consultation stages so far, and will continue to maintain a close interest in the project. We are participating in the Ecological Forum set up by Thames Water to address wildlife issues connected to this proposal, and are actively discussing broader water resource issues with the Environment Agency with the aim of ensuring that this proposal, if it goes ahead, is fully justified and demonstrates best practice in all its details.

 

Last modified: 16 April 2007