The Environment Agency has issued an invitation for expressions of interest to develop hydropower on a further three of its weirs on the Thames: at Marlow, Boulters and Boveney despite a promise from the Regional Director in 2008 that no other Thames weirpools would be developed for hydropower until the first, at Romney, had been fully evaluated for its environmental impact. Romney has yet to be built.

This invitation follows a similar invitation on three other weirs last year (Teddington, Bell and Sunbury), and others that the Agency is working on with community groups at Goring and Osney (the latter is in addition to one already approved on the weir), and others which are proposed at Abingdon and Sonning, making a total of 11 weirs.
The Angling Trust has written to the Environment Agency’s Chief Executive strongly condemning the press release and demanding a retraction of the invitation. Angling’s representative body believes that a series of developments of this nature should be subject to an environmental impact assessment at a catchment scale. Developers should not be encouraged to draw up detailed plans for schemes, potentially supported by public funds, until this important scientific work has been done.
Weirpools are vital to the habitat and fisheries diversity of heavily impounded lowland rivers such as the Thames. They are the only features that offer suitable spawning opportunities, clean gravel shallows, for flow-dependent species such as barbel, dace and chub, among other species. The concern is that reducing the flow for much of the year will substantially affect this habitat, a view that has been substantiated by a recent independent expert report that the Angling Trust’s legal arm recently commissioned to examine the impact of a scheme on the Trent.
Hydropower schemes have several other potential impacts on fisheries, depending on the design. The EA’s Good Practice Guidelines, referred to in its press release, are currently under review after two reports from an independent fisheries scientist found that they were inadequate to protect fisheries and the ecological status of rivers.
Angling Trust Chief Executive Mark Lloyd said: “It is outrageous that the organisation charged with protecting our fisheries is selling off the river’s flow at 11 weirs without even considering the cumulative impact on fish and without having adequate guidelines in place. The River Thames won a prestigious international award last year for the work being done to restore and improve the river. Hydropower developments on this scale could reverse all that good work at a stroke and destroy a really valuable fishery.”
James Page, Chairman of the Thames Anglers Conservancy said: “weir pools are really important to anglers and fish. We are very concerned about the lack of scientific data available proving that these schemes won’t damage the ecology of the river.”