[svenrufus]

An alternative proposal to the idea of a barrage across the whole Severn (or other) estuary - which would be absolutely unacceptable on ecological grounds - is the use of Tidal Lagoons, which are a similar idea in the way they work using the ebb and flow of the river/tide, but rather than damming the whole river, they create 'pockets' of water contained in discreet areas where the ecological impact is less.

This allows more manageable energy capture and release, as the water can be allowed to flow in or out of the lagoons at times to suit, to meet peak demand. It can also be delivered much quicker than the barrage scheme and is, in terms of resources (material and financial), a better investment. It is the way forward for this particular area.

Trouble is that the government seems to be hooked on grand scale big engineering schemes - looks more impressive and shows 'real action'. Same way they like to back plans for huge new reservoirs rather than legislate for water efficiency measures.