The Severn Estuary supports very important habitats. Its ecology is unique. Strong protection under international law exists for such environments and rightly so. Building a huge barrage from Weston-Super-Mare to Cardiff would have very significant impacts on the estuary, its wildlife and landscape. Implications for navigation and flooding are also serious.
Its not just green pressure groups that are expressing grave concerns about a huge barrage and calling for serious consideration of tidal lagoons, tidal stream turbines or a tidal reef. Government bodies like the Environment Agency and Natural England are worried too. They think that a barrage has many implications, including legal ones. They too feel there should be serious consideration of less damaging ways of tapping the Severn's tidal energy.