I'm all for it and no half-measures
And I have to say, as a regular Severn estuary recreational water user, don't let them tell you the place is an important habitat for millions of nice birds and fish. The place is a _marine desert_ almost devoid of marine life and therefore not home to a lot of wading birds. There is too much silt in the water which makes it opaque to sunlight which means very little plant life which supports very little fish life which supports very little bird life.
Plus, the tidal range is approximately halved by the barrier, not eliminated, therefore some inter-tidal zone will remain which will most likely support _more_ life than before.
One can only hope there is a way to stop the big tidal barrage from silting up.