The Government's energy review has again raised the possibility of a tidal barrage across the Severn, contributing about 7% to the UK electricity supply. Although this is about the same percentage as could be saved by the more judicious use of electricity by all of us, its contribution can also be considered as an essential pump storage.
But on almost all occasions when a barrage is discussed, a cautionary note is entered 'that plans for a Severn barrage would raise strong environmental concerns'. Such concerns have long been recognised and in large measure addressed.
Between 1970 and 1978, a number of scientists, economists and engineers were brought together during the Severn barrage investigation by the Parliamentary Select Committee on Science & Technology, chaired by the then MP for Bristol North East Arthur Palmer, in a symposium organised by the Colston Research Society of the University of Bristol. The emphasis was on the likely changes to the ecology of the estuary.
Fourteen studies were devoted to these aspects, ranging from sedimentation to bacteriology and the distribution of heavy metals, and for the most part they are still valid.
In the UK research was funded largely by the Natural Environment Research Council, and the general conclusions were that the ecological environment would indeed be changed, - but in many instances for the better.
Professor RT Severn, Earthquake Engineering Research Centre, Department of Civil Engineering, University of Bristol, Queen's Building, University Walk, Bristol, BS8 1TR