Severn Estuary: Tidal Barrage (Hansard, 30 November 1987)

§ Lord Gainford
My Lords, I beg leave to ask the Question standing in my name on the Order Paper.

§ Viscount Davidson
My Lords, the current programme of work on the Severn barrage includes studies of environmental aspects. Indeed, to facilitate this the Severn Tidal Power Group has set up an environmental advisory panel which will look into these aspects.

§ Lord Gainford
My Lords, I thank my noble friend for that Answer. Has he any information about a survey of the soil and the ground-bearing strength for this project and have any conclusions been drawn?

§ Viscount Davidson
My Lords, core samples of the estuary bed have been taken by a drilling barge. Sonar and seismic surveys have also been made of the area along the possible line of the barrage. However, a fully detailed survey will not be completed until it is required for final design purposes.

§ Viscount Hanworth
My Lords, does the noble Viscount agree that any large project has some unfortunate environmental effect, and provided that it is not excessive, that is no reason for turning the project down?

§ Viscount Davidson
My Lords, I agree that tidal energy is one of the most promising of our renewable resources. The current research programme which concentrates on the Severn and Mersey estuaries is aimed at reducing uncertainties on cost, performance, regional and environmental issues.

§ The Earl of Lauderdale
My Lords, will my noble friend say whether any other estuaries have been examined for that purpose, and notably Kylesku on the West Coast of Sutherland?

§ Viscount Davidson
My Lords, I do not have any details about that particular estuary but I can say that outline feasibility studies have been carried out for the Dee estuary, Morecambe Bay, Solway Firth, the Humber and the Wash. However, all those areas are less favourable economically than the Severn or Mersey estuaries.

§ Lord Moran
My Lords, while acknowledging and paying tribute to the efforts that the Severn Tidal Power Group is making to deal with environmental problems, including the problem of the passage of migratory fish through any barrage, is the noble Viscount aware of the scientific work undertaken in the United States which suggests that fish passing through Kaplan turbines of the kind planned on the Severn barrage have an instantaneous mortality rate of between 11.5 per cent. and 80 per cent. and that 43 per cent. of salmon smolts passing through such turbines lose 20 to 28 per cent. of their scales; moreover that 75 per cent. of those that survive have gross or microscopic lesions? In the light of that knowledge, will the noble Viscount ask those responsible to consider very carefully alternatives to migratory fish passing downstream through the turbines, such as the establishment of free gaps at each end of the barrage?

§ Viscount Davidson
My Lords, I shall certainly draw the noble Lord's remarks to the attention of those involved.

§ Lord Stoddart of Swindon
My Lords, does the noble Viscount agree that in fact there may very well be environmental gains in the Severn estuary in that a tidal barrage could encourage a greater diversity of flora and fauna in the area? Will he confirm that the creation of a tidal renewable energy source will bring environmental gain, in that fewer coal-fired and nuclear generating plants will be required, thus reducing any increase in the amount of carbon dioxide, nitrous oxide, sulphur dioxide, nuclear wastes and radiation released into the environment?

§ Viscount Davidson
My Lords, the noble Lord, Lord Stoddart of Swindon, may well be right on both points. The environmental studies that are now in train are designed to clarify areas of uncertainty and to explore those that require further study, so as to assemble information which can be developed into an environmental impact assessment to support a decision to proceed with construction.

Lord Campbell of Croy
My Lords, while the barrage scheme for the Severn has been under consideration it has been possible for assurances to be given about damage to birds and other wildlife. Is my noble friend again able to give assurances that a difference in the levels of the water will not seriously damage wildlife?

§ Viscount Davidson
No, my Lords, I am afraid that I cannot give any assurances at this stage, as this is part of the study that is being carried out at the moment.

§ Baroness White
My Lords, is the noble Viscount able to tell the House whether anyone is looking at the possible inter-relationship between the smaller Taff barrage which is proposed and the adjacent Severn barrage, which could have considerable effects on birds and other wildlife?

§ Viscount Davidson
No, my Lords, I am afraid I do not know the answer to that question, but I shall draw it to the attention of those involved.

§ Lord Cledwyn of Penrhos
My Lords, the House debated the Bondi Report five years ago, since when there have been at least three inquiries into the viability of the scheme, in addition to the Wimpey Atkins Report. Can the noble Viscount say what has happened to all those reports? Why are the Government taking such a long time to make a statement and to make up their mind? Will he be good enough to indicate the conclusions at which the Government have arrived on the three major inquiries that have taken place and when they are likely to make a statement?

§ Viscount Davidson
My Lords, the Government have reached the conclusion that we should get on with further in-depth research and planning into the practical rather than the theoretical. Your Lordships may not understand quite how large the scale of the Severn barrage project is, affecting as it would an extensive regional area and the interests of many individual and institutional bodies. The depth of knowledge acquired so far on many topics does not allow us to satisfy at the moment all the relevant questions which can be asked on the various aspects of the scheme. If we had gone ahead without looking further into these matters we should have been criticised.