The tides of the Severn Estuary are the highest in Europe. Their vast energy could be harnessed to generate a tenth of the country's electricity by the end of the century. But it would mean building a ten-mile dam across the estuary at a cost of £5,500-million. Is it worth it? And what about the far-reaching effects on the environment?
After two years' deliberation the Government's official Severn Barrage Committee is publishing its findings. In an exclusive preview, reporter John Norman examines the committee's conclusions and asks: should the Severn Barrage be built?
Photography DAVID SAUNDERS Film editor BILL OXENHAM
Producer MARGARET BENTON BBC West