Thames Barrier

The Thames Barrier stands across the river 3.2 kilometres east of the Isle of Dogs. It divides the Thames into six navigable spans and four smaller channels between nine concrete piers. Two abutments anchor the ends of the 520-metre structure. The barrier protects 117 square kilometres of London from surges that can raise water levels by 3.5 metres. Engineers designed the rising sector gates after Reginald Draper built a working model in 1969. The barrier was completed in 1982 and officially opened by Queen Elizabeth II in 1984. Each of the four main gates weighs 3,700 tonnes and stands 20.1 metres high. The gates rotate to control upstream levels or rotate fully for maintenance. Visitors reach the barrier by walking along the raised river path from New Charlton. The piers and gate arms rise from the chalk bed of the Thames. From the southern bank, views extend west towards the Isle of Dogs and east along the straightened channel. Interpretive signs explain how the gates operate and how often they close to prevent flooding.