THAMES BARRIER PROJECT

Draws attention to the flood risk to London as a result of storm conditions in the N Sea leading to exceptionally high water levels in the Thames Estuary. The risk is increasing because of the adverse change which is taking place in high water levels at London Bridge of about 0.6 metres per century. Due to the pattern of development of London over the centuries, the present situation is such that 115km2 of densely built-up area is at risk of flooding should the tidal Thames over-top the existing flood defences. To eliminate this risk, in 1972 the decision was taken jointly by the Government and the GLC, to build a barrier across the river in the western half of Woolwich Reach. Protection to built-up areas further downstream is being provided by raising the existing flood defences by as much as 2 metres. The Barrier has 4 main gates of 61 metres, the same width of opeing as the main span of Tower Bridge, and 6 smaller openings of 31 metres. Normally the tide will flow freely through the structure, the gates being closed only when dangerous conditions are developing in the outer estuary. The structure is now about half completed, and on the present programme the Barrier will be operable at the end of 1982. -from Authorflood risk London North Sea Thames Estuary London Bridge Woolwich Reach flood defences Tower Bridge