A Quick Overview of Thames Barrier
The Thames Barrier is located downstream of central London. Operational since 1982, its purpose is to prevent the floodplain of all but the easternmost boroughs of Greater London from being flooded by exceptionally high tides and storm surges moving up from the North Sea.
When needed, it is closed (raised) during high tide; at low tide it can be opened to restore the river's flow towards the sea. Built approximately 3 km (1.9 mi) due east of the Isle of Dogs, its northern bank is in Silvertown in the London Borough of Newham and its southern bank is in the New Charlton area of the Royal Borough of Greenwich.