04 June 2009

Environment Agency - Home

The Thames Barrier

The Thames Barrier is one of the largest movable flood barriers in the world.

It protects 125 square kilometres of central London from tidal surges. That’s 1.25 million people, historic buildings, offices, power supplies, tube lines, hospitals and more. The Environment Agency runs and maintains the Thames Barrier as well as the capital’s other flood defences. These defences include floodgates like the Barking Barrier and raised river banks.  

The Thames Barrier is also one of London’s most striking and famous landmarks. With its distinctive stainless steel piers it spans 520 metres across the Thames near Woolwich. The barrier, which became operational in 1982, has 10 steel gates that can be raised into position across the River Thames if a tidal surge is predicted. When raised, the main gates stand as high as a five-storey building and as wide as the opening of Tower Bridge. Each main gate weighs 3,300 tonnes.


History of the Thames Barrier

Explore our timeline to find out about the events that led to the construction of the Thames Barrier.

Operating the barrier

Engineer working on the Thames Barrier

Access images and information showing how our tidal defences work.

Learning zone

Child with Thames Barrier in background

Would you like to learn more about the Thames Barrier?