The Thames Barrier Flashcards
Cost, became operational, expectation it would last to.
£535 million, operational in 1982 with an expectation it would last until 2030.
How big?
It is the world’s largest moveable flood barrier, spanning 520 meters across the River Thames at Woolwich.
How many times it has protected London from floods.
By July 2007, the barrier had been put into operation 103 times to prevent London from flooding.
Why protect London?
Highest population density in Britain, over 4500 people per square kilometer. Major centre for international business and commerce, generating 20% of the UK’s GDP and built along floodplain along the banks of the Thames Estuary.
Technology Used
9 concrete island, containing 6 openings for vessels to pass, and 4 smaller openings that remain open. islands are built on a base of chalk 17 meters below the seabed. Curved steel gates sit on the riverbed in concrete sills between the islands and when necessary are rotated upwards to stop floodwater pushing up the Thames.
How much can the walls hold?
They weigh around 3700 tonnes and can each withstand an overall load of 9000 tonnes
Information to open the gates
50 staff collect information every 15 mins from 5 monitoring stations on the East of England. Information about the height of the waves every minute from 11 stations along the Thames. Computer models are produced from these stations and a decision is made.
Is a new barrier needed
In 2005 scientists same to the conclusion that a new flood barrier would be needed to protect London in the future. With rising sea levels, the level of flood defense offered will not be enough in the future.
Plans for new barrier
In 2007, plans were put forward for a new £30 billion flood defense scheme intended to offer London protection from a one in one thousand year flood event.
