It is the world’s second largest after theOosterscheldekering barrierin the Netherlands.
The barrier is made up of 9 steel gates reaching 520m across the river.
When closed, the gates are rotated upwards until they block the river.
The gates are filled with water when submerged and empty as they emerge from the river.
Photo credit
Flooding has been a problem in London for centuries.
Construction on the Thames Barrier began in 1974 and was officially opened a decade later.
Graphics credit:The Guardian
Graphics credit:BBC
Flood barrier open.Photo credit
Flood barrier closed.Photo credit
