No. 8
It's almost low tide on a sunny October morning and you can see part of two of the gates of the Thames Barrier. To the left, 8 is in the closed position and to the right of the gate mechanical and hydraulic mechanisms, 7 is open.
The Thames Barrier spans 520m across the River Thames near Woolwich, and it protects 125 square kilometres of central London from flooding caused by tidal surges. It has 10 steel gates that can be raised into position across the River Thames. 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.
The whole barrier is closed under storm surge conditions to protect London from flooding from the sea. It may also be closed during periods of high flow over Teddington Weir to reduce the risk of river flooding in some areas of west London including Richmond and Twickenham.
In such cases the Thames Barrier will then remain closed over high water until the water level downstream of the Thames Barrier has reduced to the same level as upstream. This is a managed process to provide for different circumstances, and takes about five hours. The barrier is then opened, allowing the water upstream to flow out to sea with the outward-bound tide.
The Environment Agency has closed the Thames Barrier 193 times since it became operational in 1982 (as of June 2020). Of these closures, 106 were to protect against tidal flooding and 87 were to alleviate tidal/fluvial (river) flooding. The frequency of closures has increased over recent decades:
In the 1980s there were four closures
In the 1990s there were 35 closures
In the 2000s there were 75 closures
In the 2010s there were 79 closures
In the 2020s there have been none so far (as of June 2020)
The barrier is currently expected to be in service until at least 2030, and possibly as far into the future as 2070, although scientists and academics are already suggesting that a replacement needs construction now.
Part of the new financial developments on the Isle of Dogs can be seen in the background.
No. 8
It's almost low tide on a sunny October morning and you can see part of two of the gates of the Thames Barrier. To the left, 8 is in the closed position and to the right of the gate mechanical and hydraulic mechanisms, 7 is open.
The Thames Barrier spans 520m across the River Thames near Woolwich, and it protects 125 square kilometres of central London from flooding caused by tidal surges. It has 10 steel gates that can be raised into position across the River Thames. 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.
The whole barrier is closed under storm surge conditions to protect London from flooding from the sea. It may also be closed during periods of high flow over Teddington Weir to reduce the risk of river flooding in some areas of west London including Richmond and Twickenham.
In such cases the Thames Barrier will then remain closed over high water until the water level downstream of the Thames Barrier has reduced to the same level as upstream. This is a managed process to provide for different circumstances, and takes about five hours. The barrier is then opened, allowing the water upstream to flow out to sea with the outward-bound tide.
The Environment Agency has closed the Thames Barrier 193 times since it became operational in 1982 (as of June 2020). Of these closures, 106 were to protect against tidal flooding and 87 were to alleviate tidal/fluvial (river) flooding. The frequency of closures has increased over recent decades:
In the 1980s there were four closures
In the 1990s there were 35 closures
In the 2000s there were 75 closures
In the 2010s there were 79 closures
In the 2020s there have been none so far (as of June 2020)
The barrier is currently expected to be in service until at least 2030, and possibly as far into the future as 2070, although scientists and academics are already suggesting that a replacement needs construction now.
Part of the new financial developments on the Isle of Dogs can be seen in the background.