The United Kingdom is in the middle of a massive flooding crisis. For the fourth time in a decade, large parts of Northern England are underwater following high levels of rain that caused riverbanks to burst on Boxing Day.
For Londoners, the images of the devastation in Lancashire and Yorkshire can seem very distant — it’s easy to forget that London is built on the banks of a massive, tidal river.
For much of its history, London has been plagued by floods. In 1928, a combination of melting snow, a high tide and a storm surge caused the Thames river to burst its banks, devastating central London. Iconic landmarks including the Houses of Parliament, The Tate Gallery, and the Tower of London were surrounded by water. Following the 1928 flood and a storm surge in 1953 that left parts of East London under water, the Thames Barrier was built to prevent tidal water surging up the Thames and into London.
However, each year large swaths of London have a 1-in-1000 (0.1%) or 1-in-100 (1%) chance of flooding.
The map below, from the UK’s Environment Agency, shows the risk of flooding across London.
The areas shaded in blue represent regions that are at risk of flooding from rivers and the sea. The darker the blue, the higher risk that region has of flooding each year.
The light blue shading represents a “low risk” of flooding, which means that each year there is up to a 1% chance that it will flood. Weather forecasters are calling some of the flooding in Yorkshire a “one-in-100-year flood,” for example. You can see that most of central London is in light blue.
The areas of darker blue are “high risk” areas, which means they have a 1-in-30 (3.3%) chance of flooding each year. These “high risk” areas are dotted around the Thames rive.
You can check out the Environment Agency map for yourself to see what risk your house is at here.
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