b'2 9 S E P T E M B E RTHAMES BARRIER& LONDONA family day out for someand a day of wild waterREGATTA sports for others, the Thameswill draw the crowds from Hammersmith to WoolwichO nce a year the Thames Barrier has a full test closure during which its gates rotate 90 degrees into the fully closed defence position, stopping the tide from going into London. As the tide rises, a higher level of water builds up downstream of the Barrier creating different water levels on either side of the gates. The Thames Barrier protects 125 square km of London from tidal flooding, home to 1.25 million people and a huge amount of important London infrastructure. Its built across a 520 metre stretch of river and its annual closure offers visitors the chance to see how it works and meet the teams who operate it, keeping London safe from flooding. Andy Batchelor, Thames Barrier Operations Manager, said The Barrier is quite a spectacle and the annual test closure makes an interesting and unique visit for all the family. The Thames Barrier View Caf and Information Centre will be 24THE RIVER MAGAZINE|Autumn 2019'