Londoners are being invited to visit the Thames Barrier, on Sunday 4 October to see one of the largest flood barriers in the world in action.

One of the Environment Agency’s best known roles in London is to manage the risk of flooding. The Thames Barrier is one of the largest moveable flood barriers in the world, and it is in operation 24 hours a day, 365 days a year.

This year the Thames Barrier celebrated its 25 year anniversary - the Barrier, which initially had a design specification up until 2030, should now protect Londoners for at least 40 extra years, until 2070. This legacy of the original Barrier designers is just one of the key findings from a six-year investigation called the Thames Estuary Plan – or ‘TE2100’ led by the Environment Agency into the future of flood risk management within the Thames estuary.

To date, the Barrier has been used 114 times to protect 125 square km of central London and 1.25 million people from flooding. It stretches 520m across the River Thames at Charlton. The deepest foundation measures 17 metres (56ft) below the sea bed, which is equivalent to four double-decker buses stacked on top of each other.

The Barrier closes each month as a test to ensure the gates are functioning properly but once a year, a full test closure is performed over a high tide – with the gates remaining closed for several hours, allowing a multitude of technical checks to be carried out. Each gate takes 10 to 15 minutes to close (1½ hours for total Barrier closure).

Andy Batchelor, who manages the Thames Barrier, said:

“The Thames Barrier is one of the best tidal defences in the world and we welcome members of the public to come along on October 4 to see this amazing structure in all its glory at close quarters from the Riverbank and Information Centre. Climate change is a reality for all of us and this is an excellent opportunity to see how the Environment Agency is defending London from rising tides for years to come.