The Thames Barrier is being closed today (Thursday, October 21) for the 200th time amid a flood alert being issued for parts of east London.

The Environmental Agency (EA) says closing the barrier and associated steel gates, which span 520 metres across the river next to Silvertown in the Royal Docks, will reduce the risk of flooding for up to 640,000 properties in London and along the Thames.

The closed barrier will protect from a high tide as a result of low pressure and northerly winds coinciding with spring tides.

Barking and Dagenham Post: The area, marked in blue, covered by the flood alertfor Tidal Thames riverside from Dartford Creek and The Mardyke to the Thames Barrier.The area, marked in blue, covered by the flood alertfor Tidal Thames riverside from Dartford Creek and The Mardyke to the Thames Barrier. (Image: https://riverlevels.uk/ website)

It comes as a flood alert is in place for the Thames riverside from Dartford Creek to the Thames Barrier, which covers parts of Barking and Dagenham, Newham and Havering.

The barrier’s 10 steel gates were due to begin moving about 10:45am and will take about 90 minutes to close completely, ahead of the high tide expected around 2.30pm.

The barrier will re-open a few hours later, around 6pm.

The Thames Barrier is the second largest moveable flood barrier in the world and forms part of the Thames Tidal Defences, which also includes the Barking and Dartford Creek Barriers.

Thames Tidal Defences operations manager Andy Batchelor said: “Since becoming operational in 1982, the Thames Barrier has offered our capital world class flood protection.

“Without it, the centre of London would have potentially been inundated on multiple occasions and millions of people would have been at risk from the misery of flooding.

“The Barrier will continue to provide that protection until at least 2070, but as we see the effect of the climate emergency with rising sea levels, we’re investing a further £54m in London, providing funding to more than 50 schemes to tackle all sources of flooding.”

While the barrier will help to protect London from potential tidal flooding, there are also risks from coastal flooding along the east coast while heavy rain also means that there is a separate risk of river flooding across the south of England.

As of 10.45am, there are 52 flood warnings (meaning flooding is expected) and 100 alerts (flooding possible) in force across the country.

The alert covering east London states: “Water will be maintained within the downstream network of flood defences, which include river walls, embankments and flood gates.

"However flooding of low-lying footpaths and open spaces is possible for 1-2 hours around high tide."

Visit https://check-for-flooding.service.gov.uk/ for the latest information.