Thames Barrier Annual Flood Closure

Get down to the Thames Barrier as the Environment Agency carry out the annual test closure holding back the high tide on 23 September. There will be various fun and educational games and activities for children, talks and demonstrations, experience the visitor centre for free plus enter a prize draw!

The Thames Barrier is one of the largest movable flood barriers in the world. The Environment Agency runs and maintains the Thames Barrier as well as London’s other flood defences. Once a year, it holds a full tide test closure of the barrier.


The gates rotate by 90 degrees into the fully closed defence position, stopping the tide going upstream into London.

As the tide continues to come in, a higher level of water will build up downstream of the barrier compared with upstream.

Shortly after high tide, the gates will rotate further creating a 2 metre gap underneath (underspill).

This in turn creates a white water rush effect lasting about 2 hours behind each of the massive gate structures attracting birds to feed on small fish. 


Click here to find out about this event and many more on and around the river as part of the Totally Thames festival.


External Sources

Totally Thames festival website: What’s On