FREE

Get down to the Thames Barrier as the Environment Agency carry out the annual test closure holding back the high tide. 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, the Environment Agency holds a full tide test closure of the Thames Barrier. The Barrier 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 creating a different water level either side of the gates. 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 behind each of the massive gate structures attracting birds to feed on small fish. This ‘underspill’ lasts approximately 2 hours.