Thames Barrier Annual Test Closure

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.

There will be various fun and educational activities for children, talks, demonstrations, information and display stands between 12:00 – 18:00.

Test closure event is free, but there is a fee for entry to Information Centre