Geograph - photograph every grid square

A major sluice structure originally constructed to control water flow from the tidal east in and out of the brackish west. Regrettably plans to import more London clay from the London Tideway Project fell through necessitating redesign of the western part of the reserve and leaving this concrete white elephant high and dry. However, white elephants in nature reserves don't remain unexploited for long and plans are underway to adapt the sluice channels to provide nesting opportunities for swallows, house martins and owls as well as roosting sites for bats