Wallasea Wetlands is a reclaimed wetlands area located in Essex, England. It has been created as part of a government-funded wetlands scheme to halt the decline of wild and endangered birds caused by the drainage and development of former wetland sites. It is the largest man-made marine wetland area in the United Kingdom. An extension to the scheme, using 2,400 shiploads of spoil excavated from London's Crossrail tunnels, was completed in July 2015, when an additional area of land was opened to tidal flow. The whole project is expected to be completed by 2025.