A new 1,500-acre (607-hectare) coastal wildlife habitat is to be established by the Royal Society for the Protection of Birds (RSPB) in Essex using material excavated as part of the construction of London's Crossrail project.

Clay, chalk, sand and gravel will be shipped by boat from the centre of the capital to Wallasea Island, which is the site for Europe's largest wetland creation scheme. Designed to replace wildlife habitats damaged by the onset of climate change, the project was unveiled in 2007 and was subject to raising £12m. However, since then, the plans and costs have altered, and a planning application will be submitted by the RSPB to Essex County Council by the end of November.

The material excavated from beneath London will be used to raise land on Wallasea to create hillocks and dips, which will allow seawater in at high tide. It is hoped that a number of animals will flourish as a result, including otters and saltwater fish. A public consultation will be held in December, and a decision on the project is expected from the council by spring 2009. Crossrail works are expected to begin in 2010, with tunnelling commencing in 2011. The RSPB project is expected to take between five and 10 years.

Graham Wynne, RSPB chief executive, said: "Wallasea will be the RSPB's most ambitious and innovative habitat recreation scheme. It will create a huge new area for birds and other wildlife whose existing habits are being damaged and lost because of climate change."