A major scheme to create swathes of coastal marshland with spoil from the Crossrail project reached a significant milestone this weekend with the planned breach of long-standing sea walls.
Over 3M.t of excavated material from the trans-London rail project has been used to raise part of Wallasea Island in Essex by an average of 1.5m. This is part of an ambitious programme to create lagoons and other wildlife-friendly features.
The Wallasea Island Wild Coast project, just north of Southend-on-Sea, will transform 670ha of farmland, an area about 2.5 times the size of the City of London, back into the coastal marshland it was some 400 years ago.
This weekend, the first phase of the project was completed when the sea walls were successfully breached to allow for tidal flow into the marshland.
Martin Harper, conservation director at the Royal Society for the Protection of Birds (RSPB) - which is jointly managing the project with Crossrail - said “At a time when nature is in crisis, we believe Wallasea sets a new benchmark showing what’s possible with smart regulation and intelligent partnerships between the private sector and charities.
“By moving spoil from central London to a part of the coast below sea level and vulnerable to flooding, the partnership is allowing the completion of a major transport project which will boost the economy, while providing an area that will become of international importance for wildlife. All sectors including the government now need to exploit this inventiveness to unlock other projects on a similar scale for the benefit of wildlife, people and the economy.”
Crossrail chief executive Andrew Wolstenholme said: “Crossrail has helped deliver one of Europe’s most significant conservation projects on Wallasea Island.
“This trailblazing partnership with the RSPB is a key part of Crossrail’s sustainability strategy and demonstrates the benefits that can be achieved when the construction industry and environment groups work together. This major new wetland will be a lasting environmental legacy of the Crossrail project for generations to come as well as supporting economic growth and jobs through an increase in tourism to the local area.”
Four hundred years ago there were 30,000ha of intertidal saltmarsh along the Essex coast. Now there is 2,500ha. Intertidal saltmarsh is a crucial wildlife habitat for a wide variety of plants, invertebrates and birds, and acts as an effective sea defence for local communities
Wetland restoration began on Wallasea in 2006 when sea walls were breached on the northern edge of the island. By 2025, the RSPB’s Wallasea Island Wild Coast Project plans to have created 148ha of mudflats, 192ha of saltmarsh, and 31ha of shallow saline lagoons. Around 13km of coastal walks and cycle routes will be made.
Some 98% of Crossrail’s excavated material has been recycled or re-used, with almost half being shipped to Wallasea Island. At its peak six ships arrived at Wallasea each day, unloading 8,000t of material.
The RSPB will require more than 10M.t of excavated material to create the reserve, and hope that species such as the avocet, redshank and lapwing will return in significant numbers along with large flocks of brent geese, dunlin, wigeon and curlew in winter. Plants such as samphire, sea lavender and sea aster are expected to thrive.