ExoTile Erosion Protection in Southend
➤ Autumn 2024 ➤ Southend City Council ➤ Two Tree Island
Problem
The Two Tree Island carpark in Southend Essex provides access to an important Essex Wildlife Trust nature reserve. Historically used as a landfill, the carpark is vulnerable to erosion with the existing concrete defences starting to show signs of disrepair. The type of waste stored in the landfill is not known. Consequently, replacing the existing coastal defences was needed to prevent erosion and the potential release of harmful substances into the surrounding sensitive saltmarsh habitats.
Hard engineering approaches are commonly used along areas of coastline which are vulnerable to erosion. These are very effective, but replace the natural habitats which we find in these areas.
Solution
The Catchment to Coast project forms part of the wider Flood and Coastal Resilience Innovation Partnership (FCRIP), and seeks to reduce erosion through the use of innovative Nature Based Solutions.
In collaboration with Essex University and Essex Wildlife Trust, Exo Engineering designed bespoke ExoTiles which could not only protect Two Tree Island from erosion, but also provide habitats for a variety of coastal species. A combination of 3 different sized ExoTiles were used to exactly match the dimensions of the revetment and protect the 40m stretch of land from erosion.
Additionally, it was important to reduce the amount of wave energy reflected back into the saltmarsh which surrounds Two Tree Island. To solve this problem, Exo Engineering developed Nature Inclusive wave diffusion tiles which would break up wave energy rather than reflect it. The installation represents a world-first concept, bringing together a Nature Inclusive seawall with Nature Inclusive wave diffusion tiles, maximising functional protection and habitat provision.
Results
The result is an inspiring, Nature Inclusive sea wall which not only protects Two Tree Island from erosion, preventing harmful substances from entering the surrounding saltmarsh, but also provides a broad range of habitats for coastal species.
A combination of surface textures and features provide habitat complexity which encourage settlement of coastal species, whilst also retaining water and sediment. The project highlights the benefits of using Nature Inclusive Design for both people and nature.
Clients can also make use of ExoTiles to assist them in meeting Biodiversity Net Gain requirements whilst achieving their project goals.
