SAVED PER YR
New intertidal habitats
Medmerry is an excellent example of how we create a sustainable legacy; protecting communities whilst working with nature. ‘Managed realignment’ involves building new defences inland from the coast and allowing a new intertidal area to form landward of the new defences. ‘Intertidal’ refers to the land that is exposed at low tide and covered by the sea at high tide.
The flood defences we constructed offer 1,000 times better flood protection than previous defences, and provide flood protection against rising sea levels over the next 100 years.
The project involved:
- 7km clay flood embankment
- 8km of access tracks and drainage ditches
- 8 concrete flood control structures
- 2 protective rock armour revetments
The uniqueness, scale and innovative ecological approaches within this scheme influenced future Environment Agency policies on the economic and environmental benefits of managing coastal flood risk.
Providing flood defence and creating environmental benefits
Our teams’ expertise in hard and soft engineering meant that habitat enhancements were at the centre of this project. For example, we used a 3D model to make best use of surplus material to form bird nesting islands. We also used Prolec GPS equipment to meet the challenge of excavating new areas of saltmarsh, accurately guiding the excavators to successfully create varying levels for the flora habitats;
We created water vole habitat over 2km of ditches using plug planting and pre-planted coir rolls, and used award winning mitigation for ground nesting birds using a ‘push-pull’ method which provided suitable habitat for key species within the 350Ha site at all times.
Saving resources through innovation and minimising global impacts
Our final cut and fill balance was virtually zero and we re-graded site won material to save 10,000m3 of imported clay which would have otherwise required over 1,000 lorry movements and their resulting carbon emissions.
Fitting into and enhancing the local community
We kept the wider community involved through a multi-media campaign, as well as volunteer input into archaeological works and visits by local schools, national and international engineering organisations.
We set up the Medmerry Stakeholder Advisory Group to bring together local residents, farmers and other bodies. We all worked together to maximise benefits to the community through various designs and landscaping. We also included the RSPB as a full project partner to be involved with our programming and to complete mitigation. They now manage the site as a publicly accessible bird reserve;
“This project will become a thriving wildlife haven and a big draw for nature lovers. We should take confidence from the success here at Medmerry and help to secure our and nature’s future by investing in these sort of landscape scale projects.”
Mike Clarke, RSPB Chief Executive