A managed coastal realignment scheme to overcome flooding between Portsmouth and Worthing was completed last week. The £28m project will involve surrendering 183 hectares of land to the sea to form a saltwater marsh.
Seven kilometres of new sea wall has been built up to two kilometres inland; part of the old sea wall has been knocked down at Medmerry, West Sussex, to allow the flat land on the coast of the Manhood Peninsula to be inundated with sea water. The new sea wall is much closer to local communities, but homes will be better protected as a result.
The surrendered land will have the potential to become home to many new species, and the area will be managed by the RSPB. “It is already starting to be used by the wildlife. It’s a massive nature reserve and a massive opportunity on the south coast” said Andrew Gilham, the Environment Agency’s flood and coastal risk manager. “Even in construction, we’re seeing lots of migratory birds using this area”.
The Environment Agency has been working on this scheme since 2011, and it is set to be the country’s largest managed realignment scheme. The project was put to the test from the word go, with one of the highest tides of the year occurring on the day it opened. However this new coastal defence is believed to be able to withstand a one-in-one-thousand-year flood.
“Rather than fighting it, we’re working with nature” Andrew Gilham explained. “It’s an important change in approach, you can only keep building bigger and bigger defences for so long”. As well as benefiting the south coast in terms of protection from the sea, the scheme has the potential to improve tourism in the area, bringing people to less-known areas to see the wetland habitat. “Certainly the habitat we are creating here is important to the broader ecosystem and the broader economy of the country by encouraging people to visit remote areas”.