Lower sea walls prevent flooding? Suffolk island to be protected from rising sea levels
PUBLISHED: 19:01 13 November 2018
The sea wall of an island off the coast of Suffolk is being lowered by almost half a metre to prevent it flooding in stormy weather.
Havergate Island, a heath area of outstanding natural beauty close to Orford Ness, will have over 500m of wall reduced in height to allow water to flow into the natural lagoons around it during storm surges.
Water levels are rising due to climate change and ecologists believe this project will protect the island, a habitat for native birds, for years to come.
Visiting the nature reserve last week, Environment Minister and Suffolk Coastal MP, Thérèse Coffey said: “This project to protect Havergate Island is a fine example of natural flood management and I’m delighted to see for myself how the works are progressing.
“Flood defence technology and engineering is improving all the time and the project shows how by using a mix of natural and concrete defences, we can provide the best flood protection for individual areas.”
The RSPB, which is carrying out the work with funding from The Environment Agency together with Risk Management Authorities, Natural England and Forestry Commission, is lowering a 650m stretch of seawall at the rear of Havergate Island’s lagoon by approximately 450mm.
A slope, reinforced with netting, will be created for water to flow down before being covered with a native grass and seed mixture.
Aaron Howe, RSPB Sites Manager for the South Suffolk Coast: “Decreasing the height of the seawall may seem like a counter-intuitive way to protect Havergate Island’s wildlife from the sea.
“Doing allows us to direct the water into the island’s lagoons when there is a tidal surge before it reaches the point of overwhelming the seawall.
“This kind of natural flood management means we can keep Havergate Island’s habitats safe at the same time as contributing towards alleviating the impact of future storm surges elsewhere on the estuary.
“It’s a win-win situation, and the kind of thing I’m sure we will see more of in response to rising sea levels impacting on people and nature on the Suffolk coast.”
Havergate Island has been an RSPB nature reserve since 1949, after avocets were found breeding on the island in 1947.
Until then, avocets had been extinct as breeding birds in the UK for more than 100 years.
The island is also home to the rare yellow-striped bear spider, starlet sea anemone along with a wealth of rare coastal plants.
In recent years, increasingly frequent tidal storm surges have taken their toll on the island’s habitats and wildlife, damaging the seawall, flooding lagoons and washing away shingle banks.
The Environment Agency’s Guy Cooper said: “The work at Havergate is part of efforts to develop our understanding and evidence of adaptation and flood defence techniques on this dynamic coastline.
“The aim is to find out what techniques work well so that we can consider them alongside future flood and coastal erosion risk management schemes.”