Water specialists and RSPB unite in project on East Anglia's mega-marshes
PUBLISHED: 07:30 09 December 2017
In one of East Anglia’s wildest and widest of wildernesses, H2O is the most precious of resources - for people and for wildlife. A major £2.1million water engineering scheme is bringing benefits for both.
In the vastness, the flatness and remoteness of East Anglia’s largest area of grazing marsh, it’s easy to forget that the immense and wild lowland of Halvergate Marshes is an engineered landscape.
Far to the south, barely discernible crinkles on the widest of skylines are the distant blurs of the Suffolk and Norfolk borderlands. Way to the east is the brutal, functional, silhouette of Great Yarmouth. On the edge of visibility to the north, the occasional train flashes by, heading to or from Norwich, and vehicles hurry along the geometrically direct Acle Straight.
The middle of the marshes seems other-worldy. Except that this is a world largely created by man. Out here numerous historic mills offer a reminder that this is a worked and working landscape - grazing marsh was wrought from saltmarsh in a process that originally commenced about 400 years ago and the land is criss-cossed by labyrinthine man-made drainage ditches.
They may be steeped in history, but Halvergate Marshes have huge contemporary importance - they offer livelihood to graziers and life to a dazzling array of wildlife species. And now they are being engineered once again.
The marshes - their grazing animals and their wealth of highly specialised wildlife - need water. Somewhat ironically, there’s plenty of it nearby as their southern edge is bounded by the great estuarine sweep of Breydon Water. But salinity is an enemy. The marshes’ lifeblood is fresh water, untainted by salt.
That is why the marshes are being engineered once more - the Halvergate Marshes Water Level Management Improvement Scheme is providing a reliable supply of this most precious of resources across the vastness, and creating exciting new wetland wildlife habitats as well. The £2.1million scheme, funded by the Environment Agency, is being carried out by the Water Management Alliance on behalf of the Broads Internal Drainage Board and in partnership with landowners who include the RSPB, which owns Halvergate’s Berney Marshes - the most remote of all the society’s nature reserves.
Paul George, the alliance’s site manager for the project, said a new four-kilometre watercourse leading from the River Bure near Stracey Arms would allow fresh water to be stored and used for the benefit of farming practices and wildlife. The watercourse, known as a Higher Level Carrier, was constructed with clay taken from the site to embank the new channel. It would enable about 60,000 cubic metres of fresh water to be stored at any time - “it will give a reliable supply of fresh water and help the farming practices and wildlife, especially in times of drought or flood, and will allow the marshes to adapt to climate change in the future,” he said.
The first year’s construction was completed in September and, following water vole and nesting bird mitigation work next spring, construction was due to be finished by the end of autumn next year, he added.
The RSPB’s Berney Marshes site manager, Mark Smart, buzzed with excitement at the prospect of the wildlife benefits being offered by the project. “Our only source of fresh water is from the River Bure and everything for us depends on the level of its salinity - we have to get fresh water but the Bure is at risk from tidal surge events that bring saline water all the way in,” he said.
“It’s a major worry and a problem that affects us and all the Broads. Climate change predictions show that it is going to become harder and harder, with longer periods without rainfall, to get the fresh water we need, so this project is extremely important for the future of wildlife and the grazing on Halvergate and it gives much better controls of water levels.”
Wetland habitat creation within the project was “really exciting”, said Mr Smart. Along some parts of the new watercourse only one side of it would be embanked, allowing water levels on the adjacent marshes to rise and fall naturally, creating a “floodplain washland network” that should prove enticing for many bird species.
In addition, the excavation of clay needed for new embankments in the project had offered the chance to create new shallow lagoons ideal for nesting waders such as avocet, lapwing and redshank, and giving high-tide roosting opportunities for wading birds from the nearby estuary.
Halvergate Marshes - the second largest area of grazing marsh in the UK - were of international wildlife importance, being covered by designations such as Sites of Special Scientific Interest, the Broadland Special Protection Area, the Broadland Special Area of Conservation and the Broadland Ramsar designation in relation to its wetland bird species.
“Our Berney Marshes reserve is never going to be a Minsmere or a Titchwell because it is, after all, so wild and remote and that is a major part of its beauty and importance,” said Mr Smart. “There’s no vehicular access, although you can get a train to Berney Arms station, and it is challenge to get here. You really have to want to get out here but, if you hit it right, it’s certainly worth the effort.
“The work in the scheme will help bring birds closer to the people who do make the effort - the ones who like a bit of an adventure, the ones who like seeing wildlife in a truly wild and remote place.”