Changes have been agreed to try to encourage more birdlife at Pulborough Brooks at a meeting of the South Downs National Park Authority.
The authority’s Planning Committee voted unanimously for the plans for four new hydrological structures to help control water levels and ensure areas don’t dry out at the RSPB (Royal Society for the Protection of Birds) site.
The 393-acre (159-hectare) site mainly consists of grazing marsh and a series of ditches, serving as part of the River Arun’s floodplain.
It is home to species such as lapwing, nightingale, short-eared owl and the incredibly rare little whirlpool ramshorn snail.
But, the national park authority said, the lack of hydrological controls has started to become a real issue in recent years, compounded by a more unpredictable climate.
Reduced water levels across the site and compaction of ground at key locations have made some areas unsuitable habitat for wading birds.
The lack of water flow has also caused the silting up of ditches and reduced water quality, affecting plants and insects as well as the birds.
The new dams and sluices will maintain a steady water level and also ensure more “muddy edges”, which are essential for feeding purposes for wetland birds.
The planning approval is the first milestone in the £1.7 million Downs to the Sea project, which started last month with a plan to restore and create a network of “blue spaces” across the region.
The national park authority said: “Downs to the Sea will help carry out much-needed restoration work to a number of internationally designated wildlife sites, including RSPB Pulborough Brooks and RSPB Pagham Harbour.
“The initiative will restore 15 ponds in the national park to create biodiversity hotspots and support the movement of wildlife between sites.”
Downs to the Sea project manager Natacha Bricks-Yonow said: “This is a wonderful first step towards improving wetlands across the region and encouraging more wildlife.
“There’s still a lot of work ahead in terms of delivering the improvements but gaining planning permission for this particular project is a big win for us.”
Oriole Wagstaff is the senior site manager for the RSPB South Downs Reserves including Pulborough, Amberley, Adur and Lewes.
She said: “We’re delighted to be given planning permission for this important work.
“This project will increase our ability to manage water on site, helping to improve our wetland habitats and support a huge range of threatened wildlife.”
Downs to the Sea is a partnership between the South Downs National Park Authority, South Downs National Park Trust, RSPB, Brighton and Hove City Council, Western Sussex Rivers Trust and Writing Our Legacy.
