Sutton Fen is on the upper reaches of the River Ant
The Royal Society for the Protection of Birds (RSPB) has been given nearly £50,000 to improve its Sutton Fen nature reserve on the Norfolk Broads.
The money, from the Biffaward environment fund, will contribute to a two-year project to restore the fragile site to its former glory.
The charity will aim to create habitats to encourage birds to breed as well as boost plant and insect life.
The RSPB bought Sutton Fen for £1.5m in December 2006.
It is said to be one of the finest examples of unpolluted valley fen in Western Europe and one of the most important nature sites in the UK.
The money will enable staff to clear scrub from the fen and reedbeds creating open areas for breeding bitterns and cranes.
Overgown ditches will be cleared for aquatic plants and animals, such as water voles, otters and the rare Desmoulin's whorl snail.
The grant will also pay for local sedge cutters to manage habitats using traditional hand-cutting techniques, to help keep the skills alive.
The installation of swing bridges will improve access for Highland cattle, whose grazing helps control the fen vegetation.
Biffaward uses landfill tax credits donated by Biffa Waste Services to fund projects that enhance biodiversity and benefit communities.