Development proposals for the Ouse Fen Nature Reserve

Proposed development at Needingworth and Over for the Ouse Fen Nature Reserve by Hanson Aggregates and the RSPB


New wetlands can make a major contribution towards achieving UK biodiversity targets through securing the future of important wildlife habitats and species.

East Anglia is of outstanding importance because it contains a significant proportion of key wetland habitats that support some of our most threatened species. These include reed beds (50% of the UK resource); swamp fen remnants such as Wicken and Woodwalton Fens (80%), and seasonally flooded grassland such as the Ouse Washes and Nene Washes (15%).

The Fens are important because of:

  • the internationally important populations of wintering ducks and swans that use the large wash lands and surrounding farmlands;
  • the internationally important remnants of former swamp fens, which support a number of plants and invertebrates found nowhere else in the UK;
  • the nationally important populations of breeding waders concentrated on the Ouse and Nene Washes in spring and summer;
  • the extensive network of farm ditches and larger drains, which provide refuges for relict fen plans and invertebrates, and support characteristic birds including reed warblers;
  • its potential to create new wetland.


The UK Biodiversity steering group report, adopted by government in 1996, identifies those species and habitats of highest priority for conservation action in the UK. The Fens supports, or has the potential to support, a number of priority species including otter, water vole, bittern, fen violet and swallowtail butterfly. Therefore the area is an important focus for conservation action.

Since 1600, some 97 per cent of the original wetlands have been lost and species have been confined to smaller and smaller sites. Some, such as bittern and the spectacular swallowtail and large copper butterflies, have disappeared altogether as fenland breeding species. The loss of habitats places more species at risk and increases the need for expensive specialist management. More habitat is needed to sustain these remnant populations for which the Fens is so important.

Large Copper Butterfly

Large Copper Butterfly, one of the target species of the Ouse Fen nature Reserve

Large Copper Butterfly, one of the target species of the Ouse Fen nature Reserve


External factors, such as the threat of accelerated rates of coastal erosion on the East Anglian coast also have implications for the Fens. Anticipated sea level rise and increased storminess are likely to lead to accelerated losses of freshwater wetlands of national and international importance on the East Anglian coast.

Creating new habitat suitable for important species is a technical challenge. Pioneering habitats such as reed beds and seasonally flooded grassland are relatively easy to create and can quite rapidly support key wetland species such as wildfowl. The creation of other habitats such as peat based fen is a far greater challenge, as this requires conditions where new peat can form and accumulate over many centuries. Restoring fens from low level mineral workings may provide the only real opportunity for long-term creation.

What Ouse Fen will look like in the future

The future Ouse Fen Reserve by Bruce Pearson

The future Ouse Fen Reserve by Bruce Pearson


The Fens is a unique and special area. It owes it existence to its origins as the nation's largest lowland wetland with impassable swamps, rich grazing and abundant fish and other wildlife. The links to this wetland past are strong and remain in the rich dark soils, the pattern of settlement, and in the wildness of the last remaining wetland fragments.

Wetlands are an increasingly scarce resource throughout the world. Within the Fens only a few large sites escaped drainage: Wicken and Woodwalton Fens are now recognised as internationally important wildlife habitats as Special Areas of Conservation (SAC). The large wash lands of the Ouse and Nene rivers, which attract internationally important numbers of wildfowl species including Bewick's swan and wigeon, are designated under the RAMSAR convention. Smaller fragments, containing typical fenland wildlife, such as reed buntings and dragonflies, remain in every ditch and drain with reeds being the living sign of wetland past.