The Fens

Our landscape

The project takes its name from the Old West River — the part of the Great Ouse flowing east from Earith, at the southern end of the 21 mile long Ouse Washes. From Earith, the river meanders through the countryside until it reaches its confluence with the lower Cam and Ely Ouse just south of Stretham.

Our heritage

The project focuses on the natural heritage of the fen areas on either side of the Old West River. The river corridor provides a continuous habitat of verdant riverbanks and washland along its length. There are a number of important wetland sites, numerous parish-owned community green spaces, and many hectares of farmland. There is an extensive ditch network, some of which is particularly valuable for aquatic plants and invertebrates. Collectively this contributes to the landscape’s recognition as an area of high biodiversity value, with great potential for enhancement.


The landscape’s importance for wildlife

The countryside around the Old West River is an important stronghold for rare and threatened species. It is located in between the rapidly expanding RSPB Ouse Fen wetland reserve and Ouse Washes to the west, and the National Trust’s 100-year Wicken Fen Vision area to the east, potentially creating a significant habitat corridor in between. These renowned sites at either end of the Old West River landscape are also of international importance for their lowland wetland habitats and species.

The river corridor is of significant biodiversity value: it is a stronghold for many rare and threatened species, such as the water vole and greater water parsnip. The extensive ditch network across the area is often referred to as “the hedgerows of the fens” because of their high nature value. The area is also a stronghold for highly threatened farmland birds including turtle doves and lapwing. Many of the community green spaces within and around the area’s villages support rare terrestrial plants and insects, as discovered through work done by the Fenland Flora Project and Buglife in the area.


(Botaurus stellaris)

A secretive bird, very difficult to see, as it moves silently through reeds at the water’s edge, looking for fish. Its very small, reedbed-dependent population make it an Amber List species.

Common Toad

(Bufo bufo)

Common toads are amphibians, breeding in ponds during the spring and spending much of the rest of the year feeding in woodland, hedgerows and grassland. They hibernate over winter, often under log piles.


(Vanellus vanellus)

A beautiful bird, also known as the peewit in imitation of its display calls, the name lapwing describes its wavering flight. Its black and white appearance and round-winged shape in flight make it very distinctive.

Common Swift

(Apus apus)

Swifts nest in holes, often inside old buildings or sometimes in specially-designed swift nestboxes. So you’ll never see them building a nest outside. In fact, if you can see an obvious nest, it’s definitely not a swift.

Black Poplar Tree

(Populus nigra)

Mature trees grow to 30 metres and can live for 200 years. The bark is dark brown but often appears black, and is thick with numerous fissures and burrs. The leaves have a faint scent of balsam.

Greater Water Parsnip

(Sium latifolium)

Found in wetland areas. Unfortunately greater water parsnip has declined rapidly over the last 200 years due to the drainage of wetlands and loss of habitat.