Cornmill Stream and Old River Lea

Also within

Essex County

Condition (Natural England)

Habitats

Fast flowing river and stream

Description

Area,24.6 hectares 60.5 ac Description Cornmill Stream and the Old River Lea form a freshwater habitat with one of the most diverse invertebrate faunas in Essex. The site supports an outstanding assemblage of dragonflies and damselflies. Odonata; eighteen species have been recorded, including two notable scarce species. The slow moving streams support a rich and varied aquatic and marginal flora. Associated with this habitat is one of the richest gastropod molluscan faunas in the county including two vulnerable species of freshwater snail and other invertebrates including a rare sawfly and a rare soldier fly. The Old River Lea is one of only two known localities in Essex for the uncommon and nationally declining white legged damselfly Platycnemis pennipes. Other Odonata include the variable damselfly Coenagrion pulchellum, the red eyed damselfly Erythromma najas and the ruddey darter Sympetrum sanguineum. The botanical interest lies in the diversity of aquatic plants. Emergents include stands of flowering rush Butomus umbellatus and common club rush Schoenoplectus lacustris, both declining species in Essex. The floating vegetation includes the yellow water lily Nuphar lutea, shining pondweed Potamogeton lucens and amphibious bistort Polygonum amphibium. The site also includes an area of rough grassland which provides feeding and breeding grounds forboth invertebrates and birds.

Species mentioned

Plant communities