The reserve consists of floodplains along the River Yare, and the total area is 779 hectares. It centres around the Strumpshaw area.
The alder carr and willow carr support the Swallowtail Butterfly and the Norfolk Hawker dragonfly Aeshna isosceles, as well as Marsh Harriers, Bearded Tits and most of the country's Cetti's Warblers.
The wet grasslands hold internationally important numbers of wigeon, nationally important numbers of European White-fronted Goose, and Britain's largest flock of Bean Goose, as well as Lapwing, Redshank and Snipe.
The RSPB controls the water levels, maintains the dykes, cuts the reedbedsbeds and keeps disturbance of the wildlife to a minimum.