At 220 miles (354 km) long, the River Severn is the longest river in Great Britain. River Severn has the highest water flow in England and Wales at 107 m3/s in Gloucestershire.
The River Severn originates from Plynlimon massif in mid Wales at 610 m above sea level near Llanidloes. The river then flows through Shropshire, Worcestershire and Gloucestershire. On its course lie the counties of Shrewsbury, Gloucester and the city of Worcester.
The main tributaries of the Severn are the Vyrnwy, Tern, Teme, Warwickshire Avon and Worcestershire Stour.
The river is usually considered to end and the estuary to begin after the second crossing of the Severn between Severn Beach in South Gloucestershire and Sudbrook in Monmouthshire.
Etymology and Mythology
Name Severn is thought to derive from the British *sabrinā, possibly from an older form of *samarosina, meaning „land of summer eel“. The name is recorded in the 2nd century in the Latinized form Sabrina.
The Welsh form of the name is Hafren, first recorded in the 12th-century Historia Regum Britanniae. In Milton’s 1634 mask of Comus, Sabrina is a nymph who drowned in a river. Shrewsbury now has a statue of Sabrina in Dingle Quarry Gardens, as well as a metal statue erected in 2013.
Wildlife of the Severn
Banks of the estuary are also an important foraging habitat for waders, particularly at Bridgwater Bay National Nature Reserve and Slimbridge Wildfowl Trust reserve. The lower estuary also contains a river shale habitat which is notable for its population of the endangered five-spotted barnacle.
The river is part of the Severn-Trent Flyway, a route used by migratory birds to cross the UK.
