04 December 2008

Environment Agency - Home

About the Severn Estuary

The Severn Estuary is Britain’s second largest estuary. It covers 55,7000ha including 20,000ha of inter-tidal habitat and a 14.5 tidal range. Its combination of immense tidal range and classic funnel shape make it unique in the UK and rare worldwide. The Severn and its 10 sub-estuaries represent about seven percent of the UK total estuary resource.

Its environment

  • The Severn Estuary provides a vital link in bird migration routes between Africa and Siberia and supports both an over-wintering bird population itself and provides a stop over for passing migratory species. It regularly supports over 60,000 over wintering wildfowl, including over 50% of the British population of European white-fronted geese, 10% of dunlin and 5% of several other species.

  • Twenty five percent of the England and Wales salmon spawning area is found in the rivers running into the Severn Estuary. The Wye being the most important river in England and Wales on this basis. Of the four rivers in the UK that support spawning populations of twaite shad, three (the Severn, Wye and Usk) drain into the estuary. The estuary and its tributary rivers also support internationally important populations of eel, river and sea lamprey.