Severn Estuary

Welcome to the Severn estuary! At around 24700ha, it isone of the largest estuaries in Britain and has the secondlargest tidal range in the world. It forms the border between Wales and England in south-west Britain at themouth of three major rivers; the Severn, Wye and Avon. We hope this leaflet helps you to enjoy the estuary, and at the same time understand more about the wildlife youshare it with.

Natural History and conservation

The inter-tidal zone of mudflats, sandbanks, rockyplatforms and saltmarsh is one of the largest and mostimportant for wildlife in Britain.

The extreme conditions created by mud, sand and rock can only be tolerated by a few plants and animals. However there are high densities of ragworms and lugworms whichare an important food source for migrating andoverwintering waders.

Saltmarsh, the upper part of intertidal mudflats, is foundall along the estuary’s fringes in Avon. Only a limitednumber of salt tolerant plants can grow in theseconditions, including nationally scarce species such asslender hare’s-ear, sea clover and bulbous foxtail.Saltmarsh also provides important feeding and roostingareas for waterfowl and waders.

Over winter, the area regularly supports about 85,000 waterfowl including shelduck, wigeon, teal, grey plover, lapwing, dunlin, redshank and curlew. Bewick’s swan,white-fronted goose, pintail, gadwall and pochard alsooccur. Whimbrel and ringed plover pass through in large numbers on migration, the former particularly in spring. The river also attracts migratory fish species such assalmon, sea trout, twaite and allis shad.

The wild bird populations are of European importance,and the estuary is classified as a Special Protection Areaand Ramsar site. Most of the estuary is also designated asa Site of Special Scientific Interest (SSSI) and is beingconsidered as a Special area of Conservation (SAC).

For further information

Download the full PDF guide here

Find out more about the Avon Biodiversity Partnership here:

Energy at any price? Severn Barrage Report launched

The Wildlife Trusts’ report - Energy at any price? highlights the vital importance of the Severn Estuary. Not just for wildlife but people too. As the Government considers different proposals for harnessing the immense natural tidal power to create electricity, The Wildlife Trusts say damming the Estuary with an old-fashioned barrage would have a devastating impact. Instead, the Government should commit to investigating a range of modern, low-impact technologies.

Download the report here