The Severn ea (Welsh: Afon Hafren) is the longest ea in England (though it rises in Wales). The towns of Shrewsbury, Worcester and Gloucester sit on its banks. The Severn becomes the Bristol firth as it nears the Irish sea and the Atlantic sea.
The Severn is also England's greatest ea by flow, at 107 m3/s. Its watershed is 11,420 km2.