The Severn rises in Wales on Plynlimmon at an altitude of 1500 feet on the border of Montgomeryshire
and flows northeast and east to Shrewsbury
in England, southeast through Shropshire
, and then southwest to Gloucester
, below which it forms an estuary opening into the Bristol Channel after a total course of 210 miles.
The Severn receives the Teme, Wye, and Usk on the right and the Vyrnwy, Stour, Tern and Upper and Lower Avon on the left.
The Severn has a high tidal bore which sometimes ascends beyond Gloucester and causes considerable destruction.