See also River Severn on Wikipedia, and the disclaimer.

Severn (sĕv′ẽrn), the second largest river of England, rises in Wales and after 210 miles falls into Bristol Channel. It is navigable for 180 miles; a canal has helped navigation from Gloucester, and is now being extended to Worcester. Below Gloucester the swiftly flowing tide produces a bore or wave five or six feet high. The Severn is a beautiful as well as an important river.