Lake Lapworth

Lake Lapworth was a postulated glacial lake in Great Britain, believed to have formed during the last ice age when glaciers ended the northern outlet of the Severn. This ran through the Dee (which passes by Chester). At some point or points it ran into glaciers and backed up to form a resultant lake. This overflowed southwards cutting the Ironbridge Gorge, near Telford in Shropshire. This permanently diverted most of the Severn drainage basin to its current basin which flows south.