River Etherow

The River Etherow is a river in northern England, and a tributary of the River Goyt. Although now passing through South Yorkshire, Derbyshire and Greater Manchester, it historically formed the ancient county boundary between Cheshire and Derbyshire. The upper valley is known as Longdendale. The river has a watershed of approximately 30 square miles (78 km2), and the area an annual rainfall of 52.5 inches (1,330 mm).