Clewedog Dam
Clywedog Dam is a substantial concrete arch dam in the upper Severn catchment near Llanidloes in Powys, completed in 1967 and creating the Llyn Clywedog reservoir which serves primarily as a regulating reservoir controlling the flow of the River Severn through central and eastern England. At 72 metres the dam is the tallest in England and Wales, and the reservoir it creates holds 50 million cubic metres of water that can be released to maintain minimum flows in the Severn during dry weather. The reservoir and the surrounding upland landscape of the Cambrian Mountains provide scenic walking, cycling and fishing in one of the more remote parts of mid-Wales. The nearby town of Llanidloes is an attractive market town with a remarkable sixteenth-century half-timbered market hall, and the upper Severn valley between Llanidloes and the reservoir provides some of the most undiscovered landscape in mid-Wales.