Claerwen

The Claerwen reservoir and dam in Powys, Wales, were the last additions to the Elan Valley Reservoirs system built to provide water for the increasingly demanding city of Birmingham, in neighbouring England. Built mainly of concrete, the exterior of the dam face is dressed stone. The dam itself is of a type called a gravity dam. This type of dam needs to be built upon solid foundations as the pressure of the reservoir behind should be in equilibrium with the total weight of the dam itself thus causing complete stability.