A substantial loch at an altitude of 351m (1153 feet) above sea-level in the Grampian Mountains, Loch Ericht straddles the boundary between Highland and Perth and Kinross Council Areas. It occupies a valley that is aligned northeast to southwest and measures 14½ miles (23 km) in length and about three-quarters of a mile in width. With a surface area of 18.6 sq. km (7.2 sq. miles), Loch Ericht is the tenth largest freshwater loch in Scotland. Ben Alder rises to 1148m (3757 feet) to the west and at its northern end is the village of Dalwhinnie. The loch was dammed at both ends in 1931 to create a reservoir, now part of the Tummel Hydro-Electric Power Scheme. It receives the water from the Cuaich Aqueduct at its northern end while the southern end of the loch is linked to a power station on Loch Rannoch by the 4-mile (6.5-km) long River Ericht.