Laggan Dam

Laggan Dam is a dam located on the River Spean south west of Loch Laggan in the Scottish Highlands.HistoryThe structure was built by Balfour Beatty for the British Aluminium Company and construction was finished in 1934. The supervising engineers were the firm of C S Meik and William Halcrow, now known as the Halcrow Group.The dam was designated a Category B listed building in 1985. It was upgraded to Category A listing in 2011, following a review as part of Hydroelectric Power Thematic Survey 2010.DesignThe dam is about long, and high between the level of the foundations and the crest of the spillway. It is curved upstream like an arch dam with a radius of curvature of, but works purely on the principle of a gravity dam.The whole crest of the dam, except for a section in the middle that houses equipment, is a spillway broken into 29 bays by piers that support a roadway across the dam. As well as the spillway, there are six pipes embedded into the centre of the dam, controlled automatically by system of air valves. The foundations are built on granite, and the dam was built in seven sections, with copper strip and hot poured asphalt water stops in the joints.The dam contains Loch Laggan, which has a capacity of.