Errochty Dam Including Tunnel Intake Gatehouse, Tummel Garry Hydro Electric Scheme

Errochty Dam, part of the Tummel Garry Hydro Electric Scheme, was designed by Sir Alexander Gibb and Partners and constructed by A and A Carmichael in 1956. This large diamond-headed buttress dam features an access roadway that oversails the central spillway, with a separate intake gatehouse located upstream of the dam wall, which dominates the upper Glen Errochty. The dam is primarily made of shuttered concrete, with some reinforced concrete used for the intake gatehouse.

The downstream face of the dam is battered and supported by deep buttresses, which flank the spillway and are integrated with the spillway walls at the base of the dam. A large buttress is positioned at the center of the spillway, housing a small control room and a dispersal valve at the base. The square-plan gatehouse is integrated at an upper level on the upstream side of the dam. There is also a small control room located at the base of the buttress to the northeast of the spillway, which includes a pipeway control valve.

The parapet at the top of the dam extends slightly beyond the roadway and is integrated with the buttresses. The roadway is supported by rectangular concrete piers and features a design similar to that of the upstream face.

The tunnel intake gatehouse is situated adjacent to the upstream face of the dam. It is a tall, two-storey square-plan structure set on a podium, with vehicular access that oversails the water on round concrete columns. The south elevation has large panelled teak vehicular access doors, along with three small windows in the attic storey above. Similar windows are found on the west and north elevations. The east elevation features a pedestrian doorway with louvered vents to the left and a pair of tall windows above, along with small paired windows in the attic.