Centred around the village of New Galloway, 12½ miles (20 km) northwest of Castle Douglas, Galloway Hydro-Electric Power Scheme was the first large-scale hydro-electric power scheme in Scotland. Construction began in 1929 and the scheme was fully operational by 1935. The design was the work of William McLellan (1874 - 1934) and Sir Alexander Gibb and Partners. This is a relatively modest scheme compared to those of the Highlands, with a total power generation capacity of 109 megawatts (MW). Making use of water principally stored in Loch Doon, Clatteringshaws Loch and Loch Ken, the scheme includes eight dams, 7½ miles (12 km) of tunnels, aqueducts and pipelines together with six power stations at Carsfad (12 MW, commissioned in 1936), Drumjohn (2.25 MW, commissioned 1984), Earlstoun (14 MW, commissioned 1936), Glenlee (24 MW, commissioned 1935), Kendoon (24 MW, commissioned 1936) and Tongland (33 MW, commissioned 1935). The scheme is run remotely by a computerised control system based at the Glenlee Power Station, which is located 1¼ miles (2 km) west southwest of St John's Town of Dalry. There is a visitor centre at the Tongland Power Station, 2 miles (3 km) north of Kirkcudbright.
The scheme is owned and operated by Scottish Power, a privatised utility which now forms part of a multi-national energy group.