Construction of the Derwent hydropower scheme began in 1934 and the last power station was commissioned in 1968.
There are two sections in the Derwent hydropower scheme – the upper and lower. This is because of the difference in how the water is stored in the sections. Visually the scheme resembles a Y shape.
The upper section of the scheme uses larger, deeper lakes for water storage than the lower section. The four main power stations in the upper section release water when it is needed to generate electricity. The upper section is formed from the Nive River system in the east and the Derwent River system in the west, making up the top of the Y.
The lower section is called run-of-river, which means water flows to power stations directly from a river, and cascades through a series of power stations. This means the same water is used to generate energy multiple times. There are six power stations in the lower section and they use water from the Derwent River multiple times. The lower section forms the ‘tail’ of the Y.
The power station is supplied by the water stored at Lake King William. Water then flows to Tarraleah Power Station.
Nieterana is the Aboriginal name for little brother. This mini-hydro station sits alongside ‘big brother’ Butlers Gorge Power Station and was commissioned in 2004. When additional turbines were added to Tarraleah Power Station, a second canal needed to be built to carry enough water from Lake King William to make full use of all turbines. Nieterana was built at the base of Lake King William to make use of the water flowing through the second canal.
Water from Wayatinah Lagoon flows through to Wayatinah Power Station, continuing to Lake Catagunya.