The River Derwent begins its journey at Lake St Clair and flows in a south-easterly direction.
The harnessing of the hydro-electric potential of the Derwent River began in 1934 when the Hydro-Electric Corporation began construction of the Tarraleah Power Development. The last power stations on the river were commissioned in 1968.
To fully use the water in the Derwent River a number of separate developments were required. They included the construction of 16 dams, 10 power stations and a number of weirs, canals, flumes, tunnels and pipelines.
The overall plan of the development takes the shape of a large Y which is tilted on its side. The arm which points west contains the Butlers Gorge Power Station with Tarraleah at its eastern edge. The northern arm contains Lake Echo Power Station and has Tungatinah at its base. The leg of the Y has a series of six power stations, with the last one, Meadowbank, about 80 km from Hobart. The 10 power stations have a total capacity of 515 MW (megawatts).
Water which originates at an altitude of 846 metres around Lake Echo and 737 metres at Lake St Clair flows out of Meadowbank Power Station only 44 metres above sea level.
The 10 power stations produce about 27% of Tasmania's electricity.
More details on the Derwent catchment.