The Wayatinah Dam is a rock-filled embankment dam with earthen core across the Lower River Derwent, located near the small settlement of , in the Central Highlands region of Tasmania, Australia. Completed in 1983, the resultant reservoir, Wayatinah Lagoon, was established for the purpose of generation of hydroelectricity via the adjacent Wayatinah Power Station, a run-of-the-river hydroelectric power station.
The dam, its reservoir, and the power station are owned and operated by Hydro Tasmania. The etymology of the word wayatinah is derived from a Tasmanian Aboriginal word meaning "brook" or "stream".
Dam and reservoir overview The rockfill dam wall is high and long. When full, the Wayatinah Lagoon has capacity of and covers , drawn from a catchment area of . The uncontrolled spillway has a flow capacity of .
Hydroelectric power station Part of the Derwent scheme that comprises eleven hydroelectric power stations, the Wayatinah Power Station is the sixth power station in the scheme and the second power station in the lower run-of-river system. The aboveground power station is located on the Derwent, below its junction with the Nive River. Water from the Derwent from Liapootah Power Station and spill from Liapootah Dam flows into Wayatinah Lagoon. Water in the lagoon is diverted by a -long tunnel to two low pressure woodstave pipelines, each long. It then descends through three steel penstocks to the Wayatinah Power Station. The tunnel intake structure is provided with two vertical lift, gravity close intake gates designed to cut off full flow. Each of the three steel penstocks is provided with a hilltop valve designed to close under full flow.
The power station was commissioned in 1957 by the Hydro Electric Corporation (TAS) and the station has three English Electric Francis turbines, with a combined generating capacity of of electricity. Within the station building, each turbine has a fully embedded spiral casing and water flow is controlled by a spherical rotary main inlet valve and a turbine relief valve designed to prevent spiral casing overpressure. The station output, estimated to be annually, is fed to TasNetworks' transmission grid via an 11 kV/220 kV three-phase English Electric generator transformer to the outdoor switchyard. An 11 kV indoor switchgear system also supplies a distribution yard that supplies power to the local area from Wayatinah village to and includes the power stations of Liapootah, Wayatinah, Catagunya, Repulse and Cluny.
See also
List of power stations in Tasmania List of reservoirs and dams in Tasmania List of run-of-the-river hydroelectric power stations
References
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