Part of the Derwent scheme that comprises eleven hydroelectric power stations, the Catagunya Power Station is the seventh power station in the scheme and the third power station in the lower run-of-river system. The power station is located above ground, below Lake Catagunya, a small storage created by the rock-filledCatagunya Dam on the Derwent River 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 2-kilometre (1.2 mi)-long tunnel to two low pressure woodstave pipelines, each 1.3 kilometres (0.81 mi) long. It then descends 56 metres (184 ft) 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.[2][3]
The power station was commissioned in 1962 by the Hydro Electric Corporation (TAS) and the station has two 25-megawatt (34,000 hp) Boving Francis-typeturbines, with a combined generating capacity of 48 megawatts (64,000 hp) of electricity. Within the station building, each turbine has a semi-embedded spiral casing, and water flow is controlled via twin radial gates installed at the entrance to each penstock and designed to cut off full flow. No inlet valves are installed in the station. The station output, estimated to be 237 gigawatt-hours (850 TJ) annually,[1] is fed to TasNetworks' transmission grid via two 11 kV/220 kV ASEA generator transformers to the outdoor switchyard.[2]
