Commissioned in 1932, the plant is rated at 3 megawatts (4,000 hp) and has an average annual output of 25 gigawatt-hours (90 TJ).

However, to meet pressing demands for electricity supply from local residents this plan was postponed, and a coal-burning steam engine power station was built at Dobson in 1926.

[2] However, after only a year's operation, the level of demand was such that more capacity was required, and the planning for the Arnold River hydro scheme recommenced.

[2] TrustPower had been planning a new hydroelectric power station at Arnold, with an output of 46 megawatts (62,000 hp) and average annual generation of 220 gigawatt-hours (790 TJ).

[5] Though the resource consents were upheld by the Environment Court in 2010,[1] the project was put on hold indefinitely in 2012 due to changes in economic conditions.