Structure

Ohakuri has an earth dam with concrete gravity sections for the intake and spillway structures. Steel penstocks lead from the intake to the four Francis turbines in the powerhouse. An auxiliary turbine takes water through a dedicated penstock to generate electricity for the station.

The powerhouse lies below the dam on the left bank. For 1 MW of electricity to be generated at this station, 3.6 tonnes of water every second is required. Each of the four generators produces electricity at 11,000 volts. Transformers step up the voltage to 220,000 volts for transmission over the national grid.

An open concrete spillway sweeps around the right end of the dam and down to the river below. A special feature is the fantail-shaped outlet which throws the water in a high, wide arc to minimise any erosion while the gates are open. Like all the power stations on the Waikato River Ohakuri is remotely operated from our control room in Hamilton which monitors, controls and co-ordinates the output of each station on the river.