Tongariro National Park - Tongariro Power Scheme

Tongariro Power Scheme

The Tongariro Power Scheme was designed to preserve and protect the natural surroundings as much as possible. It gathers water from the mountains of the central volcanic plateau, passes it through Rangipo (120MW) and Tokaanu (240MW) power stations, and releases it into Lake Taupo. The scheme taps a catchment area of more than 2600 km² and uses a series of lakes, canals and tunnels to take water to the two stations which typically generate 1400 GWh pa,. about four percent of the country's total electricity generation. The extra catchment increases the volume of water going into Lake Taupo and down the Waikato River by 20%.

The western diversion takes water from six rivers and streams from the Whakapapa River to the Whanganui River, into Lake Rotoaira via Lake Otamangakau. The Tokaanu power station is connected to Lake Rotoaira via a six kilometre tunnel through Mount Tihia. It also draws water from the Tongariro River via the Poutu tunnel and canal.

On the eastern side of Mount Ruapehu, water is diverted from the Kaimanawa Ranges and headwaters of the Wahianoa River through a 20 km tunnel into the Rangipo dam. The 120MW Rangipo power station is 230 m below ground. Its turbines are located in a cavern cut from solid rock and lined with concrete. Genesis Energy has developed mitigation measures with stakeholders that aim to lessen the environmental effects of the Tongariro Power Scheme.

Some of these measures include lake level management, ecological monitoring programmes, and agreements with local iwi to establish a process for iwi involvement in environmental monitoring and access to information. The electricity generated at the Tongariro Power Scheme goes into the national grid. Then it is distributed to residential, commercial and industrial customers throughout New Zealand.