Many of the reservoirs and dams in New Zealand have been developed principally to produce hydroelectricity.

Hydro-electric Dams

The main river systems comprising a series of dams and powerhouses are situated on the following rivers:

The Waikato River

The Waitaki River

The Clutha River

Other schemes are standalone developments associated with specific sites.

Tongariro Power Scheme

The Tongariro Power Scheme (1,400 GWh) diverts water from the south side of Mount Ruapehu and Tongariro into Lake Taupo.

• Rangipo (underground cavern) (120 MW)
• Tokaanu (240 MW)

The Waikato

The hydro stations, starting from Lake Taupo, are (capacity in MW and nominal annual energy output in GWh):

• Aratiatia (84 MW) (331 GWh)
• Ohakuri (112 MW) (400 GWh)
• Atiamuri (84 MW) (305 GWh)
• Whakamaru (100 MW) (486 GWh)
• Maraetai (360 MW) (855 GWh)
• Waipapa (51 MW) (330 GWh)
• Arapuni (171 MW) (805 GWh)
• Karapiro (90 MW) (490 GWh)

The Waitaki

The river is developed in two areas - The upper Waitaki and the mid Waitaki. There are two dams on the upper Waitaki, the Pukaki high dam and the Ruataniwha dam. In the upper Waitaki, water is passed from storage lakes through canals to each power station.

The stations are:

• Tekapo A (25 MW) (160 GWh)
• Tekapo B (160 MW) (800 GWH)
• Ohau A (264 MW) (1150 GWh)
• Ohau B (212 MW) (970 GWh)
• Ohau C (212 MW) (970 GWh)

The mid Waitaki power stations discharge water back into the Waitaki River which then forms a storage lake for the next station in the chain. The three power stations are:

• Benmore (540 MW) (2,200 GWh)
• Aviemore (220 MW) (900 GWh)
• Waitaki (105 MW) (500 GWh)

Project Aqua was a proposed scheme of 6 dams on a man made canal running from the Waitaki Dam to the sea. It was cancelled by Meridian Energy Limited on 29 March 2004.

see also Lake Benmore, Lake Aviemore, Lake Ruataniwha, and Lake Waitaki

Clutha River

• Clyde Dam (445 MW)
• Roxburgh Dam

Standalone Hydro schemes

• Manapouri (850 MW) (4,800 GWh)

Manapouri does not rely on a high dam to provide water - it takes advantage of the natural 178-metre height difference between Lake Manapouri and the sea at Deep Cove in Doubtful Sound, in Fiordland. The power house is in an underground cavern, while two tailrace tunnels take the water from the power house 10 km to Deep Cove and the sea. The Manapouri Control Structure (Mararoa dam) downstream from the original outlet of Lake Manapouri controls the lake level, and feeds water from the Mararoa river back up the river into the Lake.

Other Schemes in the North Island

• Kaimai Scheme - Kaimai (0.4 MW), Lloyd Mandeno (15.6 MW), Lower Mangapapa (6.25 MW), Ruahihi (20 MW) - Scheme: (165 GWh)
• Matahina Dam (36 MW) (300 GWh) - Bay of Plenty
• Lake Waikaremoana Scheme - 3 Dams: Kaitawa (36 MW), Tuai (60 MW), and Piripaua (42 MW).
• Wheao & Flaxy (26 MW) (115 GWh)
• Hinemaiaia - A (2.25 MW), B (1.35 MW), C (2.85 MW) - (30 GWh) - near Taupo
• Motukawa (4.6 MW) (25.8 GWh) - Taranaki
• Mangorie (4.5 MW) (20.9 GWh) - Taranaki
• Patea Dam (31 MW) (115 GWh) (Peak Station) - Taranaki
• Mangahao (30 MW) - Tararuas
• Kourarau Scheme (1 MW) - Wairarapa

Other Schemes in the South Island

• Waihopai (2.5 MW) (11.8 GWh)
• Branch River - (Wairau & Argyle Stations) (11 MW) (54.3 GWh) - Run of River canals.
• Cobb Dam (32 MW) - Golden Bay
• Arnold Dam (3 MW) (25 GWh) - West Coast
• Dillmans (0.5 MW), Duffers (3.5 MW), Kumara (6.5 MW) - Scheme: (47.9 GWh)
• Kaniere Forks (0.43 MW) (3.75 GWh) & MacKays Creek (1.1 MW) (8 GWh)
• Wahapo (3.1 MW) (14.5 GWh) - South Westland
• Lake Coleridge (45 MW) (205 to 300 GWh) - Canterbury - Diverted rivers and natural lake.
• Highbank (25.2 MW) (115 GWh) - Canterbury - joint power & irrigation.
• Montalto (1.1 MW - 1.8 MW) (12 GWh) - Canterbury - joint power & irrigation.
• Opuha Dam (7.5 MW) - Canterbury - joint power & irrigation.
• Paerau & Patearoa (10 MW) (50 GWh) - Taieri River, Otago - joint power & irrigation.
• Waipori - 4 Dams (12 MW, 57 MW, 7 MW, 8 MW) - Dunedin
• Monowai (6 MW) (34 GWh)

Water Supply Dams

• Huia Dam - Auckland
• Hunua Dam - Auckland
• Macaskill Lakes - Upper Hutt
• Opuha Dam - New Zealand. Also has a small hydro-electric scheme (7.5 MW).

Defunct Water Supply Dams

• Birchville Dam - Upper Hutt
• Karori Reservoir - Wellington (now a nature reserve)

Irrigation dams

• Lakes Manuwai and Waingaro at Kerikeri, purpose-built irrigation dams containing 12,800,000 m3 of water

See also

List of rivers of New Zealand

External Links

• Conventional Hydroelectric Power Plants in New Zealand
• Trustpower Generation - November 2001 Report (PDF)
• Waikato Hydroelectric Scheme