Many of the largest dams and reservoirs in New Zealand have been developed principally to produce hydroelectricity. Other uses include irrigation and municipal water supply.

Hydro-electric dams

The main river systems comprising a series of dams and powerhouses are situated on the following rivers: 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 the west and north sides of Tongariro into Lake Taupō, and thus eventually into the Waikato River.

The Waikato

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

The Waitaki

The river was developed in multiple stages. The Waitaki Dam was built first, without earthmoving machinery, followed by the development of the Aviemore Dam on Lake Aviemore and Benmore Dam on Lake Benmore. Lake Pukaki was initially dammed at this stage to provide storage and flow control. A small station was also installed on Lake Tekapo, but although it has a small dam to raise the pre-existing lake, water was taken through a 1.6 km tunnel to a powerstation below the level of the lake. In the 1960s, work was started on the Upper Waitaki project. This project consisted of taking the discharge from the original Tekapo (A) station through a power canal, the Tekapo Canal, to Tekapo B station at the edge of Lake Pukaki. The dam at Pukaki was increased in height. Water from Pukaki is then transferred into the Pukaki Canal which meets the Ōhau Canal from Lake Ōhau into Ōhau A station and Lake Ruataniwha. The Ōhau Canal continues beyond Lake Ruataniwha to Ōhau B midway along, before emptying through Ōhau C into Lake Benmore. The stations are (capacity) (annual output) (commissioned) The original 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: Project Aqua was a proposed scheme of six dams on a man made canal running from the Waitaki Dam to the sea. It was cancelled by Meridian Energy on 29 March 2004.

Clutha River

Standalone hydroelectric schemes

Other schemes

North Island

South Island

Municipal water supply dams

Auckland

Other North Island

South Island

Defunct dams

Irrigation dams