Waitaki River

The Waitaki River is a large river in the South Island of New Zealand, some 110 km long. It is the major river of the Mackenzie Basin. It is a braided river which flows through Lake Benmore, Lake Aviemore and Lake Waitaki. These are ultimately fed by three large glacial lakes, Pukaki, Tekapo, and Ohau. Lake Benmore and Lake Aviemore are contained by hydroelectric dams, Benmore Dam and Aviemore Dam.

The Waitaki has several tributaries, notably the Ahuriri River and the Hakataramea River. It passes Kurow and Glenavy before entering the Pacific Ocean between Timaru and Oamaru on the east coast of the South Island.

The river’s flow is normally low in winter, with flows increasing in spring when the snow cloaking the Southern Alps begins to melt, with flows throughout the summer being rainfall dependent and then declining in the autumn as the colder weather begins to freeze the smaller streams and streams which feed the catchment. The median flow of the Waitaki River at Kurow is 356 cubic metres per second.

The middle of the river bed forms a political boundary between the Canterbury and Otago regions. As such, the term "South of the Waitaki" is often used to refer to the Otago and Southland regions as one common area (the two regions share historical and ethnic relationships which make them distinct from the regions to the north of them).

In 2001 a proposal for a series of canals and dams was made by Meridian Energy for irrigation and electricity generation on the river. This scheme, known as Project Aqua, planned to divert up to 77% of the lower river's flow to create a hydroelectric scheme, but these plans were dropped in March 2004. Lack of commercial viability was given as the major reason for the scheme's shelving, although strenuous public protest may also have been a major contributing factor, but a more modest successor scheme, the North Bank tunnel looks likely to proceed, with water rights being granted in September 2009.

The river is popular for recreational fishing and jetboating.