Clutha

Geography

The Clutha River is the South Island's largest river and has the largest catchment and outflow in New Zealand. About 6% of all water in the South Island is discharged through Clutha River alone. It has a mean discharge of approximately 500 m3 (18,000 cu ft), a catchment area of around 22,000 km2 (8,500 sq mi), and a length of about 340 km (210 mi), which makes it one of the longest rivers in New Zealand. The major tributaries include the Arrow River, Cardrona River, Lindis River, Manuherikia River, Teviot River, Pomahaka River, and the Waitāhuna River. Towns near the Clutha River include Alexandra, New Zealand, Balclutha, Cromwell, Roxburgh, and Wānaka.

The Clutha River extends about 340 km (210 mi), flowing roughly north to south through the Otago Region.

History

Māori occupation of the Otago Region began in c. 1250–1300. Māori learned to hunt the numerous species of moa and burned many of the inland forests. The first iwi in Otago were Waitaha, then Kāti Māmoe; later came Kāi Tahu. By the end of the fourteenth century, the environment in Otago and Southland (Murihuku) had begun to shift, with podocarp woods retreating and the moa population declining. A few Māori settlements in the region started to lose importance, although several settlements still existed in Central Otago.

Ecology

A 2022 report on Clutha freshwater fishes below Roxburgh by the National Institute of Water and Atmospheric Research (NIWA) documented 14 species of native fish, 11 of which are diadromous (including the giant kōkopu and kōaro), meaning that they have marine migratory phases. Additionally, the Clutha River has an unusually high diversity of non-migratory fish species in its tributaries. Brown trout are the most encountered fish in the Clutha River, occurring throughout the main river, streams, and nearby lakes. Rainbow trout also appear in the river but in smaller numbers, and they are more common in the lower section of the river compared to the upper stretches.