The Clutha River / Mata-Au is the second longest river in New Zealand flowing south-southeast 338 kilometres (210 mi) through Central and South Otago from Lake Wanaka in the Southern Alps to the Pacific Ocean, 75 kilometres (47 mi) south west of Dunedin. It is the highest volume river in New Zealand, and the swiftest, with a catchment of 21,960 square kilometres (8,480 sq mi), discharging a mean flow of 614 cubic metres per second (21,700 cu ft/s).
The Clutha River is known for its scenery, gold-rush history, and swift turquoise waters. A river conservation group, the Clutha Mata-Au River Parkway Group, is working to establish a regional river parkway, with a trail, along the entire river corridor. The name of the river was changed to a dual name by the Ngai Tahu Claims Settlement Act 1998.
The ultimate source of the river is at the head of the Makarora River, close to the saddle of the Haast Pass, which flows into the northern end of Lake Wanaka. The southern end of the lake drains into the nascent Clutha close to Albert Town, where it is met by its first main tributary, the Hawea River the outflow of Lake Wanaka's twin, Lake Hawea. It is also met here by the Cardrona River.
From here the river flows swiftly through the Upper Clutha Valley between ancient glacial terraces, negotiating a long section called the 'Snake' before reaching a rare switchback feature called the Devil's Nook near the town of Luggate. The river soon narrows as it passes through the Maori Gorge at Queensberry. Shortly thereafter it is joined by another tributary, the Lindis, before widening as it enters Lake Dunstan, an artificial lake created behind the massive hydroelectric dam at Clyde.
Fifty kilometres south of Lake Wanaka, the Clutha reaches the town of Cromwell, which was substantially altered when the Clyde Dam project was commissioned in 1992. Here the river is joined by the waters of the Kawarau, which flows from Lake Wakatipu. Prior to the construction of the Clyde Dam, this river junction, known as the Cromwell Junction,was renowned for the difference in colour between the two rivers’ waters.
River then flows southeast through the inundated Cromwell Gorge to Clyde, and nearby Alexandra, where it is joined by the waters of the Manuherikia River. South of Alexandra the river widens again to form Lake Roxburgh, another artificial lake, behind the Roxburgh Dam, which was commissioned in 1956. The hydro reservoir flooded the Roxburgh Gorge and several large rapids including the Molyneux Falls and the Golden Falls. The town of Roxburgh sits close to the river, 120 kilometres (75 mi) downstream from Lake Wanaka.
Country: New Zealand
Discharge: 614 m³/s
Source: Makarora River
Mouth: Pacific Ocean
Bridges: Balclutha Road Bridge
Cities: Alexandra, Cromwell, Roxburgh, Clyde, Luggate, Millers Flat, Beaumont, Ettrick
Length: 338 km (210 mi)
Mouth elevation: sea level
Avg. discharge: 614 m3/s (21,700 cu ft/s) at mouth
Basin area: 21,960 km2 (8,480 sq mi)