Waiau River is the largest river in the Southland Region

Southland Region

Southland is New Zealand's southernmost region and is also a district within that region. It consists mainly of the southwestern portion of the South Island and Stewart Island / Rakiura...

 of New Zealand

New Zealand

New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...

. It is the outflow of Lake Te Anau

Lake Te Anau

Lake Te Anau is in the southwestern corner of the South Island of New Zealand. Its name was originally Te Ana-au, Maori for 'The cave of swirling water'. The lake covers an area of 344 km², making it the second-largest lake by surface area in New Zealand and the largest in the South Island...

, flowing from it into Lake Manapouri

Lake Manapouri

Lake Manapouri is a lake in the South Island of New Zealand. Its name is Maori for "sorrowful heart", though this name is misapplied due to an early cartographical error...

 10 kilometres to the south, and from there flows south for 70 kilometres before reaching the Foveaux Strait

Foveaux Strait

Foveaux Strait separates Stewart Island/Rakiura, New Zealand's third largest island, from the South Island. Three large bays, Te Waewae Bay, Oreti Beach and Toetoes Bay, sweep along the strait's northern coast, which also hosts Bluff township and harbour. Across the strait lie the Solander...

 eight kilometres south of Tuatapere

Tuatapere

Tuatapere is a small rural town in Southland, New Zealand . It is located eight kilometres from the southern coast. The Waiau River flows through the town before reaching Te Waewae Bay, where it has its outflow into Foveaux Strait...

. It also takes water from Lake Monowai

Lake Monowai

Lake Monowai is a large lake in the southern part of Fiordland National Park, in New Zealand's South Island, 120 kilometres northwest of Invercargill. At an altitude of 180 metres in a long curved valley, the lake appears on maps shaped like a letter "U". The western part of the lake is set in...

.

The Upper Waiau River that flows between Lakes Manapouri and Te Anau doubled as the fictional River Anduin

Anduin

In J. R. R. Tolkien's fictional Middle-earth, Anduin is the Sindarin name for the Great River of Wilderland, the longest river in the Third Age . The ancestors of the Rohirrim called it Langflood. It flowed from its source in the Grey and Misty Mountains to the Mouths of Anduin in the Great Sea...

 at the end of the first film of the The Lord of the Rings film trilogy

The Lord of the Rings film trilogy

The Lord of the Rings is an epic film trilogy consisting of three fantasy adventure films based on the three-volume book of the same name by English author J. R. R. Tolkien. The films are The Fellowship of the Ring , The Two Towers and The Return of the King .The films were directed by Peter...

, for the scenes where the Uruk-hai

Uruk-hai

The Uruk-hai are fictional characters in J. R. R. Tolkien's fictional universe of Middle-earth. They are introduced in The Lord of the Rings as an advanced breed or breeds of Orcs that serve Sauron and Saruman...

 chase the Fellowship along the river banks. A proposal that a two km stretch of river below the area known as Balloon Loop be named the Anduin Reach

Anduin Reach

The Anduin Reach, an unofficial name for a section of the Upper Waiau River, Southland, is in the South Island of New Zealand. It is part of a river system that feeds from Lake Te Anau and discharges into Shallow Bay eighteen kilometres downstream from where it leaves Lake Te Anau. Water at the...

 to honour New Zealand film maker Peter Jackson

Peter Jackson

Sir Peter Robert Jackson, KNZM is a New Zealand film director, producer, actor, and screenwriter, known for his The Lord of the Rings film trilogy , adapted from the novel by J. R. R...

 for his use of the area as the River Anduin was rejected by the New Zealand Geographic Board

New Zealand Geographic Board

The New Zealand Geographic Board is constituted under the New Zealand Geographic Board Act 2008, formerly under the New Zealand Geographic Board Act 1946. Although an independent institution, it is responsible to the Minister for Land Information...

 in April 2009.

Flora and fauna

There are diverse species in the forested catchment basin of the Waiau River. Vegetative understory within most of the Fiordland National Park

Fiordland National Park

Fiordland National Park occupies the southwest corner of the South Island of New Zealand. It is the largest of the 14 national parks in New Zealand, with an area of 12,500 km², and a major part of the Te Wahipounamu World Heritage site...

 includes numerous fern species including the Crown Fern, Blechnum discolor

Blechnum discolor

Blechnum discolor is a species of fern in the family Blechnaceae. This species is endemic to New Zealand. As noted by C. Michael Hogan, this species is found in a number of forest communities in diverse locations within New Zealand, and is sometimes a dominant understory component.Spores are...

.

Several species of endangered birds live around the shores of Lake Te Anau, and the upper Waiau River, notably the Takahē

Takahe

The Takahē or South Island Takahē, Porphyrio hochstetteri is a flightless bird indigenous to New Zealand and belonging to the rail family. It was thought to be extinct after the last four known specimens were taken in 1898...

 (Notornis hochstetteri). An area between the Middle and South Fiords called the Murchison Mountains is a sanctuary set aside for these birds. The western shore of Lake Te Anau also holds the Te Ana-au Caves

Te Ana-au Caves

The Te Ana-au caves are a culturally and ecologically important system of limestone caves on the western shore of Lake Te Anau, in the southwest of New Zealand. It was discovered in 1948 by Lawson Burrows, who found the upper entry after three years of searching, following clues in old Māori legends...

, from which Lake Te Anau derives its name.