Rakaia River from Butler Saddle New Zealand Aotearoa

The Rakaia River is in the

Canterbury Plains The Canterbury Plains () are an area in New Zealand centred in the Mid Canterbury, to the south of the city of Christchurch in the Canterbury region. Their northern extremes are at the foot of the Hundalee Hills in the Hurunui District, and in t ...

New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...

South Island The South Island, also officially named , is the larger of the two major islands of New Zealand in surface area, the other being the smaller but more populous North Island. It is bordered to the north by Cook Strait, to the west by the Tasman ...

. The Rakaia River is one of the largest

braided river A braided river, or braided channel, consists of a network of river channels separated by small, often temporary, islands called braid bars or, in English usage, ''aits'' or ''eyots''. Braided streams tend to occur in rivers with high sediment l ...

s in New Zealand. The Rakaia River has a mean flow of and a mean annual seven-day low flow of . In the 1850s, European settlers named it the ''Cholmondeley River'', but this name lapsed into disuse.

Description

It rises in the

Southern Alps The Southern Alps (; officially Southern Alps / Kā Tiritiri o te Moana) is a mountain range extending along much of the length of New Zealand's South Island, reaching its greatest elevations near the range's western side. The name "Southern ...

, travelling in a generally easterly or southeasterly direction before entering the

Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the continen ...

south of

Christchurch Christchurch ( ; mi, Ōtautahi) is the largest city in the South Island of New Zealand and the seat of the Canterbury Region. Christchurch lies on the South Island's east coast, just north of Banks Peninsula on Pegasus Bay. The Avon River / ...

. It forms a

hapua A hapua is a river-mouth lagoon on a mixed sand and gravel (MSG) beach, formed at the river-coast interface where a typically braided, although sometimes meandering, river interacts with a coastal environment that is significantly affected by long ...

as it reaches the ocean. For much of its journey, the river is

braided Braided is a musical group consisting of Casey LeBlanc, Ashley Leitão, and Amber Fleury, who all competed on the third season of '' Canadian Idol'' in 2005. They are the third music group to come from an Idol show in the world, after Young Div ...

, running through a wide shingle bed. Close to

Mount Hutt Mount Hutt ( mi, Opuke) rises to the west of the Canterbury Plains in the South Island of New Zealand, above the braided upper reaches of the Rakaia River, and 80 kilometres west of Christchurch. Its summit is 2190 metres above sea level. The Ne ...

, however, it is briefly confined to a narrow canyon known as the

Rakaia Gorge The Rakaia Gorge is located on the Rakaia River in inland Canterbury in New Zealand's South Island. Like its neighbour, the Waimakariri River, the Rakaia runs through wide shingle beds for much of its length, but is forced through a narrow can ...

. The Rakaia River is bridged in two places. The busiest crossing is at the small town of

Rakaia Rakaia is a town seated close to the southern banks of the Rakaia River on the Canterbury Plains in New Zealand's South Island, approximately 57 km south of Christchurch on State Highway 1 and the Main South Line. Immediately north of the ...

, from the river mouth, where

State Highway 1 The following highways are numbered 1. For roads numbered A1, see list of A1 roads. For roads numbered B1, see list of B1 roads. For roads numbered M1, see List of M1 roads. For roads numbered N1, see list of N1 roads. For roads numbere ...

using

Rakaia Bridge The Rakaia Bridge is New Zealand's longest road bridge and crosses the Rakaia River, one of Canterbury, New Zealand, Canterbury's large braided rivers. The present bridge was opened in 1939 and replaced an earlier combined road and rail bridge f ...

and the

South Island Main Trunk Railway The Main North Line between Picton and Christchurch and the Main South Line between Lyttelton and Invercargill, running down the east coast of the South Island of New Zealand, are sometimes together referred to collectively as the South Isla ...

cross the river using separate bridges. These two bridges are New Zealand's longest road and rail bridges respectively, approximately long. A second bridge, much shorter and less used, spans the Rakaia Gorge. The

Central Plains Water Central Plains Water, or, more fully, the Central Plains Water Enhancement Scheme, is a large-scale proposal for water diversion, damming, reticulation and irrigation for the Central Plains of Canterbury, New Zealand. Construction started on the ...

Trust is proposing to take up to of water from the Rakaia River as part of the

enhancement scheme. The Rakaia River is a celebrated

Chinook salmon The Chinook salmon (''Oncorhynchus tshawytscha'') is the largest and most valuable species of Pacific salmon in North America, as well as the largest in the genus ''Oncorhynchus''. Its common name is derived from the Chinookan peoples. Other ve ...

fishery. It has been identified as an

Important Bird Area An Important Bird and Biodiversity Area (IBA) is an area identified using an internationally agreed set of criteria as being globally important for the conservation of bird populations. IBA was developed and sites are identified by BirdLife Int ...

BirdLife International BirdLife International is a global partnership of non-governmental organizations that strives to conserve birds and their habitats. BirdLife International's priorities include preventing extinction of bird species, identifying and safeguarding ...

because it supports breeding colonies of the

endangered An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching and inva ...

black-billed gull The black-billed gull (''Chroicocephalus bulleri''), Buller's gull, or tarāpuka (Māori) is a Near Threatened species of gull in the family Laridae. This gull is found only in New Zealand, its ancestors having arrived from Australia around 250, ...

. The river is also known for its large

wrybill The wrybill or (in Māori) ngutuparore (''Anarhynchus frontalis'') is a species of plover endemic to New Zealand. It is the only species of bird in the world with a beak that is bent sideways in one direction, always to the right (in the crossbil ...

population which represents 73 percent of the total population. Other important bird species using the riverbed are

black-fronted tern The black-fronted tern (''Chlidonias albostriatus''), also known as sea martin, ploughboy, inland tern, riverbed tern or tarapiroe,Rod Morris and Alison Ballance, ''"Rare Wildlife of New Zealand"'', Random House, 2008 is a small tern generally f ...

and

banded dotterel The double-banded plover (''Charadrius bicinctus''), known as the banded dotterel or pohowera in New Zealand, is a species of bird in the plover family. Two subspecies are recognised: the nominate ''Charadrius bicinctus bicinctus'', which breeds ...

.O’Donnell, C.F.J. (2000). The significance of river and open water habitats for indigenous birds in Canterbury, New Zealand, Environment Canterbury Unpublished Report U00/37.

References

External links

Selwyn District Council page for the Rakaia RiverTe Ara website page for the Rakaia RiverSalmon fishing on the Rakaia River
{{Rakaia Rivers of Canterbury, New Zealand Braided rivers in New Zealand Important Bird Areas of New Zealand Rivers of New Zealand