The Taramakau River is a river of the West Coast Region of the South Island of New Zealand.[1] It rises in the Southern Alps / Kā Tiritiri o te Moana near Harper Pass, 80 kilometres (50 mi) due east of Hokitika, and runs westward for 75 kilometres (47 mi) into the Tasman Sea 15 kilometres (9.3 mi) south of Greymouth.[1][2]

Taramakau River
View westwards from near Jacksons
Map
Route of the Taramakau River
Taramakau River is located in New Zealand
Taramakau River
Mouth of the Taramakau River
Taramakau River is located in South Island
Taramakau River
Taramakau River (South Island)
EtymologyFrom Kāi Tahu Māori: tere - to flow, and makau - curve or bend
Native nameTeremakau (Māori)
Location
CountryNew Zealand
RegionWest Coast Region
DistrictWestland District
Physical characteristics
SourceHarper Pass
 • locationSouthern Alps / Kā Tiritiri o te Moana
 • coordinates42°44′07″S 171°52′56″E / 42.735303°S 171.882091°E / -42.735303; 171.882091
 • elevation1,220 m (4,000 ft)
MouthKumara Junction
 • location
Tasman Sea
 • coordinates
42°33′56″S 171°07′30″E / 42.565614°S 171.125064°E / -42.565614; 171.125064
 • elevation
0 m (0 ft)
Length75 kilometres (47 mi)
Basin features
Tributaries 
 • leftOtehake River, Ōtira River, Taipo River, Big Wainihinihi River
 • rightMichael Creek, Taverners Creek, Rubieslaw Creek, Greenstone River / Hokonui

The Taramakau River forms the administrative boundary between the Westland District to the south and the Grey District to the north.[3][4]

Several small rivers are tributaries of the Taramakau. The largest of upper tributaries are the Otehake River and the Ōtira River. The valley of the Ōtira forms the western approach to Arthur's Pass.[5] The Taipo River is a major tributary joining the Taramakau from the south, downstream of Inchbonnie.[6]

Statutory acknowledgement edit

The South Island iwi Ngāi Tahu have manawhenua or tribal authority over the Taramakau River, acknowledged under s56 of the Ngāi Tahu Claims Settlement Act 1998.[7] The Taramakau was a traditional route of travel across the Southern Alps, providing access to Nōti Taramakau (Harper Pass), one of the lowest and most accessible passes through the mountainous terrain. The river has also been a source of the highly prized stone pounamu.[8]

Taramakau Bridge at Kumara Junction edit

 
The cable tram used for crossing the Taramakau River before a bridge was built

The Taramakau River posed significant difficulties and dangers for early travellers on the West Coast. The explorer Henry Whitcombe drowned crossing the river on 6 May 1863. There are two memorials to Whitcombe; one on the river's left bank at the (road-)rail bridge, and he is one of the four men commemorated by the Westland Explorers' Monument in Hokitika Cemetery.[9] Before a bridge was built near the coast, a cable way operated across the river, carrying a tram car.

 
Taramakau road-rail bridge opening (1893)

On 18 December 1893, the railway line from Hokitika to Greymouth opened, including a 220 metres (720 ft) long single-lane road and rail bridge across the Taramakau River near Kumara Junction.[10] By 2016, this bridge was New Zealand's last remaining road and rail bridge. There were 25 crashes on the bridge in the 10 years to June 2015, including one fatality in 2012.[11] The one-lane bridge also caused traffic congestion on State Highway 6, because vehicles had to queue before crossing. Work on a new road bridge commenced in 2016[11] and was completed at a cost of $25 million.[12] The new bridge was opened on 22 July 2018. The old bridge continued in service as a rail-only bridge.[13]

Stopbanks at Inchbonnie edit

The Taramakau River crosses the Alpine Fault at Inchbonnie. At this point, it has in its history flowed in three different directions: westwards along its present course, northwards towards and into Lake Brunner via the Ōrangipuku River, and northeast through Lake Poerua, the Poerua River and the lower reaches of Crooked River into Lake Brunner. Inchbonnie is located on an alluvial fan that infills the three valleys. If the Taramakau River changed course at Inchbonnie, in addition to the damage to arable farming land, it would cause increased flows in the Arnold and Grey Rivers. The effective design capacity of existing flood protection works at Greymouth would be reduced, increasing the flood risk exposure of the town.[14]

In the early 1900s, the Taramakau River overflowed into the Ōrangipuku River on several occasions, raising the risk of “breaking-through” to Lake Brunner. Investigations of river protection works began as early as 1907. In February 1946, floodwaters from the Taramakau again flowed into the Ōrangipuku River causing significant problems, and in October that year a proposal was developed to construct a stopbank along the north bank of the Taramakau River. In 1953 a small project involving 60 metres of tree protection and 80 metres of rockwork and was approved. However, by 1958, erosion had progressed to the point that there was only 5 metres of land remaining between the Taramakau and Ōrangipuku Rivers, and emergency works were required. A report prepared in March 1959 recommended construction of 2.5 kilometres (1.6 mi) of new stopbanks, strengthening and raising 1.2 kilometres (0.75 mi) of existing stopbanks, plus 2.5 kilometres (1.6 mi) of new rock rip rap, and diverting the upper section of the Ōrangipuku River into the Taramakau River. This proposal was only partially implemented to contain costs for ratepayers, with works including 900 metres (3,000 ft) of rock riprap, and strengthening and raising stopbanks where there was inadequate freeboard. In August 1959, a 3:1 subsidy was provided by the NZ Soil Conservation and River Control Council for a larger project involving placement of 17,300 tonnes of rock, 9,000 cubic metres of fill for stopbanks and 3,200 tonnes of rock for “topping-up”.[15]

The river protection works at Inchbonnie are some of the most critical flood defences managed by the West Coast Regional Council, because of the widespread consequences if they failed.[14]

References edit

  1. ^ a b Sheridan, Mattilda (2014). The effects of an Alpine Fault earthquake on the Taramakau River, South Island New Zealand (MSc). University of Canterbury. doi:10.26021/8885. Archived from the original on 10 November 2020. Retrieved 10 November 2020.
  2. ^ "Taramakau hunting". www.doc.govt.nz. Archived from the original on 10 November 2020. Retrieved 10 November 2020.
  3. ^ "About Westland District – Land". Westland District Council. Archived from the original on 19 June 2022. Retrieved 14 July 2022.
  4. ^ "About the Grey District – Grey District Council". Grey District Council. Archived from the original on 21 June 2022. Retrieved 14 July 2022.
  5. ^ "Taramakau River". nzfishing.com. Archived from the original on 10 November 2020. Retrieved 10 November 2020.
  6. ^ Haast, Julius von (1879). "Geology of the Provinces of Canterbury and Westland, New Zealand : a report comprising the results of official explorations - The Taramakau". New Zealand Electronic Text Collection. Retrieved 16 July 2022 – via Victoria University of Wellington.
  7. ^ "Ngai Tahu Claims Settlement Act 1998 No 97". New Zealand Legislation. Retrieved 14 July 2022.
  8. ^ "Whenua – Taramakau". Te Karaka (79). Te Rūnanga o Ngāi Tahu. 3 October 2018. Archived from the original on 5 March 2021. Retrieved 14 July 2022.
  9. ^ Fields, Ron (1989). Hokitika: Place of Return. Craig Printing Company. p. 43. ISBN 0473007789.
  10. ^ Leitch & Scott 1995, p. 60.
  11. ^ a b Carroll, Joanne (14 December 2016). "Work to replace New Zealand's last rail-road bridge underway". Stuff. Retrieved 15 July 2022.
  12. ^ "West Coast 2019 update". Waka Kotahi NZ Transport Agency. August 2019. Retrieved 20 August 2022.
  13. ^ "SH6 New Taramakau Bridge Project | Waka Kotahi NZ Transport Agency". www.nzta.govt.nz. Retrieved 15 July 2022.
  14. ^ a b "West Coast Lifelines – Vulnerability and Interdependency Assessment – Supplement 9: Regional Flood Control Assets" (PDF). West Coast Civil Defence Emergency Management Group. August 2017. Archived (PDF) from the original on 27 January 2022. Retrieved 14 July 2022.
  15. ^ "Inchbonnie Rating District – 2021–2024 Asset Management Plan" (PDF). West Coast Regional Council. Archived (PDF) from the original on 15 July 2022. Retrieved 14 July 2022.

Bibliography edit

  • Leitch, David; Scott, Brian (1995). Exploring New Zealand's Ghost Railways (1998 ed.). Wellington: Grantham House. ISBN 1-86934-048-5.

External links edit