Tangahoe River#Tunnel
{{Short description|River in New Zealand}}
{{Use New Zealand English|date=April 2023}}
{{Infobox river
| name =Tangahoe River
| image =Tangahoe River estuary.jpg
| image_size =
| image_caption = 1865 painting of soldiers crossing the river at the beach during the Second Taranaki War
| source1_location =
| mouth_location =South Taranaki Bight
| subdivision_type1 = Country
| subdivision_name1 =New Zealand
| length ={{convert|27|km|mi|abbr=on}}
| source1_elevation ={{convert|256|m|ft|abbr=on}}
| mouth_elevation =
| discharge1_avg ={{Convert|4.2|m3/s|ft3/s|abbr=on}}
| basin_size ={{convert|297.6|km2|mi2|abbr=on}}
}}The Tangahoe River is a river of the Taranaki Region of New Zealand's North Island. It flows generally southwest from its origins in hill country to the east of Lake Rotorangi, reaching the Tasman Sea in the South Taranaki Bight {{Convert|5|km|mi|abbr=on}} southeast of Hāwera.
Name
An elder, of Tangahoe and Ngāti Hine descent, said the origin of the name, Tangahoe, is that it was given to the river following the loss of a steering oar (hoe) from a fishing waka (boat) at sea, trying to return to its tauranga waka (landing place). It was said that, had it had two steering oars, as on the Aotea waka, then it would have reached its landing.
Pre colonial value
The Ngāti Ruanui Claims Settlement Act 2003 said the river was a major source of resources, providing shellfish and fish, including piharau, kōkopu, tuna and pātiki,{{Cite web|url=https://trc.govt.nz/assets/Documents/Plans-policies/SoilWaterPlanReview/DraftFLMP-Outstanding-WB-Jan2016.pdf|title=Freshwater bodies of outstanding or significant value in the Taranaki region|last=|first=|date=2016|website=Taranaki Regional Council|access-date=}} birds such as kererū, pūkeko, tiwaiwaka, kāhu, kākāpō, kiwi, korimako, miromiro and pīpīwharauroa and plants, including koromiko, kōhia, hinau, piripiri, mamaku, and rewarewa.{{Cite web|url=http://www.legislation.govt.nz/act/public/2003/0020/7.0/DLM193662.html|title=Ngati Ruanui Claims Settlement Act 2003 No 20 (as at 23 May 2008), Public Act Schedule 7 Statutory acknowledgement for Tangahoe River – New Zealand Legislation|website=www.legislation.govt.nz|language=en-NZ|access-date=2017-03-08}}
Defensive sites
File:Otapawa_pa,_south_taranaki.jpg
The steep valley sides of the lower river provided good defensive sites, as marked on the [http://www.topomap.co.nz/NZTopoMap/nz45066/Ohangai-Pa/Taranaki 1:50,000 map].
Otapawa pā was held by Tangahoe, Pakakohi and Ngāti Ruanui when it was attacked on 16 January 1866, during the Second Taranaki War. The account of the attack in '
Te Ruaki Pa has also been damaged - by cattle.{{Cite news|url=http://www.newshub.co.nz/home/syspages/--headline--.html|archive-url=https://web.archive.org/web/20161215121757/http://www.newshub.co.nz/home/syspages/--headline--.html|url-status=dead|archive-date=December 15, 2016|title=Cows desecrate historical pa|date=1970-01-01|newspaper=Newshub|access-date=2017-03-07}}
Tangahoe and Inman's Redoubts date from 17 March 1865. They remain in good condition under pasture.
Geology
The river rises on a sandy mid-Pliocene Tangahoe Mudstone, formed in a shallow sea,{{Cite journal|title=An integrated sequence stratigraphic, palaeoenvironmental, and chronostratigraphic analysis of the Tangahoe Formation, southern Taranaki coast, with implications for mid-Pliocene (c. 3.4-3.0 Ma) glacio-eustatic sea-level changes|journal=Journal of the Royal Society of New Zealand|volume=35|issue=1–2|pages=151–196|doi=10.1080/03014223.2005.9517780|year = 2005|last1 = Naish|first1 = Tim R.|last2=Wehland|first2=Florian|last3=Wilson|first3=Gary S.|last4=Browne|first4=Greg H.|last5=Cook|first5=Richard A.|last6=Morgans|first6=Hugh E. G.|last7=Rosenberg|first7=Michael|last8=King|first8=Peter R.|last9=Smale|first9=David|last10=Nelson|first10=Campbell S.|last11=Kamp|first11=Peter J. J.|last12=Ricketts|first12=Brian|hdl=10289/3485|hdl-access=free}} then its valley is cut down to early-Pliocene Whenuakura Group rocks (bioclastic limestone, pebbly and micaceous sandstones and massive siltstone), whilst the surrounding land is covered by mid-Pleistocene beach deposits of conglomerate, sand, peat and clay.{{Cite web|url=http://www.gns.cri.nz/static/qmapdata/newmaps/QTaranaki.zip|title=1:250,000 geological map Taranaki|last=|first=|date=|website=|access-date=}} The river carries about 43,900 tonnes of sediment to the sea each year.{{Cite web|url=http://www.epa.govt.nz/Publications/TTR_Impact_Assessment_Final_Part_II_Chapters_6-9.pdf|title=Impact Assessment South Taranaki Bight Iron Sand Extraction Project Trans-Tasman Resources Limited Marine Consent Application|last=|first=|date=October 2013|website=Environmental Protection Authority|access-date=}} It enters the sea between 30 and 50 m tall cliffs, eroded over the last 15,000 years, following tectonic uplift. Of the rivers flowing into the S Taranaki Bight, the Tangahoe ranks 13th for flow but 9th for sediment input, with a sediment rate of 1.39 kg/s.{{Cite web|url=http://www.epa.govt.nz/EEZ/EEZ000011/NIWA_Sediment_Plume_Modelling_Report_Full_version.pdf|title=NIWA Sediment Plume Modelling Report|last=|first=|date=October 2015|website=Environmental Protection Authority|access-date=}}
Water quality
Water quality in Taranaki has been under pressure. Quality varies over the length of the river, as shown in the table -
In the summer of 2016 the MCI level at the viaduct was the lowest ever, probably due to earthworks by Fonterra, causing the rating to drop to poor.{{Cite web|url=https://www.trc.govt.nz/assets/Documents/Environment/Monitoring-SOE/Freshwater-MCI/SEM-MCI16-w.pdf|title=Freshwater Macroinvertebrate Fauna Biological Monitoring Programme Annual State of the Environment Monitoring Report 2015-2016|last=|first=|date=2017|website=Taranaki Regional Council|access-date=}} Tangahoe is listed 5th in Taranaki for modification, with {{Convert|2.27|km|mi|abbr=on}} of consented stream modification in its catchment.{{Cite web|url=https://trc.govt.nz/assets/Documents/Research-reviews/Freshwater/SmallStreams2010.pdf|title=Small Stream Modification in Taranaki|last=|first=|date=2010|website=Taranaki Regional Council|access-date=}} Fonterra's Whareroa dairy has a consent to draw {{Convert|30,000,000|l|impgal|abbr=on}} of water a day from the Tangahoe's tributary, the Tawhiti Stream,{{Cite news|url=http://www.farmersjournal.ie/fonterra-on-track-to-complete-25m-investment-215515|title=Fonterra on track to complete €25m investment|access-date=2017-03-07|language=en}} where flows, temperature, etc. are recorded at both Tawhiti Rd{{Cite web|url=https://www.trc.govt.nz/environment/maps-and-data/site-details/?siteID=35&measureID=9|title=Taranaki Regional Council – Site Details|website=www.trc.govt.nz|language=en-NZ|access-date=2017-03-07}} and Whareroa.{{Cite web|url=https://www.trc.govt.nz/environment/maps-and-data/site-details/?siteID=34&measureID=1|title=Taranaki Regional Council – Site Details|website=www.trc.govt.nz|language=en-NZ|access-date=2017-03-07}} {{Convert|1,741,050|l|impgal|abbr=on}} is also consented for irrigation.{{Cite web|url=https://www.lawa.org.nz/explore-data/taranaki-region/water-quantity/surface-water-zones/tangahoe/|title=Land, Air, Water Aotearoa (LAWA) - Tangahoe|last=|first=|date=|website=www.lawa.org.nz|access-date=2017-03-07}} The dairy removes silt from the water with plastic microbeads.{{Cite web|url=http://www.stuff.co.nz/taranaki-daily-news/news/82322375/millions-of-plastic-beads-dumped-illegally-in-south-taranaki|title=Millions of plastic beads dumped illegally in South Taranaki|website=Stuff|access-date=2017-03-23}}
Tunnel
File:Tangahoe_Valley_Road_tunnel,_Taranaki,_New_Zealand.jpg
Tangahoe Valley Tunnel runs under the ridge separating Pukekino Rd (leading to Lake Rotorangi) from the Tangahoe Valley.{{Cite web|url=http://www.topomap.co.nz/NZTopoMap/nz45449/Tanahoe-Lodge/Taranaki|title=Tanahoe Lodge, Taranaki - NZ Topo Map|website=NZ Topo Map|language=en|access-date=2017-03-05}} The {{Convert|160|m|ft|abbr=on}} tunnel was built in 1928.{{Cite web|url=http://ketenewplymouth.peoplesnetworknz.info/taranaki_tunnels/topics/show/1138-tangahoe-tunnel-tangahoe-valley-road-hawera|title=Tangahoe Tunnel - Tangahoe Valley Road, Hawera|last=|first=|date=|website=ketenewplymouth.peoplesnetworknz.info|language=en|access-date=2017-03-05}} Digging was from both ends and didn't quite meet in the middle, hence a variation in the roof height in the centre.{{Cite web|url=http://pukeariki.com/Learning-Research/Taranaki-Research-Centre/Taranaki-Stories/Taranaki-Story/id/670/title/road-tunnels-of-taranaki|title=Taranaki Story - Road Tunnels of Taranaki|last=|first=|date=|website=pukeariki.com Puke Ariki Museum Libraries Tourist Information Taranaki|language=en-NZ|access-date=2017-03-05}}
In 1954 shotcrete was sprayed to consolidate the walls.
In 1986 part of the roof collapsed in an earthquake and the tunnel was closed. A deep and unstable cutting alongside, which proved to be often unpassable, served for traffic until, in 1996, South Taranaki District Council decided to reopen the tunnel, which re-opened in 1997, at a cost of $245,000.{{Cite web|url=https://www.southtaranaki.com/uploaded_files/Meetings/Council/Asset%20Management%20Plan%20-%20Roading%20-%202013-2014.pdf|title=Asset Management Plan – Roading 2013-2014|last=|first=|date=|website=South Taranaki District Council|access-date=}}
In 2003 further restoration work was required, costing $250,000 to remove {{Convert|25,000|m3|yd3|abbr=on}} in the tunnel approaches, a further {{Convert|10,000|m3|yd3|abbr=on}} to reach the portal and add {{Convert|1000|m|yd|abbr=on}} of rock bolts. Further repairs were done in 2009.
Bridges
Tangahoe Valley Rd crosses the river on a {{Convert|24.2|m|ft|abbr=on}} through arch bridge which replaced one destroyed by floods in 1937, the new bridge being {{Convert|2.4|m|ft|abbr=on}} above the highest recorded flood level.{{Cite web|url=http://ketenewplymouth.peoplesnetworknz.info/heritage_sites_and_features/topics/show/2491-tangahoe-river-bridge-1937|title=Tangahoe River Bridge - 1937|last=|first=|date=|website=ketenewplymouth.peoplesnetworknz.info|language=en|access-date=2017-03-05}} The road was surveyed in 1898,{{Cite web|url=https://paperspast.natlib.govt.nz/newspapers/HNS18980429.2.4|title=News and Notes. (Hawera & Normanby Star, 1898-04-29)|last=|first=|date=|website=paperspast.natlib.govt.nz National Library of New Zealand|language=en|access-date=2017-03-07}} money had been spent by 1900{{Cite web|url=https://paperspast.natlib.govt.nz/newspapers/HNS19000906.2.9|title=TANGAHOE VALLEY ROAD. (Hawera & Normanby Star, 1900-09-06)|last=|first=|date=|website=paperspast.natlib.govt.nz National Library of New Zealand|language=en|access-date=2017-03-07}} and the road needed repair after floods in 1903,{{Cite web|url=https://paperspast.natlib.govt.nz/newspapers/HNS19030605.2.8|title=NEWS AND NOTES. (Hawera & Normanby Star, 1903-06-05)|last=|first=|date=|website=paperspast.natlib.govt.nz National Library of New Zealand|language=en|access-date=2017-03-07}} when £500 was voted for a bridge.{{Cite web|url=https://paperspast.natlib.govt.nz/newspapers/TDN19031120.2.10|title=Public Works Estimates. (Taranaki Daily News, 1903-11-20)|last=|first=|date=|website=paperspast.natlib.govt.nz National Library of New Zealand|language=en|access-date=2017-03-07}} A bridge was built in 1920{{Cite web|url=https://paperspast.natlib.govt.nz/newspapers/TDN19200308.2.12|title=HAWERA COUNTY COUNCIL. (Taranaki Daily News, 1920-03-08)|last=|first=|date=|website=paperspast.natlib.govt.nz National Library of New Zealand|language=en|access-date=2017-03-07}} and the road gradually extended up the valley, with money still being voted in 1924.{{Cite web|url=https://paperspast.natlib.govt.nz/newspapers/HNS19241029.2.59|title=ROADS AND BRIDGES. (Hawera & Normanby Star, 1924-10-29)|last=|first=|date=|website=paperspast.natlib.govt.nz National Library of New Zealand|language=en|access-date=2017-03-07}}
Ohangai Rd crosses the river on a single lane bridge.{{Cite web|url=http://www.stuff.co.nz/taranaki-daily-news/news/south-taranaki-star/83011666/flashing-signs-plan-for-oneway-bridges|title=Flashing signs plan for one-way bridges|website=Stuff|access-date=2017-03-06}} The road was mentioned in 1877{{Cite web|url=https://paperspast.natlib.govt.nz/newspapers/PATM18770613.2.12|title=HAWERA ROAD BOARD. (Patea Mail, 1877-06-13)|last=|first=|date=|website=paperspast.natlib.govt.nz National Library of New Zealand|language=en|access-date=2017-03-06}} and the bridge was old enough to need repairs by 1919.{{Cite web|url=https://paperspast.natlib.govt.nz/newspapers/HNS19190705.2.59|title=HAWERA COUNTY COUNCIL. (Hawera & Normanby Star, 1919-07-05)|last=|first=|date=|website=paperspast.natlib.govt.nz National Library of New Zealand|language=en|access-date=2017-03-06}} A new bridge was built in 1920.{{Cite web|url=https://paperspast.natlib.govt.nz/newspapers/TDN19200810.2.5|title=HAWERA COUNTY COUNCIL. (Taranaki Daily News, 1920-08-10)|last=|first=|date=|website=paperspast.natlib.govt.nz National Library of New Zealand|language=en|access-date=2017-03-07}}{{Cite web|url=https://paperspast.natlib.govt.nz/newspapers/TDN19201012.2.4|title=HAWERA COUNTY COUNCIL. (Taranaki Daily News, 1920-10-12)|last=|first=|date=|website=paperspast.natlib.govt.nz National Library of New Zealand|language=en|access-date=2017-03-07}}
File:Tangahoe_River_bridge.jpg
State Highway 3 crosses the river on a {{Convert|65.5|m|ft|abbr=on}} bridge.{{Cite web|url=http://his.aucklandmotorways.net/PDFs//TARANAKI/20_606_TARANAKI_WEST%20WANGANUI_003_20.pdf|title=Highway Information sheet 003-0310|last=|first=|date=|website=|access-date=}} Until 1871 the route was via Manawapou Rd and the beach at low tide.{{Cite web|url=https://paperspast.natlib.govt.nz/newspapers/EP18710711.2.8|title=OVERLAND FROM TARANAKI TO WELLINGTON. (Evening Post, 1871-07-11)|last=|first=|date=|website=paperspast.natlib.govt.nz National Library of New Zealand|language=en|access-date=2017-03-06}} A bridge was built in 1871{{Cite web|url=https://paperspast.natlib.govt.nz/newspapers/TH18710902.2.25|title=MONTHLY SUMMARY. (Taranaki Herald, 1871-09-02)|last=|first=|date=|website=paperspast.natlib.govt.nz National Library of New Zealand|language=en|access-date=2017-03-06}} and replaced in 1887.{{Cite web|url=https://paperspast.natlib.govt.nz/newspapers/HNS18871003.2.11|title=NEWS AND NOTES. (Hawera & Normanby Star, 1887-10-03)|last=|first=|date=|website=paperspast.natlib.govt.nz National Library of New Zealand|language=en|access-date=2017-03-06}} In 1935 it was swept away by a flood on 22 February 1935 and temporarily replaced.{{Cite web|url=https://paperspast.natlib.govt.nz/newspapers/EP19350523.2.94.13|title=FEARS AT HAWERA (Evening Post, 1935-05-23)|last=|first=|date=|website=paperspast.natlib.govt.nz National Library of New Zealand|language=en|access-date=2017-03-06}} Relief work to replace it and its winding route{{Cite news|url=https://www.wams.org.nz/wams_desktop/index.html?scale=18055.954822¢er=1716001.1863,5612464.4997|title=Walking Access Mapping System|last=Stella|access-date=2017-03-06}} had already started in 1933{{Cite web|url=https://paperspast.natlib.govt.nz/newspapers/EP19331023.2.51|title=NEWS OF THE DAY (Evening Post, 1933-10-23)|last=|first=|date=|website=paperspast.natlib.govt.nz National Library of New Zealand|language=en|access-date=2017-03-07}} and was completed in 1936 at a cost of £6,000.{{Cite web|url=https://paperspast.natlib.govt.nz/newspapers/NZH19360611.2.156|title=NEW BRIDGE BUILT (New Zealand Herald, 1936-06-11)|last=|first=|date=|website=paperspast.natlib.govt.nz National Library of New Zealand|language=en|access-date=2017-03-07}} It was widened from {{Convert|6|m|ft|abbr=on}} to {{Convert|7.5|m|ft|abbr=on}} in 2008.{{Cite news|url=http://www.stuff.co.nz/taranaki-daily-news/359040/Narrow-Tangahoe-Bridge-no-more|title=Narrow Tangahoe Bridge no more|work=Stuff|access-date=2017-03-05}} There were 7 crashes in the 4 years prior to widening.{{Cite web|url=https://www.nzta.govt.nz/assets/resources/road-safety-data-regions/taranaki/docs/2010.pdf|title=Taranaki Region Road Safety Report 2005 - 2009 Table 9.3|last=|first=|date=|website=NZTA|access-date=}}
The New Plymouth railway crosses the river about a kilometre downstream from SH3, on a 9-span trestle bridge {{Convert|220|ft|m|abbr=on|order=flip}} long, the centre span being {{Convert|60|ft|m|abbr=on|order=flip}}, and the 4 each side of {{Convert|10|ft|m|abbr=on|order=flip}} to {{Convert|40|ft|m|abbr=on|order=flip}}. The smaller spans are on piles driven into the rock, but the centre piers are concrete {{Convert|18|ft|m|abbr=on|order=flip}} deep. The bridge was of totara {{Convert|80|ft|m|abbr=on|order=flip}} above the river, or {{Convert|65|ft|m|abbr=on|order=flip}} above flood level.{{Cite web|url=https://paperspast.natlib.govt.nz/newspapers/HNS18840426.2.9.3|title=THE RAILWAY WORKS. (Hawera & Normanby Star, 1884-04-26)|last=|first=|date=|website=paperspast.natlib.govt.nz National Library of New Zealand|language=en|access-date=2017-03-06}} A tender was accepted for a rebuild in 1910.{{Cite web|url=https://paperspast.natlib.govt.nz/newspapers/NZTIM19100101.2.24|title=CURRENT TOPICS (New Zealand Times, 1910-01-01)|last=|first=|date=|website=paperspast.natlib.govt.nz National Library of New Zealand|language=en|access-date=2017-03-07}}
See also
- List of rivers of New Zealand
- Lake Rotokare on the Te Ararata Stream tributary
References
{{LINZ|id=|name=Tangahoe River|accessdate=12 July 2009}}{{Reflist}}{{coord|39|39|S|174|21|E|region:NZ_type:river_source:GNS-enwiki|display=title}}
External links
- [https://s3.amazonaws.com/gs-geo-images/39c2638e-3cc1-4d27-9fa9-21f178e8dc8a_l.jpg 1895 plans of Tangahoe Valley Rd bridge]
- [https://s3.amazonaws.com/gs-geo-images/d058d1b7-8463-41a7-8a2b-1589957dd58f_l.jpg 2011 plans for bridge strengthening]
- photos - [https://paperspast.natlib.govt.nz/newspapers/EP19360619.2.50.5 1936 bridge], [http://www.aucklandcity.govt.nz/dbtw-wpd/exec/dbtwpub.dll?BU=http%3A%2F%2Fwww.aucklandcity.govt.nz%2Fdbtw-wpd%2FHeritageImages%2Findex.htm&AC=QBE_QUERY&TN=heritageimages&QF0=ID&NP=2&MR=5&RF=HIORecordSearch&QI0=%3D%22AWNS-19360108-51-3%22 bridge scaffolding], [http://ketenewplymouth.peoplesnetworknz.info/taranaki_tunnels/images/show/7172-tangahoe-tunnel-east-portal tunnel eastern portal], [https://www.lawa.org.nz/media/2632437/tangahoe-ds-railbridge.jpg river at the rail bridge],
{{South Taranaki District}}