{{Short description|River in the South Island of New Zealand}} {{Use New Zealand English|date=April 2024}} {{Use dmy dates|date=July 2019}}

{{Infobox river|name=Ahaura River|image=Ahaura River Bridge.jpg|image_size=|image_caption=Ahaura River Bridge|source1_location=Tūtaekurī River and Waiheke River|mouth_location=Ahaura River|subdivision_type1=Country|subdivision_name1=New Zealand|length_km=65 |source1_elevation={{convert|270|m|abbr=on}}|mouth_elevation={{convert|40|m|abbr=on}}|discharge1_avg=|basin_size=}}

The '''Ahaura River''' is in the South Island of New Zealand. This river drains the western flanks of the Southern Alps and flows into the Grey River.

The Ahaura and its many tributaries rise in the Lake Sumner State Forest park and enters the Grey River at the small settlement of Ahaura approximately 30&nbsp;km upstream from Greymouth. It drains a huge area of land and in its lower reaches below the Haupiri confluence can have a tea-colour stain for much of the year. The reaches above the junction with the Haupiri tend to have very clear water however for much of the year.<ref>{{Cite web|url=https://www.nzfishing.com/FishingWaters/West%20Coast/WCFishingWaters/WCAhaura.htm|title=Ahaura River fishing-Ahaura River trout fishing-nzfishing|website=www.nzfishing.com|access-date=2018-07-17}}</ref>

Other rivers in the catchment are the Nancy, Trent, Tūtaekurī and Waiheke Rivers. They can all be kayaked, except in late summer and they are the most used rivers on the West Coast. The lower gorge has remnants of Chinese miners' gold diggings. Pack-tracks to Canterbury used to go through Amuri Pass into the Doubtful River Valley and by the Tūtaekurī to the Hope River. The Ahaura in the gorge is a wide, fast, shallow, braided river, with extensive grassy flats, surrounded by beech forest. Earthquake Rapid, is the largest rapid on the river. A 1981 survey described the scenic and recreational values of the gorge as exceptional.<ref name=":1">{{Cite web |last=G. D. and J. H. Egarr |date=1981 |title=Recreational River Survey |url=https://docs.niwa.co.nz/library/public/w&smp15.pdf |website=NIWA |issn=0110-4705}}</ref>

The river is only bridged by the Stillwater–Ngākawau Line and SH7.<ref>{{Cite web |title=Ahaura, West Coast |url=https://www.topomap.co.nz/NZTopoMap/nz34715/Ahaura/ |access-date=2023-01-02 |website=NZ Topo Map |language=en}}</ref> A punt operated across the river from 1871<ref>{{Cite web |date=7 Dec 1871 |title=GREY VALLEY DIGGINGS. GREY RIVER ARGUS |url=https://paperspast.natlib.govt.nz/newspapers/GRA18711207.2.10 |access-date=2023-01-02 |website=paperspast.natlib.govt.nz}}</ref> to 1879, when it was replaced by a bridge.<ref>{{Cite web |date=12 Apr 1879 |title=Grey River Argus |url=https://paperspast.natlib.govt.nz/newspapers/GRA18790412.2.4 |access-date=2023-01-02 |website=paperspast.natlib.govt.nz}}</ref> The first railway bridge opened in 1890.<ref>{{Cite web |date=11 Sep 1890 |title=THE OPENING OF AHAURA BRIDGE. Grey River Argus |url=https://paperspast.natlib.govt.nz/newspapers/GRA18900911.2.14 |access-date=2022-09-15 |website=paperspast.natlib.govt.nz}}</ref>

At the gorge the Ahaura's 7-day mean annual low flow is {{Convert|26.45|m3|abbr=on}} per second, the mean flow {{Convert|99.77|m3|abbr=on}} and the maximum recorded flow {{Convert|3,972.06|m3|abbr=on}}.<ref>{{Cite web |title=State of the Environment Summary 2018 |url=https://www.wcrc.govt.nz/repository/libraries/id:2459ikxj617q9ser65rr/hierarchy/Documents/Environment/State%20of%20Environment/SOEDocument_v12.pdf |website=West Coast Regional Council}}</ref> On 26 December 1957 the flood gauge at the SH7 bridge reached {{Convert|7.35|m|abbr=on}}. The river's catchment is {{Convert|870|km2|abbr=on}}.<ref>{{Cite web |title=West Coast and Canterbury Flooding ( 1957-12-26 ) |url=https://hwe.niwa.co.nz/event/December_1957_West_Coast_and_Canterbury_Flooding |access-date=2023-01-02 |website=hwe.niwa.co.nz}}</ref>

Gold digging started about 1865<ref>{{Cite web |date=1 Dec 1865 |title=THE WEST COAST GOLD-FIELDS. COLONIST |url=https://paperspast.natlib.govt.nz/newspapers/TC18651201.2.15 |access-date=2023-01-02 |website=paperspast.natlib.govt.nz}}</ref> and a small settlement of shanties had been built at Ahauru by January 1866.<ref>{{Cite web |date=20 January 1866 |title=The Grey. Nelson Examiner and New Zealand Chronicle |url=https://paperspast.natlib.govt.nz/newspapers/NENZC18660120.2.11 |access-date=2023-01-02 |website=paperspast.natlib.govt.nz}}</ref> 3,300 were reported to be at work in the area by March 1866<ref>{{Cite web |date=17 Mar 1866 |title=Nelson Evening Mail |url=https://paperspast.natlib.govt.nz/newspapers/NEM18660317.2.5 |access-date=2023-01-02 |website=paperspast.natlib.govt.nz}}</ref> and a bridle path had been formed.<ref>{{Cite web |date=10 Apr 1866 |title=Council Papers. NELSON EXAMINER AND NEW ZEALAND CHRONICLE |url=https://paperspast.natlib.govt.nz/newspapers/NENZC18660410.2.10 |access-date=2023-01-02 |website=paperspast.natlib.govt.nz}}</ref>

The Ahaura Terraces and Nancys Clearing Ecological Areas were declared in 1997 to protect kahikatea and red beech ({{lang|mi|tawhai raunui}}) forests on the river's terraces, including kākāriki parakeets.<ref>{{Cite web |date=1997 |title=Declaring Land to be Held as Ecological Areas West Coast |url=https://gazette.govt.nz/notice/id/1997-ln2301 |access-date=2023-01-02 |website=gazette.govt.nz}}</ref>

== See also == *List of rivers of New Zealand

== References == {{Reflist}}

{{coord|42|21|S|171|31|E|display=title|region:NZ_type:river_source:GNS-enwiki}} {{Grey River}} {{Grey District}}

Category:Grey District Category:Rivers of the West Coast Region Category:Rivers of New Zealand

{{WestCoastNZ-river-stub}}