Perth River
{{Short description|River in New Zealand}}
{{Use New Zealand English|date=April 2024}}
{{Use dmy dates|date=July 2019}}
{{Infobox river
| name = Perth River
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| image = Perth River Upper Reaches Westland New Zealand.jpg
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| image_caption = Upper Reaches of the Perth River
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| subdivision_type1 = District
| subdivision_name1 = Westland District
| subdivision_type2 = Region
| subdivision_name2 = West Coast Region
| subdivision_type3 = Country
| subdivision_name3 = New Zealand
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| source1 = Perth Glacier
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| mouth_location = Whataroa River
| mouth_coordinates = {{coord|43|20|S|170|27|E|display=inline,title|region:NZ_type:river_source:GNS-enwiki}}
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| tributaries_left = Barlow River
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The Perth River is a river in the Southern Alps in the West Coast region of New Zealand's South Island. Its source is in terrace icefields north of the Rangitata Divide and is joined by multiple tributaries, including a creek from Abel Lake. It features a number of rapids and passes through two gorges before meeting the Whataroa River. The river is largely inaccessible, but recently, an adventure tourism company has begun offering "heli-rafting" on the river: whitewater rafters are flown in by helicopter to raft the river.
Recreation
Kayakers have been flying ("heli-boating") up the Perth for a number of years. The normal rafting put-in at Five-Finger stream gives a nice class III-IV run with one amazing gorge. By flying up to Scone Hut, the trip becomes one of the best IV-V runs on the coast. More recently paddlers have been flying or walking upstream of scone hut for some V-V+ excitement.{{citation needed|date=February 2021}}
The Perth River valley track is an advanced tramping route along the valley. The full out and back route takes three or more days and provides access to a large area of Department of Conservation land. The route has two backcountry huts, Nolans Hut and Scone Hut.{{cite web |title=Whataroa, Butler and Perth valleys tracks |url= https://www.doc.govt.nz/parks-and-recreation/places-to-go/west-coast/places/whataroa-area/things-to-do/tracks/whataroa-butler-and-perth-valleys-tracks |access-date=22 February 2021 |publisher=Department of Conservation}}
Conservation
Zero Invasive Predators Ltd (ZIP) established a pest control programme in the Perth River Valley in 2015. The Perth, Barlow Rivers, and Southern Alps bound the {{Convert|12000|ha|acre}} area. In order to detect and eliminate all incursions, ZIP placed 368 trail cameras and 17 ZIP cameras in the Perth Barlow block. As surrounding blocks were removed of predators, this number went down. In 2022, there were only 91 cameras in the camera network.{{Cite web |date=2024-12-18 |title=ZIP Technical Report No. 13 - PFSW Impact Report by Zero Invasive Predators |url=https://issuu.com/zipnz/docs/zip_technical_report_no._13_-_pfsw_impact_report_f |access-date=2025-04-13 |website=Issuu |language=en}} The programme has effectively eradicated all pests in the valley, and its techniques and findings will be important in further conservation efforts across New Zealand.{{cite web| url=https://www.rnz.co.nz/national/programmes/ninetonoon/audio/2018731972/high-tech-predator-control-scheme-a-first |title=High tech predator control scheme a first |work=Radio New Zealand |date=30 January 2020 |access-date=22 February 2021}}