{{Short description|River gorge in New Zealand}} {{Use New Zealand English|date=April 2024}} {{Use dmy dates|date=July 2019}}
{{Infobox valley | name = Cromwell Gorge | other_name =(Formerly: Dunstan Gorge) | translation = | photo = Miners Rockfall Cromwell Gorge.jpg | photo_size = 300px | photo_caption = Miners Rockfall overlooks Lake Dunstan at the northern entrance of the Cromwell Gorge | map = New Zealand | map_image = | map_caption = <!-- Location --> | location = | country = New Zealand | region = [[South Island, New Zealand|South Island]] | state = | district = [[Central Otago]] | city = | relief = 1 | label = | label_position = | coordinates = {{coord|-45.104|169.292}} | coordinates_ref = <!-- Statistics --> | elevation = | elevation_m = 194 | elevation_ft = | elevation_ref = | length = | length_mi = | length_km = 18.5 | length_orientation = | length_note = Cromwell to Clyde Dam | width = | width_mi = | width_km = 9 | width_orientation = | width_note = Cairnmuir Hill to Leaning Rock | area = | area_mi2 = | area_km2 = 84 | depth = | depth_ft = | depth_m = 1453 | type = | age = | border = | topo = NZMS260 G42 Edition 1 1990 | traversed = | river = [[Clutha River|Clutha River / Mata-Au]] <!-- Below --> | footnotes =Depth taken from Leaning Rock (1647 m) to Lake Dunstan (194 m) | embed = }}
The '''Cromwell Gorge''' is a steep gorge cut by the former [[Clutha River]] ([[Māori language|Māori]]: ''Mata-Au'') in the [[Central Otago]] region of New Zealand's [[South Island]].<ref>{{Cite web|date=2021-05-13|title=Roxburgh Gorge and Clutha Gold Trails: Going with the flow on the Clutha Mata-au|url=https://www.stuff.co.nz/travel/experiences/cycling-holidays/125130144/roxburgh-gorge-and-clutha-gold-trails-going-with-the-flow-on-the-clutha-mataau|access-date=2021-05-31|website=[[Stuff (website)|Stuff]] |language=en}}</ref> It winds {{Convert|19|km|mi|abbr=on}} between the [[Dunstan Mountains|Dunstan]] and Cairnmuir Mountains, linking the townships of [[Cromwell, New Zealand|Cromwell]] and [[Clyde, New Zealand|Clyde]]. It is one of three substantial river gorges in [[Central Otago]], the others being the [[Kawarau Gorge]] to the west of Cromwell, and the [[Roxburgh Gorge]] south of [[Alexandra, New Zealand|Alexandra.]]
Long-associated with gold mining, orchards and the production of [[stone fruit]], the gorge (including part of old Cromwell) was flooded in the early 1990s to form [[Lake Dunstan]] behind the [[hydroelectricity|hydroelectric]] [[Clyde Dam]].<ref>{{Cite web|date=19 November 2020|title=Back to the future|url=https://farmersweekly.co.nz/section/horticulture/view/back-to-the-future-4|url-status=live|access-date=2021-05-31|website=farmersweekly.co.nz|archive-url=https://web.archive.org/web/20201119044529/https://farmersweekly.co.nz/section/horticulture/view/back-to-the-future-4 |archive-date=19 November 2020 }}</ref> The former [[Otago Central Railway]] which traced the river through the gorge from Clyde was removed, while [[New Zealand State Highway 8|State Highway 8]] was realigned above the newly formed lake.<ref>{{Cite web|date=August 2018|title=Review of existing conservation plans for the Clyde Museums Feasibility Study Project|url=https://www.codc.govt.nz/repository/libraries/id:2apsqkk8g1cxbyoqohn0/hierarchy/your-council/project-updates/clyde-museums/documents/20180824%20Clyde%20Railway%20Station%20Conservation%20Plan.pdf|url-status=live|access-date=31 May 2021|website=www.codc.govt.nz|archive-url=https://web.archive.org/web/20210201184336/https://www.codc.govt.nz/repository/libraries/id:2apsqkk8g1cxbyoqohn0/hierarchy/your-council/project-updates/clyde-museums/documents/20180824%20Clyde%20Railway%20Station%20Conservation%20Plan.pdf |archive-date=1 February 2021 }}</ref>
The Dunstan Trail, a major new cycle route, was opened on the lake's right bank in 2021.<ref> {{cite news|date=14 June 2021|title=Lake Dunstan Cycle Trail|work=[[Stuff (website)|Stuff]] |url=https://i.stuff.co.nz/travel/destinations/nz/central-otago-lakes/300330540/lake-dunstan-cycle-trail-nzs-coolest-coffee-shop-floats-among-the-mountains|access-date=6 July 2021}} </ref>
== Geography == The Cromwell Gorge formed in response to the uplift of the Dunstan and Cairnmuir Mountains and simultaneous [[Antecedent drainage stream|antecedent]] incision by the Clutha River. At the northern (upstream) entrance to the gorge lies the township of Cromwell, while the township of Clyde lies to the south. To the east, the gorge is bound by the [[Dunstan Mountains]] and to the west, the Cairnmuir Mountains. The overall relief from the highest point of the gorge (Leaning Rock, 1647 m) and the floor of the gorge (Lake Dunstan, 194 m) is {{Convert|1453|m|ft|abbr=on}}.
The Cromwell Gorge is the entrance to the [[Upper Clutha Valley]] and was historically an important thoroughfare for early [[Māori people|Māori]] [[moa]] hunters, and later pastoralists and gold miners in the late nineteenth century. It remains an important access route into Central Otago's interior via State Highway 8 (SH8).
=== Geology === The Cromwell Gorge is dominated by the characteristic [[Tor (rock formation)|rocky tors]] and craggy outcrops of the [[Haast Schist|Haast Schist Group]]; grey quartzofeldspathic [[Greywacke|metagreywacke]] interlayered with micaceous meta-argillite and greenschist formed during the [[Rangitata Orogeny]].<ref name="Berryman">{{Cite journal |last1=Beanland |first1=S. |last2=Berryman |first2=K. R. |date=1989 |title=Style and episodicity of late Quaternary activity on the Pisa-Grandview Fault Zone, Central Otago, New Zealand |journal=New Zealand Journal of Geology and Geophysics |volume=32 |issue=4 |pages=451–461 |doi=10.1080/00288306.1989.10427553 |bibcode=1989NZJGG..32..451B |via=Informa|doi-access=free }}</ref> The schist in Central Otago has a well-defined pervasive [[schistosity]], with shallow dips defining the broad regional-scale warps in schistosity caused during [[Miocene]] deformation (the [[Kaikoura orogeny]]).<ref name=":10">{{Cite journal |last=Craw |first=D. |date=1995 |title=Reinterpretation of the erosion profile across the southern portion of the Southern Alps, Mt Aspiring area, Otago, New Zealand |journal=New Zealand Journal of Geology and Geophysics |volume=38 |issue=4 |pages=501–507 |doi=10.1080/00288306.1995.9514676 |bibcode=1995NZJGG..38..501C |via=Informa|doi-access=free }}</ref> The warped geometries are antiformal over mountain ranges and [[synform]]al under the intervening basins.<ref>{{Cite journal |last=Turnbull |first=I. M. |date=1981 |title=Contortions in the schists of the Cromwell district, Central Otago, New Zealand |journal=New Zealand Journal of Geology and Geophysics |volume=24 |issue=1 |pages=65–86 |doi=10.1080/00288306.1981.10422698 |bibcode=1981NZJGG..24...65T |doi-access=free }}</ref> Associated reverse faulting (the [[Otago fault system]]) along the south-eastern flanks of many Central Otago mountain ranges<ref name="Mortimer2023">{{Cite journal |last1=Mortimer |first1=N. |last2=Lee |first2=J. |last3=Stockli |first3=D. F. |date=2023 |title=Terrane and core complex architecture of the Otago Schist in the Dunstan and Cairnmuir Mountains, New Zealand, from U-Pb and (U-Th)/He zircon dating |journal=New Zealand Journal of Geology and Geophysics |pages=1–14 |doi=10.1080/00288306.2023.2176892 |s2cid=257201460 |via=Taylor & Francis Online}}</ref><ref name=":2">{{Cite web |last=Turnbull |first=I. M. |date=2000 |title=Geology of the Wakatipu area : scale 1:250,000 |url=https://shop.gns.cri.nz/qwakatipu-zip/ |access-date=13 August 2023 |website=Institute of Geological and Nuclear Sciences Ltd.}}</ref><ref name="ForsythWaitaki">{{Cite web |last=Forsyth |first=P. J. |date=2001 |title=Geology of the Waitaki area : scale 1:250,000 |url=https://shop.gns.cri.nz/qwaitaki-zip/ |access-date=13 August 2023 |website=Institute of Geological and Nuclear Sciences Ltd.}}</ref> (i.e. [[Taieri Ridge, New Zealand|Taieri Ridge]], [[Lammermoor Range]], [[Rock and Pillar Range]], [[Rough Ridge, New Zealand|Rough Ridge]], [[Raggedy Range, New Zealand|Raggedy Range]], Dunstan Mountains, [[Pisa Range]]) gives rise to the basin and range topography of parallel ridges and basins with steep south-eastern limbs and gently-dipping north-western flanks.<ref name=":9">{{Cite book |last=Ballance |first=P. |url=https://www.geotrips.org.nz/downloads/Ballance_NZ_Geology-V2.pdf |title=New Zealand Geology: An Illustrated Guide |publisher=GSNZ Miscellaneous Publication 148 |year=2009 |isbn=978-0-473-41925-7 |edition=2 |location=Auckland, NZ}}</ref>
The Cromwell Gorge exits the Dunstan and Cairnmuir Mountains immediately to the north of Clyde. Both mountain ranges are controlled to the south-east by large reverse faults; the Dunstan Fault and Earnscleugh Fault, respectively.<ref name="Turnbull87">{{Cite book |last=Turnbull |first=I. M |title=Sheet 133 Cromwell: Geological map of New Zealand. 1:63,360 |publisher=Department of Scientific and Industrial Research |year=1987 |location=Wellington, New Zealand}}</ref><ref name="Barrell">{{Cite book |last=Barrell |first=D. J. A. |url=https://www.orc.govt.nz/media/6621/gns_cr2018-207_queenstown-lakes-and-central-otago_active-faults.pdf |title=General distribution and characteristics of active faults and folds in the Queenstown Lakes and Central Otago districts, Otago |publisher=GNS Science |year=2019 |location=Lower Hutt, NZ |access-date=8 October 2023}}</ref> Investigations have found that geologically-recent deformation associated with the Dunstan Fault has extended south-west towards Clyde, rather than being translated along the southern margin of the Cairnmuir Mountains.<ref name="Barrell" /> This is important as it suggests that there is no recent activity on the transfer zone between the Dunstan and Earnscleugh Faults.<ref name="Barrell" />{{ref|Dagger|†}} This transfer zone is controlled by the well-documented River Channel Fault, a steeply dipping fault mapped as running down the centre of the gorge and directly beneath the Clyde Dam.<ref name="Wanaka2000">{{Cite book |last=New Zealand Geological Survey and Works Consultancy Services |url=https://www.anzgg.org/ANZGG%209%202000%20mid%20conf%20fieldtrip.pdf |title=Clyde Dam Earthquake Investigations |publisher=Electricorp Production |year=1990 |location=Wellington, NZ |access-date=8 October 2023}}</ref> The former Clutha River followed several of these faults as it coursed through the Cromwell Gorge.<ref name="Turnbull87" />
=== Vegetation ===
Vegetation in the Cromwell Gorge has seen considerable change, as has the wider Central Otago region, since at least the [[Holocene]] (10,000 years until present).<ref name=":3">{{Cite journal |last1=Walker |first1=S. |last2=Lee |first2=W. G. |last3=Rogers |first3=G. M. |date=2003 |title=The woody vegetation of Central Otago, New Zealand: its present and past distribution and future restoration needs |url=https://www.doc.govt.nz/documents/science-and-technical/sfc226.pdf |journal=Science for Conservation |volume=226 |access-date=30 September 2023}}</ref> The arrival of humans in Central Otago resulted in particularly extensive changes in vegetation as Māori [[hunter-gatherer]]s used clearance fires improvidently.<ref name=":3" /><ref name=":8">{{Cite journal |last1=Molloy |first1=B. F. |last2=Burrows |first2=C. J. |last3=Cox |first3=J. E. |last4=Johnston |first4=J. A. |last5=Wardle |first5=P. |date=1963 |title=Distribution of subfossil forest remains in eastern South Island, New Zealand. |journal=New Zealand Journal of Botany |volume=1 |issue=1 |pages=68–77 |doi=10.1080/0028825X.1963.10429322 |via=Taylor & Francis Online}}</ref><ref name=":5">{{Cite journal |last=McGlone |first=M. S. |date=2009 |title=Postglacial history of New Zealand wetlands and implications for their conservation |url=https://newzealandecology.org/nzje/2889.pdf |journal=New Zealand Journal of Ecology |volume=33 |issue=1 |pages=1–23 |access-date=8 October 2023}}</ref><ref name=":7">{{Cite journal |last1=McGlone |first1=M. S. |last2=Mark |first2=A. F. |last3=Bell |first3=D. |date=1995 |title=Late Pleistocene and Holocene vegetation history, Central Otago, South Island, New Zealand |journal=Journal of the Royal Society of New Zealand |volume=25 |issue=1 |pages=1–22 |doi=10.1080/03014223.1995.9517480 |bibcode=1995JRSNZ..25....1M |via=Taylor & Francis Online}}</ref><ref name=":11">{{Cite news |last=Nicholls |first=J. |date=15 January 2022 |title=Did moa once browse in huge kōwhai forests in Central Otago? |work=[[Stuff (website)|Stuff]] |url=https://i.stuff.co.nz/environment/127491489/did-moa-once-browse-in-huge-kwhai-forests-in-central-otago |access-date=29 September 2023}}</ref> Early Māori firing of woody cover from about the thirteenth century<ref name=":5" /> resulted in a vastly different vegetation in the Cromwell Gorge. Initial woody cover included [[Podocarpus totara|totara]] (''Podocarpus hallii'') and beech forest (''[[Nothofagus menziesii]]'') over what is now a treeless Central Otago.<ref name=":3" /><ref name=":8" /><ref name=":7" /><ref name=":11" />
Grassland and scrub now cover most of Central Otago. On the former valley floor of the Cromwell Gorge, low [[Tussock grass|tussock]] grassland of several varieties dominated, while [[Leptospermum scoparium|manuka]], [[kānuka]] and [[Discaria toumatou|matagouri]] scrub patched the lower slopes.<ref name="LaythamCromwellGorge" /> Uncontrolled burn-offs, over-grazing, and the introduction of the [[rabbit]] in the mid-1800s,<ref>{{Cite web |title=Rabbits – Rāpeti: Introduction into New Zealand |url=https://my.christchurchcitylibraries.com/rabbits/#:~:text=Introduction%20into%20New%20Zealand,exact%20date%20is%20not%20known. |access-date=8 October 2023 |website=[[Christchurch City Libraries]] }}</ref> have heavily modified the vegetation cover since European settlement. This is further worsened by Central Otago being the driest region in New Zealand.<ref name=":7" /> Those areas of the gorge which are the driest are dominated by cushions of [[Raoulia australis|scabweed]], [[Rosa rubiginosa|sweet briar rosehip]],<ref>{{Cite web |last=Wassilieff |first=M. |date=24 September 2007 |title=Shrublands - Shrublands of dry country |url=https://teara.govt.nz/en/photograph/14540/sweet-briar-rosehips |access-date=7 October 2023 |website=[[Te Ara - the Encyclopedia of New Zealand]] }}</ref> and [[thyme]], all of which flourish. The introduction of thyme to Central Otago is most-often attributed to [[Jean Desire Feraud]], a French [[Placer mining|goldminer]] and [[orchard]]ist who was part of the [[Otago gold rush]].<ref>{{Cite web |last=Grzelewski |first=D. |date=September 2006 |title=Thyme: Thyme on your hands |url=https://www.nzgeo.com/stories/thyme/ |access-date=6 October 2023 |website=New Zealand Geographic}}</ref><ref>{{Cite news |last=Smith |first=C. |date=15 July 2012 |title=Sage man knows it's thyme (+ recipe) |work=[[Otago Daily Times]] |url=https://www.odt.co.nz/lifestyle/food-wine/sage-man-knows-its-thyme-recipe |access-date=7 October 2023}}</ref><ref>{{Cite news |last=Fletcher |first=J. |date=18 January 2018 |title=Southern Stays: Nothing but thyme for Central Otago's historic charm |work=[[Stuff (website)|Stuff]] |url=https://i.stuff.co.nz/travel/destinations/nz/100662516/southern-stays-nothing-but-thyme-for-central-otagos-historic-charm |access-date=7 October 2023}}</ref>
There is evidence of native plant regeneration (such as [[kōwhai]]) in areas where conservation has been put in place,<ref name="LaythamCromwellGorge" /> though its reestablishment in the Cromwell Gorge is not nearly as extensive as the nearby [[Roxburgh Gorge]].<ref>{{Cite web |title=Roxburgh Gorge Flora and Geology |url=https://www.cluthagold.co.nz/plan-your-trip/roxburgh-gorge-flora |access-date=29 September 2023 |website=Clutha Gold}}</ref> Forests of kōwhai (''Sophora microphylla'') have recently been postulated to have also been present in the Cromwell Gorge, upon which moa grazed.<ref name=":11" />
Today in spring and summer the gorge blossoms with wild flowers: the purple of thyme, the blue of [[Echium vulgare|Vipers bugloss]], the red of [[Centranthus ruber|Spur valerian]], and the yellows of [[Eschscholzia californica|Californian poppy]] and [[Sedum|stone crop]].<ref name="LaythamCromwellGorge">{{cite book |last1=Laytham |first1=P. |last2=Laytham |first2=E. |title=The Cromwell Gorge: An Historical Guide |date=1995 |publisher=Cromwell and Districts Promotion Group |location=Cromwell, NZ}}</ref>
== History ==
=== Māori === The first settlers in the region were the Māori as they travelled through Central Otago en route to the [[West Coast Region|West Coast]] on [[pounamu]] expeditions, as well as in search of seasonal food resources.<ref name="Hamel1993">{{cite book |last1=Hamel |first1=G. E. |title=The Rich Fields of Bendigo |date=1993 |publisher=Unpublished report to the Department of Conservation |location=Dunedin, NZ |url=https://dl.heritage.org.nz/greenstone3-foo/library/sites/hnz/collect/pdf-reports/index/assoc/Hamel61.dir/Hamel61.pdf |access-date=22 August 2023}}</ref><ref name=":6">{{Cite web |title=History of Bendigo |url=https://www.doc.govt.nz/parks-and-recreation/places-to-go/otago/places/bendigo-area/history-of-bendigo/ |access-date=20 August 2023 |website=Department of Conservation}}</ref><ref name="Bannockburn">{{cite book |last1=Stephenson |first1=J. |url=https://www.researchgate.net/publication/298685410 |title=Bannockburn heritage landscape study |last2=Bauchop |first2=H. |last3=Petchey |first3=P. |date=2004 |publisher=New Zealand Department of Conservation |isbn=0-478-22603-9 |location=Wellington, NZ |access-date=21 October 2023 |via=ResearchGate}}</ref> Although the [[Lindis Pass]] was the usual route for early Māori to access their summer camps at [[Lake Hāwea]] and [[Lake Wānaka]],<ref name="ThomsonGorgeBrochure">{{cite web |title=Thomson Gorge Road Brochure |url=https://goldfieldstrust.org.nz/wp-content/uploads/Thompson-Gorge-brochure-FOR-WEB-1.pdf |website=Otago Goldfields Heritage Trust |access-date=8 October 2023 |date=February 2007}}</ref><ref>{{Cite book |last=Chinn |first=B. |url=https://www.qldc.govt.nz/media/l5bndghc/s3448-t16-a-pretty-good-place-to-live-hawea-history.pdf |title=A Pretty Good Place to Live: Lake Hawea & Hawea Flat |year=2015}}</ref> there is sufficient evidence the Cromwell Gorge was used as an important thoroughfare.<ref name="Ritchie1982">{{cite journal |last1=Ritchie |first1=N. A. |date=1982 |title=The prehistoric role of the Cromwell Gorge, New Zealand |url=https://nzarchaeology.org/download/the-prehistoric-role-of-the-cromwell-gorge-new-zealand |journal=New Zealand Journal of Archaeology |volume=4 |pages=21–43 |access-date=28 September 2023}}</ref> Early Māori archaeological sites are concentrated through the gorge, particularly on the true left of the former Clutha River,<ref name="HamelArchaeologyofOtago">{{Cite book |last=Hamel |first=Jill |url=https://www.doc.govt.nz/globalassets/documents/science-and-technical/the_achaeology_of_otago_jill_hamel_web.pdf |title=The Archaeology of Otago |publisher=Department of Conservation |year=2001 |isbn=0-478-22016-2 |location=Wellington, New Zealand |access-date=21 August 2023}}</ref><ref>{{cite web |last1=Ministry of Energy, Electricity Division |date=1978 |title=Archaeology: Clutha Valley Development |url=https://dl.heritage.org.nz/greenstone3-foo/library/sites/hnz/collect/pdf-reports/index/assoc/Ministry/1.dir/Ministry1.pdf |access-date=30 September 2023 |website=Archaeological Reports Digital Library, Heritage New Zealand Pouhere Taonga |publisher=New Zealand Historic Places Trust |location=Wellington, NZ}}</ref> and include small [[moa]] hunter camps with associated moa bones. Four sites have been identified at Rockfall I and II, Italian Creek, Muttontown Gully and Clyde West.<ref name="Ritchie1982" /><ref name="HamelArchaeologyofOtago" />
Evidence for Māori occupation of specific sites in the Cromwell Gorge was well-documented during the Clutha Valley Archaeological Project resulting from the decision to build the Clyde Dam. Despite the limited number of samples available, rock shelters and adjacent sites showed the following finds to be culturally significant:<ref name="Ritchie1982" />
==== Italian Creek ==== [[File:Cromwell Gorge Map.png|thumb|300 px|Map of the Cromwell Gorge illustrating Lake Dunstan, the Clyde Dam, faults and landslides.]] * ({{Coord|-45.1175|169.3146|display=inline}}) * [[Eel]] net (''purangi'') which may have been abandoned in transit, or left with the expectation of returning for it * Cooked remains of a [[Kākā]] * Moa bone and egg shell fragments
==== Rockfall I & II ====
* ({{Coord|-45.0797|169.2365|display=inline}}) * Two prehistoric occupations * Oven-charcoal identifications * [[Tuatara]] bone fragments * Moa bone and egg shell fragments
==== Muttontown Gully ====
* ({{Coord|-45.14827|169.31279|display=inline}}) * A slab of [[flint]] from which about one dozen flakes lying beside it had been chipped
It has been suggested<ref>{{Cite journal |last=Hamel |first=G. E. |date=1979 |editor-last=Anderson |editor-first=A. J. |title=The breeding ecology of moas |journal=British Archaeological Reports International Series |series=Birds of a Feather |volume=62 |pages=61–66}}</ref> that the numerous overhangs within the craggy rock formations of the Central Otago river gorges may have been favoured moa nesting locations. Such locations abound in the Cromwell Gorge and eggshell fragments found in many shelters confirm their usage.<ref name="Ritchie1982" /> If early Māori hunters recognised such a regularity in moa ecology, it seems likely that they would undertake seasonal or regular raids on nesting areas.
=== European settlement === The first European to set eyes on the Cromwell Gorge was [[Nathanael Chalmers]] who first traversed the valley in 1853,<ref name="LaythamCromwellGorge" /><ref name="Bannockburn" /><ref name="Temple" /><ref>{{Cite web |last=Johnston |first=C. |date=28 March 2010 |title=Third leg of Upper Clutha track ready |url=https://www.stuff.co.nz/southland-times/news/3514596/Third-leg-of-Upper-Clutha-track-ready |access-date=21 October 2023 |website=[[Stuff (website)|Stuff]] }}</ref> accompanied by two Māori guides: Reko, a [[Ngāi Tahu]] chief from [[Tuturau]],<ref>{{Cite web |title=Reko Private Guides: About |url=https://www.reko.co.nz/about/ |access-date=21 October 2023 |website=Reko Private Guides}}</ref> and Kaikōura, a man who had run away from the [[Kaikōura]] ranges.<ref name="Temple">{{Cite book |last=Temple |first=P. |title=New Zealand Explorers : Great Journeys of Discovery |publisher=Whitcoulls |year=1985 |edition=1st |location=Christchurch, New Zealand}}</ref>
Chalmers made his trip into Central Otago's interior when no roads or tracks existed, hoping to retrace the steps that his guide, Reko, had made from the [[Waitaki River|Waitaki]] some twenty years earlier.<ref name="Temple" /> The trek from the [[Mataura River]] in [[Southland Region|Southland]] to Waitaki was some {{Convert|400|km|mi|abbr=on}} distance, climbing mountain passes in excess of {{Convert|1000|m|ft|abbr=on}} {{Ndash}} something Chalmers was blissfully ignorant of ahead of his expedition. Unfortunately for Chalmers, he contracted a bout of chronic diarrhoea early into his trip and suffered with it for many weeks.<ref name="Temple"/> Having eventually made it as far as Lakes [[Lake Wakatipu|Wakatipu]], Hāwea and Wānaka, his illness got the better of him and he realised he would not be able to make it to Waitaki.<ref name="Temple" /><ref name="Bannockburn" />
In a letter to historian [[Herries Beattie]], Chalmers recorded his account of the journey (some fifty seven years after the fact) stating that the shortest way back to Southland would be to build a [[Flax in New Zealand|flax]] fibre ''mokihi'' or raft and ride it all the way down the Clutha River. As they set off from Lake Hāwea and entered the Clutha Rive, Chalmers wrote that they:
{{Blockquote|text=... paddled down the river so rapidly that I could hardly credit our speed|author=Nathanael Chalmers, 1910<ref name="Temple"/>}}
Within half a day, they came to the Clutha's junction with the Kawarau River, leading Chalmers to write:
{{Blockquote|text=The water flow almost doubled and was suddenly confined in the great Cromwell Gorge ... I shall never forget the "race" through the gorge ... my heart was literally in my mouth, but those two old men seemed to care nothing for the current.|author=Nathanael Chalmers, 1910<ref name="Temple"/>}}
When they emerged from the gorge at the site of the present-day Clyde Dam, he wrote "''then our troubles were over''".
Chalmers' early foray into Central Otago was closely followed in the mid 1850s by early pastoralists and runholders searching for sheep grazing land in the vast, trackless interior.<ref name="Bannockburn"/><ref name="LaythamCromwellGorge" /> It was only after surveyor [[John Turnbull Thomson]] and [[Alexander Garvie]] lead a reconnaissance survey of the region in 1857-58, that pastoralists moved into the area in earnest; within a year of Turnbull's survey some {{convert|4|e6acre|e6ha|abbr=on}} had been applied for.<ref name="Bannockburn" />
=== Gold === The Cromwell Gorge was the site of Central Otago's first gold rush into the region's interior and followed soon after the discovery of gold at [[Gabriel's Gully]] near [[Lawrence, New Zealand|Lawrence]]. The initial rush to the gorge, referred to as the Dunstan goldfield, began on 16 August 1862 following an announcement in the ''Otago Daily Times'' that two men, [[Horatio Hartley|Hartley]] and [[Christopher Reilly|Reilly]], had discovered 87 lb (1044 t oz) of gold.<ref name="CluthaPower" />
The winter of 1862 was exceptionally severe and resulted in unseasonably low-levels of the Clutha River.<ref name="DNZB Hartley">{{Cite web |last=Hearn |first=T. J. |date=1990 |title=Hartley, Horatio |url=https://teara.govt.nz/en/biographies/1h11/hartley-horatio |access-date=23 April 2017 |website=[[Te Ara: The Encyclopedia of New Zealand]] }}</ref><ref name="Joyce">{{Cite book |last=Joyce |first=L. |url=http://promotedunstan.org.nz/Files/Gold%20Rush%20final%2014-12-11.pdf |title=Gold Rush: Central Otago 1862 |publisher=Promote Dunstan Inc |year=2012 |isbn=978-0-473-20171-5 |location=Clyde, NZ |ref=Joyce2012}}</ref> [[Horatio Hartley]] and [[Christopher Reilly]] worked the sides of the Cromwell Gorge for three months until they were forced to take the huge hoard of gold they had secretly amassed to the Chief Gold Receiver in [[Dunedin]] in August 1862.<ref>{{Cite web |title=Hartley and Reilly |url=https://centralotagonz.com/tracks-and-trails/lake-dunstan-trail/stories/hartley-and-reilly/ |access-date=16 September 2023 |website=Central Otago District Council}}</ref> Hartley and Reilly's discovery caused great excitement as they deposited some {{Convert|87|lb|oz|abbr=on}} of gold,<ref>{{Cite news |date=26 August 1862 |title=The Eighty Seven Pounds Weight of Gold! |volume=XVII |pages=3 |work=Wellington Independent |issue=1758 |url=https://paperspast.natlib.govt.nz/newspapers/WI18620826.2.13}}</ref> sparking a gold rush to what would become known as [[Hartley's Beach]].<ref>{{Cite news |date=17 August 1889 |title=Saturday, August 17, 1889 |volume=LXXII |pages=4 |work=The Lyttelton Times |issue=8874 |url=https://paperspast.natlib.govt.nz/newspapers/LT18890817.2.24 |access-date=16 September 2023}}</ref> Hartley and Reilly, in divulging the location of their rich finds (approximately one mile downstream of the Clutha River's confluence with the Kawarau River), were rewarded with £2000 from the Otago Provincial Government.<ref>{{Cite news |date=19 August 1862 |title=Conditions of Reward |pages=5 |work=[[Otago Daily Times]] |issue=217 |url=https://paperspast.natlib.govt.nz/newspapers/ODT18620819.2.13.2 |access-date=16 September 2023}}</ref> On 23 September 1862 the Dunstan goldfield was proclaimed, the selection of this name in preference to Hartley's being largely in deference to Reilly, who was 'jealous of the pre-eminence' accorded Hartley as the discoverer.<ref name="DNZB Hartley" />
Within days of the announcement of Hartley and Reilly's discovery, 2000 miners had descended on the Dunstan goldfield with the first gold export to leave the goldfield on 6 October 1862 carrying some 6030 t oz (187.5 kg) of gold.<ref name="CluthaPower" /> Between 1 September 1862 and 1 April 1863, 120,886 t oz (3760 kg) of gold were recovered from Otago, with most of this coming from the Dunstan goldfield.<ref name="CluthaPower" /> By the end of 1864 the easily won gold had been mined and many had moved off to other more lucrative fields.
==== Dredges ==== [[File:Hartley_and_Reilly_Dredge,_Cromwell_Gorge.jpg|thumb|300 px|Construction of the Hartley and Reilly Dredge next to the Clutha River in the Cromwell Gorge, 1890s]]
At the turn of the twentieth century, the gorge would once again see a feverish gold rush, but this time on a more industrial scale as large mechanical dredges made large returns. In 1900 there were 187 dredges being operated on the Clutha River,<ref>{{Cite web |title=Gold Dredges Development |url=https://www.engineeringnz.org/programmes/heritage/heritage-records/gold-dredges-development/ |access-date=19 October 2023 |website=Engineering New Zealand}}</ref> but like the earlier gold rush, the times of the dredges drew to a close only several years later.
==== Chinese miners ==== In 1865, the Otago Provincial Council invited Chinese miners working on the [[Victorian Goldfields|Victorian goldfields]] in Australia, to rework the Otago goldfields.<ref name=":12">{{Cite web |title=Chinese Miners |url=https://www.cromwellmuseum.nz/chinese-miners |access-date=19 October 2023 |website=Cromwell Museum}}</ref> European miners had departed in their droves for more lucrative goldfields in [[Marlborough District|Marlborough]] and the [[West Coast gold rush|West Coast]], opening the door for Chinese mining immigrants to come directly from China, particularly [[Guangdong]] province.<ref name=":12" />
Many mined in the gorge where they lived a hard life in harsh conditions, often in rock shelters. The first camp established was near Gibraltar Rock ({{Coord|-45.0773|169.2329}}) in the Cromwell Gorge,<ref name="LaythamCromwellGorge" /><ref name=":12" /> although a far more substantial settlement in the 1870s formed Cromwell's ''Chinatown''. Deserted by the turn of the century, the wooden stores and businesses were demolished in 1930.<ref name=":12" />
Chinese were not always popular or welcome, and often blamed for things they did not do.<ref name="LaythamCromwellGorge" /> This was made more problematic due to the manner by which they were initially invited to New Zealand; the Chinese regarded themselves as temporary visitors seeking gold. As such they tended to have little interaction with Europeans,<ref name=":12" /> and the importance of their place in Central Otago's history has often been overlooked.
=== Railway === A railway to Cromwell had been proposed at least as early as 1877,<ref>{{Cite news |date=8 August 1877 |title=South Invercargill |pages=2 |work=[[Southland Times]] |issue=2853 |url=https://paperspast.natlib.govt.nz/newspapers/ST18770808.2.9 |access-date=9 October 2023 |via=Papers Past}}</ref> although it was intended to link the Lakes District ([[Kingston, New Zealand|Kingston]]/[[Queenstown, New Zealand|Queenstown]]) via the Kawerau Gorge and not the Cromwell Gorge at the time.<ref>{{Cite news |date=22 November 1877 |title=General Assembly |volume=8 |pages=3 |work=Globe |issue=1062 |url=https://paperspast.natlib.govt.nz/newspapers/GLOBE18771122.2.19 |access-date=9 October 2023 |via=Papers Past}}</ref> Reference to a railway, presumably through the Cromwell Gorge, linking to the Taieri Railway was also made in 1877,<ref>{{Cite news |date=27 December 1877 |title=Lake Wakatip |volume=8 |pages=3 |work=Mount Ida Chronicle |issue=452 |url=https://paperspast.natlib.govt.nz/newspapers/MIC18771227.2.8 |access-date=9 October 2023 |via=Papers Past}}</ref> but nothing would come of this for another thirty years.
The railway finally made it as far as Clyde in 1907, with the station's official opening on 2 April 1907 by the prime minister, [[William Hall-Jones]].<ref>{{Cite news |date=9 March 1907 |title=Otago Central Railway |pages=10 |work=[[Otago Daily Times]] |issue=13847 |url=https://paperspast.natlib.govt.nz/newspapers/ODT19070309.2.86 |access-date=9 October 2023}}</ref> The Cromwell Railway and Progress League, having been formed in 1906 to influence the extension of the railway through the gorge to Cromwell,<ref>{{Cite news |date=12 February 1906 |title=Cromwell Railway League Meeting |volume=37 |pages=5 |work=Cromwell Argus |issue=1975 |url=https://paperspast.natlib.govt.nz/newspapers/CROMARG19060212.2.19 |access-date=9 October 2023 |via=Papers Past}}</ref> set about lobbying the Government with increasing frequency. However, work on the railway line stopped at Clyde until 1914.<ref>{{Cite web |title=The Cromwell Gorge Railway |url=https://mightyclutha.blogspot.com/2009/08/cromwell-gorge-railway.html |access-date=21 October 2023 |website=Mighty Clutha - Otago's Stolen Treasure}}</ref> The lobby group stressed the high cost of transport between Cromwell and Clyde, the impact on the region's farmers and also pointed to the inadequacies of the road:<ref name="LaythamCromwellGorge" />{{Blockquote|text=The road through the gorge is a narrow one, with some very sharp bends, and at the best of times it is dangerous with a considerable amount of horse traffic, and an accident at any point of the gorge means sudden death.|author=Otago Central Railway League|source=''Evening Star'', 24 February 1911<ref name="LobbyGp">{{Cite news |date=24 February 1911 |title=Otago Central |pages=1 |work=Evening Star |issue=14497 |url=https://paperspast.natlib.govt.nz/newspapers/ESD19110224.2.3 |access-date=15 October 2023 |via=Papers Past}}</ref>}}
"Irrigation first", was the Government's reply,<ref name="LobbyGp" /> reflecting their desire to harness the economic benefits of the Country's nascent agricultural potential. The Government's response was nothing new, having espoused this priority since at least 1899.<ref>{{Cite news |last=Nichol |first=D. |date=1 March 1899 |title=Otago Central Railway |pages=7 |work=[[Otago Daily Times]] |issue=11360 |url=https://paperspast.natlib.govt.nz/newspapers/ODT18990301.2.78 |access-date=15 October 2023 |via=Papers Past}}</ref> This would not stop the representations, however.
An announcement to restart the railway extension was made in March 1914,<ref>{{Cite news |date=10 March 1914 |title=Minister of Works |pages=8 |work=Evening Star |issue=15483 |url=https://paperspast.natlib.govt.nz/newspapers/ESD19140310.2.84 |access-date=21 October 2023 |via=Papers Past}}</ref> and works were established in the following months with new surveys taking place.<ref>{{Cite news |date=4 May 1914 |title=[Untitled] |pages=6 |work=[[Otago Daily Times]] |issue=16189 |url=https://paperspast.natlib.govt.nz/newspapers/ODT19140926.2.37 |access-date=21 October 2023 |via=Papers Past}}</ref> The railway started in earnest in September<ref name=":13">{{Cite news |date=26 September 1914 |title=[Untitled] |pages=4 |work=Evening Star |issue=15483 |url=https://paperspast.natlib.govt.nz/newspapers/ESD19140504.2.25 |access-date=21 October 2023 |via=Papers Past}}</ref> and by the end of 1916 some {{convert|8.5|mi|km|abbr=on}} of rail had been laid.<ref>{{Cite news |date=18 December 1916 |title=Radium for the Teeth |pages=2 |work=Dunstan Times |issue=2846|url=https://paperspast.natlib.govt.nz/newspapers/DUNST19161218.2.6 |access-date=21 October 2023 |via=Papers Past}}</ref> The line to Cromwell was not completed until July 1921<ref>{{Cite news |date=11 July 1921 |title=Opening of Railway |pages=4 |work=Dunstan Times |issue=3077 |url=https://paperspast.natlib.govt.nz/newspapers/DUNST19210711.2.15 |access-date=21 October 2023 |via=Papers Past}}</ref> {{Ndash}} significantly overrunning the predicted two to three years it would take.<ref name=":13" /> An [[E class (Double Fairlie locomotive)]], ''Josephine'', which pulled all the trains in the gorge during the construction era, is now a museum piece in the [[Otago Settlers Museum]].
Cromwell was the terminus of the Otago Central Railway and consisted of a railway station building, five staff houses, a 6000 gallon locomotive watering tank, stockyards, an engine-shed, turntable coal facilities and the station sidings were able to accommodate nearly 100 wagons.<ref name="LaythamCromwellGorge" /><ref name=":14" /> At the time, it was by far the most economic way to get the region's produce to Dunedin and was a boon for the runholders of Waenga Station and the orchardists in the gorge.
With the coming of the Clyde dam, the Cromwell-Clyde railway was closed in 1980.<ref name=":14">{{Cite web |title=The Cromwell Gorge Railway |url=https://mightyclutha.blogspot.com/2009/08/cromwell-gorge-railway.html |access-date=6 October 2023 |website=Mighty Clutha {{ndash}} Otago's Stolen Treasure}}</ref> When the dam itself was completed, the line to Clyde had little other traffic and the section from [[Middlemarch, New Zealand|Middlemarch]] to Clyde was closed on 30 April 1990.<ref name=":14" /> The line beyond Middlemarch was lifted during 1991, and the track-bed as far as Clyde was handed over to the Department of Conservation in 1993, becoming the [[Otago Central Rail Trail]].
=== Orchards === [[Orchard]]ists moved to the gorge because of its frost-free springs.<ref name="LaythamCromwellGorge" /> Orchards, grown on both sides of the Clutha River, primarily produced stone fruits (particularly apricots, cherries, nectarines, peaches, plums) as well as a number of varieties of apples and pears. The Cromwell Gorge had a [[microclimate]] that meant that orchardists would not need to burn [[Smudge pot|smoke pots]] to save the fruit from spring frosts and importantly, the crop ripened ahead of the apricots grown in orchards in (e.g.) [[Earnscleugh]] or Cromwell.<ref name="LaythamCromwellGorge" /><ref name="ODTClyeDam" /><ref name="MightyCluthaOrchard">{{cite web |title=Lost Orchards and Farmland |url=https://mightyclutha.blogspot.com/2009/01/lost-orchards.html |website=Mighty Cutha |access-date=7 October 2023}}</ref> This made the Cromwell Gorge unique in the region and subsequently it produced some of New Zealand's best fruit.<ref name="JackonsOrchard">{{cite web |title=About Us |url=https://www.jacksonorchard.co.nz/pages/about-us |website=Jackson Orchards. Kevin Jackson Family Trust |access-date=7 October 2023}}</ref>
The Annan's were one of the first families to establish an orchard at the southern end of the gorge on what would become Fruitgrowers Road. In 1901 William Annan cleared his piece of land, built a cob shelter, and planted his fruit trees.<ref name="LaythamCromwellGorge" /><ref name="NatGeo">{{Cite web |title=Farewell to the Clutha |url=https://www.nzgeo.com/stories/farewell-to-the-clutha/ |access-date=23 October 2023 |website=New Zealand Geographic}}</ref> Imported from Australia, the first trees Annan planted were a diverse mix to test what would be most suitable for the challenging Central Otago climate and included citrus, almond, walnut, cherry, apricot, apple, pear, peach, nectarine, quince and grape.<ref name="NatGeo"/> By 1914 he had a healthy orchard and was mentioned in the ''Evening Star'' as part of an exhibition of fruit from Central Otago.<ref>{{cite news |title=Gala Week |url=https://paperspast.natlib.govt.nz/newspapers/ESD19140323.2.35 |access-date=14 October 2023 |issue=15448 |publisher=Evening Star |date=23 March 1914 |page=6|via=Papers Past}}</ref>
The last orchardist to leave the Cromwell Gorge ahead of inundation by Lake Dunstan, was Kevin Jackson, who had run an orchard in the gorge from 1969{{Ndash}}1989.<ref name="JackonsOrchard" /> Jackson and many others whose livelihoods would be irrevocably damaged by the filling of the dam challenged the Government, but to no avail.<ref name="MightyCluthaOrchard" /><ref>{{Cite news |date=20 July 1977 |title=Dam plan to be tested |pages=11 |work=Press |url=https://paperspast.natlib.govt.nz/newspapers/CHP19770720.2.87 |access-date=22 October 2023 |via=Papers Past}}</ref><ref>{{Cite news |date=9 June 1977 |title=[Untitled] |pages=11 |work=Press |url=https://paperspast.natlib.govt.nz/newspapers/CHP19770609.2.132.3 |access-date=22 October 2023 |via=Papers Past}}</ref><ref>{{Cite news |date=22 July 1978 |title=Clutha agreement |pages=20 |work=Press |url=https://paperspast.natlib.govt.nz/newspapers/CHP19780722.2.115 |access-date=22 October 2023 |via=Papers Past}}</ref> Only a few trees from what was Jackson's orchard ({{Coord|45.0852|169.2637}}) still remain at the edge the lake.<ref name="LaythamCromwellGorge" />
The reservoir behind the Clyde dam flooded a total of {{Convert|2300|ha|acre|abbr=on}} of productive land, including twelve large orchards on the river terraces along both sides of the Cromwell Gorge, five orchards at Lowburn, and fertile farmlands on both sides of the Clutha River in the Lowburn area.<ref name="MightyCluthaOrchard" />
== Clyde Dam project == Initial thoughts on harnessing the Clutha River for hydroelectric power occurred at least as early as 1904,<ref name="McElroy">{{cite book |last1=McElroy |first1=E. J. |title=An Analysis of Planning Procedures Associated with the Development of the Cromwell Town Plan |date=1982 |publisher=Otago University (PGDip Thesis) |location=Dunedin, NZ |url=https://ourarchive.otago.ac.nz/bitstream/handle/10523/11832/McElroyElissaJ1982Dip.pdf?sequence=1&isAllowed=y |access-date=15 October 2023}}</ref> but it was not until the 1940s that it began to be a more serious option for power in Otago.<ref name=":1">{{Cite news |date=31 October 1945 |title=Key to Progress: South Island's Power Resources |pages=4 |work=[[Otago Daily Times]] |issue=25988 |url=https://paperspast.natlib.govt.nz/newspapers/ODT19451031.2.22 |access-date=15 October 2023 |via=Papers Past}}</ref><ref name="CluthaPower">{{cite book |last1= |url=https://archive.org/details/clyde-dam-clutha-power |title=Clyde Dam: Clutha power |date=1987 |publisher=Ministry of Works and Development |location=Wellington, NZ |pages=15 |access-date=30 September 2023}}</ref> An examination of the Clutha River's potential in 1944 culminated in the selection and construction of the [[Roxburgh Dam]] with first power being produced in 1956.<ref name=":1" /> By 1968, the Government felt that the Clutha River was under-utilised, especially in comparison to the [[Waitaki River]] which by this time had the Waitaki Dam, [[Benmore Dam]] and [[Aviemore Dam]]. The same year, a committee was setup to investigate additional hydroelectric options on the Clutha River and by 1971 had come up with six potential options (Schemes A through F).<ref name="McElroy" /> These would later (1973) be added to by several additional schemes, in particular Scheme H which called for a low dam at Clyde that would minimise the size of the reservoir. The [[New Zealand Labour Party|Labour Government]] in 1975 selected Scheme H but a change in government to [[Robert Muldoon|Robert Muldoon's]] [[New Zealand National Party|National Party]] in 1976 reversed this decision, opting instead for Scheme F, a high dam to be built at Clyde which would impact the Cromwell Gorge, Cromwell, the Kawerau Arm and [[Lowburn]].<ref name="Nathan"/><ref>{{Cite news | date=12 June 1982 |title=Clyde dam — background to a contentious issue |pages=16 |work=Press |url=https://paperspast.natlib.govt.nz/newspapers/CHP19820612.2.97 |access-date=18 October 2023 |via=Papers Past}}</ref> The impact on existing activities from any scheme was recognised from the outset:
{{Blockquote|text=Any further Clutha Valley development poses a very complex problem as there are considerable areas of better lands, orchards, allied industries, communication routes, closer settlement, and whole townships or effects on townships and local bodies to be taken into account.|author=''Upper Clutha Hydro-Electric Interdepartmental Committee'', December 1971<ref name="McElroy"/>}}
Protests that the dam would flood established orchards, the railway, State Highway 8 as well as parts of Cromwell<ref>{{Cite news | date=12 April 1975 |title=Central Otago river valleys rule many lives |volume=115 |issue=33816 |pages=11 |work=Press |url=https://paperspast.natlib.govt.nz/newspapers/CHP19750412.2.100 |access-date=18 October 2023 |via=Papers Past}}</ref> were all ignored with the high dam becoming part of the National Government's ''[[Think Big]]'' policy.<ref name="Nathan"/>
===Clyde Dam===
[[File:Clyde Dam with Power Station.jpg|thumb|300 px|Clyde Dam with Power Station]] Construction of the Clyde Dam was started in 1977 and first required the excavation of a diversion channel for the Clutha River. The diversion channel was cut down {{Convert|22|m|ft|abbr=on}} into the gravel and bedrock on the true right bank of the river. At {{Convert|50|m|ft|abbr=on}} wide and {{Convert|700|m|ft|abbr=on}} long,<ref name="CluthaPower" /> it facilitated the safe construction of the remainder of the dam. The river was diverted in 1982, at which point temporary [[Cofferdam|coffer dams]] had been conducted to enable building of the dam's concrete superstructure. A cable crane attached to pylons delivered the majority of the {{Convert|1.2|e6m3|e6cuft|abbr=on}} of concrete required to build the dam and its associated powerhouse. At its peak between 1986 and 1987, approximately 1000 dam workers were on site.<ref name="CluthaPower" /> The dam was completed in 1990,<ref name="ODTClyeDam">{{Cite news |last=Gilchrist |first=S. |date=2 January 2010 |title=Reflections on Lake Dunstan |work=[[Otago Daily Times]] |url=https://www.odt.co.nz/lifestyle/magazine/reflections-lake-dunstan |access-date=26 September 2023}}</ref> however it was not commissioned until 1992<ref name="Contact">[http://www.contactenergy.co.nz/web/pdf/environmental/Hydro_brochure.pdf Hydroelectricity: turning water into power]{{Webarchive|url=https://web.archive.org/web/20100524013207/http://www.contactenergy.co.nz/web/pdf/environmental/Hydro_brochure.pdf |date=2010-05-24}}, Contact Energy.</ref> at a total cost of $955M NZD (September 1987).<ref name="CluthaPower" /> The cost of the dam was made up of [[Ministry of Works and Development]] civil works for Clyde: $591 million; [[Electricity Corporation of New Zealand|Electricorp]] works, Clyde: $175 million; road realignment works: $100 million; property compensation: $24 million; Cromwell Township: $65 million. The roadworks figures would later significantly inflate due to costs incurred during landslide stabilisation in the gorge.
Work during the dam's early construction phase in 1982 identified numerous faults and [[shear zone]]s beneath the dam {{Ndash}} in particular, the River Channel Fault.<ref name="Wanaka2000" /><ref name="MightyCutha">{{cite web |title=Clyde Dam |url=https://mightyclutha.blogspot.com/search/label/Clyde%20dam |access-date=30 September 2023 |website=Mighty Cutha}}</ref> Despite considerable amounts of concrete being pumped into tunnels across the fault to act as shear pins,<ref name="MightyCutha" /> the faults posed a significant risk and forced a redesign of the dam leading to the incorporation of a controversial ''slip joint''. The slip joint is designed to accommodate up to {{convert|2|m|ft|abbr=on}} of lateral fault movement and {{convert|1|m|ft|abbr=on}} of vertical movement.<ref name="CluthaPower" /><ref name="MightyCutha" /> Geologists at the time considered there was a low to very-low possibility of movement along the Dunstan Fault upstream of the dam in the event of a major earthquake; such a movement could lead to up to {{convert|200|mm|in|abbr=on}} of relative movement on the River Channel Fault at the dam site.<ref name="CluthaPower" />
===Cultural and archaeological losses=== The filling of the Clyde Dam resulted in the loss of significant sites of cultural interest in the Cromwell Gorge and other areas inundated by Lake Dunstan. Knowing this would be the case, the Ministry of Works commissioned archaeological surveys of the gorge and surrounding areas that would be impacted by the filling of Lake Dunstan. The initial studies in 1976{{Ndash}}1977 revealed that more than 150 sites would be affected by the filling of the proposed dam(s) in the Cromwell Gorge.<ref name="Ritchie1989" /> Given the large number of sites affected, a project archaeologist was employed for an initial period of five years, which was later increased to ten years due to the sheer enormity of excavating and cataloguing the sites which would be impacted by the damming of the Clutha River.<ref name="Ritchie1989" /><ref name="CluthaPower" />
Unlike the Roxburgh Gorge, where no archaeological survey was ever undertaken before the Roxburgh Dam was built, the Cromwell Gorge would reveal a rich wealth of mining era (1862-1890) and some pre-European sites. In all, 44 rock shelters were recorded in the Cromwell Gorge.<ref name="Ritchie1989" />
Over the duration of the project, approximately 2000 sites were added to the national site recording scheme with almost every farm in the Upper Clutha being systematically surveyed.<ref name="Ritchie1989" /><ref name="CluthaPower" />
Perhaps the greatest site of interest of the entire ten-year project was the excavation of Cromwell's Chinatown at the confluence of the Clutha and Kawarau Rivers.<ref name="CluthaPower" /> The site had been abandoned since the 1920s when it was excavated over a 10-week period in 1980, many of the artifacts going on display in the Cromwell Museum.<ref name="CluthaPower" />
Ritchie (1989)<ref name="Ritchie1989">{{cite web |last1=Ritchie |first1=N. A. |date=1989 |title=The Clutha Archaeological Project: 1977-1987. A Summary Report |url=https://dl.heritage.org.nz/greenstone3-foo/library/sites/hnz/collect/pdf-reports/index/assoc/Ritchie1/3.dir/Ritchie13.pdf |access-date=30 September 2023 |website=Archaeological Reports Digital Library, Heritage New Zealand Pouhere Taonga |publisher=New Zealand Historic Places Trust}}</ref> presented a compilation of 617 sites of archaeological significance, 85 of which were submerged in the Cromwell Gorge due to the filling of Lake Dunstan. A total of 250 sites were lost in the greater Lake Dunstan area due to the filling of the lake.<ref name="CluthaPower" />
<mapframe latitude="-45.05" longitude="169.21" zoom="14" width="300" height="200" align="right" text= "Archaeological sites near and flooded by Lake Dunstan. Data source: Ritchie (1989)"> { "type": "ExternalData", "service": "page", "title": "LakeDunstanArcheologySites1987.map", } </mapframe>
===Landslides=== [[File:Cairnmuir Landslide Buttresses.jpg|thumb|300 px|View of the Cairnmuir Landslide stabilisation terraces (drainage blanket) in the Cromwell Gorge]]
Large-scale [[landslide]]s are a common feature in the Cromwell Gorge and represent a significant [[geological hazard]] following the [[Dam|impoundment]] of the Clutha River behind the Clyde Dam. Seventeen large schist landslides have been mapped along the length of the gorge.<ref name="Turnbull87" /><ref name="OBrien">{{Cite journal |last1=O'Brien |first1=G. A. |last2=Cox |first2=S. C. |last3=Townend |first3=J. |date=2016 |title=Spatially and temporally systematic hydrologic changes within large geo-engineered landslides, Cromwell Gorge, New Zealand, induced by multiple regional earthquakes |journal=J. Geophys. Res. Solid Earth |volume=121 |issue=12 |pages=8750–8773 |doi=10.1002/2016JB013418 |s2cid=133979788 |url=https://figshare.com/articles/journal_contribution/13819244 |via=AGU}}</ref> These landslides underwent extensive [[Geotechnical engineering|geo-engineering]] in the early 1990s to mitigate their movement,<ref name="OBrien" /><ref name="Nathan">{{Cite journal |last=Nathan |first=S. |date=2021 |title=Geology and the Clyde Dam |url=https://www.researchgate.net/publication/349162756 |journal=Geoscience Society of New Zealand Journal of the Historical Studies Group |volume=68 |pages=42–52 |via=ResearchGate}}</ref> and all now have extremely low movement rates as a result.<ref name="OBrien" /><ref name="Petley">{{Cite web |last=Petley |first=D. |date=15 July 2020 |title=Cromwell: helicopter sluicing to manage a landslide |url=https://blogs.agu.org/landslideblog/2020/07/15/cromwell/ |access-date=20 August 2023 |website=AGU Blogosphere}}</ref> Engineering works included extensive drainage to draw down the groundwater level, toe buttresses and in the case of the Cairnmuir Landslide, a drainage blanket. Thirteen large-diameter tunnels extend into the toes of several landslides in order to drain groundwater which otherwise lubricates the basal shear zone. Combined with smaller drainage tunnels (49 in total),<ref>{{Cite book |last=O'Brien |first=G. |url=http://researcharchive.vuw.ac.nz/handle/10063/3454 |title=Earthquake-induced hydrologic changes in the geoengineered schist landslides of Cromwell Gorge, Central Otago |publisher=Masters Thesis, Victoria University |year=2014 |location=Wellington, New Zealand}}</ref> the total extent of the tunnels is {{Convert|18.5|km|mi|abbr=on}}.<ref>{{Cite news |last=Edwards |first=J. |date=30 March 2016 |title=Hundreds venture underground to slip zone |work=[[Otago Daily Times]] |url=https://www.odt.co.nz/regions/central-otago/hundreds-venture-underground-slip-zone |access-date=22 August 2023}}</ref> In addition to the mitigation measures, some 6500 instruments have been installed to measure and monitor slide movement.<ref name="Contact" />
On 13 July 2020 a new slip near Cromwell occurred above [[Deadman's Point Bridge]] on the true left of Lake Dunstan. The difficulty in accessing the slip resulted in a rather novel remediation technique; helicopters with [[Helicopter bucket|monsoon buckets]] were used to sluice loose material and dislodge unstable rock by dropping large quantities of water directly onto the slip.<ref name="Petley"/><ref>{{Cite web |date=15 July 2020 |title=Cromwell slip site – road to continue as single lane, sluicing ongoing today and next few days |url=https://www.nzta.govt.nz/media-releases/cromwell-slip-site-road-to-continue-as-single-lane-sluicing-ongoing-today-and-next-few-days/ |access-date=20 August 2023 |website=Waka Kotahi NZ Transport Agency}}</ref><ref>{{Cite news |last=McKenzie-McLean |first=J. |date=15 July 2020 |title=Choppers sluicing unstable Otago highway rockface after massive slip |work=[[Stuff (website)|Stuff]] |url=https://www.stuff.co.nz/national/122139164/choppers-sluicing-unstable-otago-highway-rockface-after-massive-slip |access-date=20 August 2023}}</ref><ref name="New Zealand Herald">{{Cite news |date=13 July 2020 |title=Choppers sent in as massive landslip closes road in Cromwell Gorge |work=[[New Zealand Herald]] |url=https://www.nzherald.co.nz/nz/choppers-sent-in-as-massive-landslip-closes-road-in-cromwell-gorge/DRZVUTIWUVS23VGMXXLUWHGPJY/ |access-date=20 August 2023}}</ref> With the establishment of a safe bench to work from, [[excavator]]s and an [[abseiling]] team cleared the remaining loose material over the following days.<ref>{{Cite news |date=14 August 2020 |title=Large Cromwell slip cleared |work=[[Otago Daily Times]] |url=https://www.odt.co.nz/regions/central-otago/large-cromwell-slip-cleared |access-date=20 August 2023}}</ref><ref name="New Zealand Herald"/>
===Controversy=== The Clyde Dam has rarely been without controversy since its inception. The dam has forever changed the landscape and the lives of people impacted by the filling of Lake Dunstan.
One of the Clyde Dam's most vocal critics was [[Gerald Lensen]], a geologist and the former head of Earth Deformation at the [[Department of Scientific and Industrial Research (New Zealand)|DSIR]]. Lensen had argued on numerous occasions that the Clyde Dam was unsafe, having been built on an active fault zone.<ref>{{Cite news |date=24 November 1982 |title=Hydro dams 'in fault zones' |pages=21 |work=Press |url=https://paperspast.natlib.govt.nz/newspapers/CHP19821124.2.100 |access-date=18 October 2023 |via=Papers Past}}</ref><ref>{{Cite news |date=9 April 1983 |title=Expert doubts dam's safety |pages=6 |work=Press |url=https://paperspast.natlib.govt.nz/newspapers/CHP19830409.2.43 |access-date=18 October 2023 |via=Papers Past}}</ref><ref>{{Cite news |date=19 November 1982 |title=Secrecy over dam report criticised |pages=2 |work=Press |url=https://paperspast.natlib.govt.nz/newspapers/CHP19821119.2.21 |access-date=18 October 2023 |via=Papers Past}}</ref><ref>{{cite web |title=MORNING REPORT. 1989-07-26 |url=https://www.ngataonga.org.nz/search-use-collection/search/57233/ |access-date=18 October 2023 |website=Ngā Taonga - Sound and Vision}}</ref><ref>{{cite web |title=MORNING REPORT. 1985-07-05 |url=https://www.ngataonga.org.nz/search-use-collection/search/37686/ |access-date=18 October 2023 |website=Ngā Taonga - Sound and Vision}}</ref><ref>{{cite news |date=30 March 1990 |title=Geologist doubts Clyde Dam safety |publisher=Evening Post |url=https://natlib-primo.hosted.exlibrisgroup.com/primo-explore/fulldisplay?docid=INNZ7116794970002837&context=L&vid=NLNZ&lang=en_US&tab=innz |access-date=18 October 2023}}</ref>
The National Party's ''Think Big'' economic policy was heavily criticised and debated during the early stages of the dam construction'',''<ref>{{Cite news |last=Mein |first=Geoff |date=3 January 1983 |title=More hot air than energy |pages=15 |work=Press |url=https://paperspast.natlib.govt.nz/newspapers/CHP19830103.2.145.23 |access-date=18 October 2023 |via=Papers Past}}</ref><ref>{{Cite news | date=29 July 1982 |title=Clyde dam |pages=16 |work=Press |url=https://paperspast.natlib.govt.nz/newspapers/CHP19820729.2.80.6 |access-date=18 October 2023 |via=Papers Past}}</ref> and the dam was protested extensively by all those affected by it.<ref>{{Cite news |date=13 December 1977 |title=Clutha protesters camp at dam site |pages=6 |work=Press |url=https://paperspast.natlib.govt.nz/newspapers/CHP19771213.2.43 |access-date=18 October 2023 |via=Papers Past}}</ref><ref>{{Cite news |date=13 May 1978 |title=Youths' Clyde dam protest costs $50 |pages=6 |work=Press |url=https://paperspast.natlib.govt.nz/newspapers/CHP19780513.2.48 |access-date=18 October 2023 |via=Papers Past}}</ref><ref>{{Cite news |date=4 November 1981 |title=Dam workers hit cars |pages=1 |work=Press |url=https://paperspast.natlib.govt.nz/newspapers/CHP19811104.2.6 |access-date=18 October 2023 |via=Papers Past}}</ref><ref>{{Cite news |date=8 June 1974 |title=Clutha group to fight |volume=114 |pages=2 |work=Press |issue=33555 |url=https://paperspast.natlib.govt.nz/newspapers/CHP19740608.2.19 |access-date=22 October 2023 |via=Papers Past}}</ref> Workers unions during the construction of the dam held many strikes.<ref>{{Cite news |last=Perkinson |first=Glen |date=21 June 1988 |title=Fear as dam strike cracks |pages=1 |work=Press |url=https://paperspast.natlib.govt.nz/newspapers/CHP19880621.2.2 |access-date=18 October 2023 |via=Papers Past}}</ref><ref>{{Cite news |date=23 June 1987 |title=Staff strike over Luggate decision |pages=6 |work=Press |url=https://paperspast.natlib.govt.nz/newspapers/CHP19870623.2.33 |access-date=18 October 2023 |via=Papers Past}}</ref><ref>{{Cite news |date=14 September 1984 |title=Clyde dam workers on strike |pages=6 |work=Press |url=https://paperspast.natlib.govt.nz/newspapers/CHP19840914.2.57 |access-date=18 October 2023 |via=Papers Past}}</ref><ref>{{Cite news |date=13 September 1984 |title=Clyde workers strike after hearing fails |pages=6 |work=Press |url=https://paperspast.natlib.govt.nz/newspapers/CHP19840913.2.44 |access-date=18 October 2023 |via=Papers Past}}</ref>
As the landslide stabilisation of the Cairnmuir Slide neared completion, a protest slogan was painted on the lower portion of the drainage apron which read ''Hands Off Beaumont'' referring to the potential of a further dam being built near [[Beaumont, New Zealand|Beaumont]], downstream on the Clutha River. The remnants of this graffiti are still visible.
Wider impacts with the filling of Lake Dustan have continued to impact communities with the spread of [[lagarosiphon]] (lake weed),<ref>{{Cite news |last=Huffadine |first=L. |date=19 March 2015 |title=Lake Dunstan weed 'out of control' |work=[[Otago Daily Times]] |url=https://www.odt.co.nz/regions/central-otago/lake-dunstan-weed-out-control |access-date=22 October 2023}}</ref><ref>{{Cite web |title=Lagarosiphon |url=https://www.lakedunstan.org/lagarosiphon.html |access-date=22 October 2023 |website=Lake Dunstan Charitable Trust}}</ref> and the continued sedimentation and silting-up of the Kawerau Arm of Lake Dunstan.<ref>{{Cite web |date=24 August 2022 |title=Impact of Contact Energy's Clyde Dam on Kawarau Arm of Lake Dunstan to be reviewed |url=https://www.rnz.co.nz/news/national/473415/impact-of-contact-energy-s-clyde-dam-on-kawarau-arm-of-lake-dunstan-to-be-reviewed |access-date=18 October 2023 |website=[[Radio New Zealand]] }}</ref><ref>{{Cite web |title=Silt/Sediment |url=https://www.lakedunstan.org/siltsediment.html |access-date=18 October 2023 |website=Lake Dunstan Charitable Trust}}</ref><ref>{{Cite web |last=Mckenzie-Mclean |first=Jo |date=19 September 2020 |title=Contact Energy told to 'clean up its mess' after lake turns to swamp |url=https://i.stuff.co.nz/environment/122768217/contact-energy-told-to-clean-up-its-mess-after-lake-turns-to-swamp |access-date=18 October 2023 |website=[[Stuff (website)|Stuff]] }}</ref>
== Access == [[File:State_Highway_8_realignment_work_underway_near_Gibraltar_Rock_in_the_Cromwell_Gorge.jpg|thumb|300 px|State Highway 8 realignment work underway near Gibraltar Rock in the Cromwell Gorge]] The Cromwell Gorge is accessed primarily by two routes. On the true left bank of Lake Dunstan runs State Highway 8, a single carriageway linking Clyde to Cromwell via [[Deadman's Point Bridge]]. On the true right bank of Lake Dunstan is the [[Dunstan Cycle Trail]], a purpose built cycle path which extends the existing [[Otago Central Rail Trail]].
Lake Dunstan itself is navigable from the Clyde Dam through the gorge to Cromwell and beyond.
=== State Highway 8 === Lake Dunstan floods the site of the old [[State Highway 8 (New Zealand)|State Highway 8]] (SH8) and former rail line from Clyde to Cromwell. Rail services to Cromwell had ceased by 1980 and therefore a new line to Cromwell was not required ahead of Lake Dunstan being filled. The realignment of SH8 was necessary and was constructed above the shore line of the true left of the gorge (above the former SH8 on the floor of the gorge).
====Road realignment==== The Clyde power project roading construction took a total of ten years and involved {{Convert|50|km|mi|abbr=on}} of roading and several bridges and culverts. Twenty major contracts were involved and at least {{Convert|20|e6m3|e6cuft|abbr=on}} of rock and gravel moved.<ref name="CluthaPower" /> New bridges were constructed at Cromwell ([[Deadman's Point Bridge]]), [[Bannockburn, New Zealand|Bannockburn]] and [[Lowburn]]. New road sections were required on both sides of Lake Dunstan out of Cromwell to the north:
* {{Convert|4|km|mi|abbr=on}} were realigned from Cromwell to Lowburn, and a further 4 km after Lowburn toward [[Wānaka]] * {{Convert|13|km|mi|abbr=on}} were realigned between Cromwell and [[Tarras]] on the true left of Lake Dunstan * {{Convert|22|km|mi|abbr=on}} were realigned through the Cromwell Gorge {{Ndash}} the most challenging road section due to the stabilisation required for numerous slips
The final section of road through the Cromwell Gorge was opened in 1988.<ref name="CluthaPower" />
The realignment of SH8 directly affected twenty nine sites of archaeological significance.<ref name="Newman1977">{{cite web |last1=Newman |first1=M. |title=Archaeological and Historic Sites Affected by Realignment of State Highway 8, Cromwell to Clyde |url=https://dl.heritage.org.nz/greenstone3-foo/library/sites/hnz/collect/pdf-reports/index/assoc/Newman5.dir/Newman5.pdf |website=Archaeological Reports Digital Library, Heritage New Zealand Pouhere Taonga |publisher=New Zealand Historic Places Trust |access-date=30 September 2023 |location=Wellington, NZ |date=1977}}</ref> The majority of the sites were associated with heritage gold mining activities (stone walled buildings, stone walls, dams, water races, stone stacks), although six sites were pre-historic rock shelters.<ref name="Newman1977" />
Moa finds continued during roadworks; the remains of at least five moas were successfully recovered when a wary bulldozer operator noticed moa bone fragments at the top of his blade while realigning the road section above the old Cromwell Railway site.<ref>{{Cite news |date=2 February 1981 |title=Driver's moa find |pages=23 |work=Press |url=https://paperspast.natlib.govt.nz/newspapers/CHP19810202.2.143 |access-date=21 October 2023}}</ref>
=== Lake Dunstan Trail === [[File:Dunstan Cycle Trail.jpg|thumb|300 px|Cantilevered boardwalk section of the Dunstan Cycle Trail through the Cromwell Gorge. The boardwalk is attached to rock bluffs of the Cairnmuir Mountains which plunge into Lake Dunstan.]] In May 2021 the Lake Dustan Trail was opened through the Cromwell Gorge.<ref>{{Cite web |title=Lake Dunstan Trail Grand Opening |url=https://centralotagonz.com/tracks-and-trails/lake-dunstan-trail/lake-dunstan-trail-grand-opening |access-date=22 October 2023 |website=Central Otago District Council}}</ref> Although it does not form part of the existing Otago Central Rail Trail, it is a purpose-built extension on the opposite true right side of the gorge, running along the foot of the Cairnmuir Mountains. The Lake Dustan Trail links Clyde and Cromwell, offering cyclists and walkers a Grade 2{{Ndash}}3 (easy{{Ndash}}intermediate) route across bridges, switchbacks, cantilevered boardwalks pinned to sheer bluffs suspended above Lake Dunstan, or the gentle rolling vineyards of [[Bannockburn, New Zealand|Bannockburn]].
The trail through the gorge from Clyde to Cromwell's Historical Precinct is {{Convert|41.2|km|mi|abbr=on}}, although the trail currently extends a further {{Convert|16.4|km|mi|abbr=on}} north of Cromwell along the western shore of Lake Dunstan.<ref>{{Cite web |title=Preparing to Ride the Lake Dunstan Trail |url=https://centralotagonz.com/tracks-and-trails/lake-dunstan-trail/trail-safety/ |access-date=22 October 2023 |website=Central Otago District Council}}</ref>
=== Gorge guardian sculpture === [[File:Clyde Kārearea Sculpture.jpg|thumb|300 px|Kārearea (New Zealand Falcon) sculpture above Clyde Dam by artist Dan Kelly]] On 21 October 2023 the Historic Clyde Incorporated Charitable Society unveiled a steel sculpture of a [[New Zealand falcon|Kārearea]] (New Zealand falcon), erected overlooking the Clyde dam at the entrance to the gorge.<ref>{{Cite web |last=Robb |first=A. |date=17 October 2023 |title=New sculpture for entrance to Clyde |url=https://centralapp.nz/news/news/new-sculpture-for-entrance-to-clyde |access-date=22 October 2023 |website=The Central App}}</ref><ref>{{Cite web |title=Project Karearea |url=http://www.historicclyde.co.nz/art-promotions/project-karearea/ |access-date=22 October 2023 |website=Historic Clyde, Central Otago}}</ref> The {{Convert|5|m|ft|abbr=on}} sculpture by artist Dan Kelly is fashioned from recycled steel, and will stand as guardian to the gorge and the township of Clyde below.
==See also== *[[Kawarau Gorge]] *[[Otago Central Rail Trail]] *[[Lake Dunstan]]
==Further reading==
* Cowan W. J. 2018. ''Rails to Cromwell : The Otago Central Railway in Stories and Pictures''. Dunedin New Zealand: Molyneux Press Limited. * Cunningham, G. (2008). Guide to the Otago Goldfields Heritage Trail. New Zealand: Penguin Group New Zealand, Limited. * Ng, J. (1993). Windows on a Chinese Past: How the Cantonese goldseekers and their heirs settled in New Zealand. New Zealand: Otago Heritage Books. * Temple P. 1985. ''New Zealand Explorers : Great Journeys of Discovery''. Christchurch N.Z: Whitcoulls. * Veitch, B. (1976). Clyde on the Dunstan. New Zealand: J. McIndoe.
==Notes== {{note|Dagger|†}} Despite a lack of recent movement near the Clyde Dam, the recurrence interval for the Dunstan Fault is estimated to be ~7000 years<ref name="Barrell" />
== External links ==
* [https://handsoffbeaumont.blogspot.com/ Hands Off Beaumont] * [https://centralotagonz.com/tracks-and-trails/lake-dunstan-trail/ Lake Dunstan Trail] * [https://mightyclutha.blogspot.com/ Mighty Clutha - Otago's Stolen Treasure] * [https://www.otagocentralrailtrail.co.nz/ Otago Central Rail Trail]
==References== {{Reflist}}
{{Clutha}} {{Coord|45|06|S|169|17|E|type:city|display=title}}
[[Category:Canyons and gorges of Otago]] [[Category:Clutha River]] [[Category:Cromwell, New Zealand]]