View source for Lake Karapiro

{{Use dmy dates|date=July 2019}}
{{Use New Zealand English|date=July 2019}}
{{Infobox lake
| name               = Lake Karapiro
| image              = Lake Karapiro - December 2020.jpg
| alt = Lake Karapiro
| caption            = Lake Karapiro
| image_bathymetry   = 
| caption_bathymetry = 
| location           = [[North Island]]
| coords             = {{coord|37.92856|S|175.544529|E|region:NZ-WKO_type:waterbody|display=inline,title}}
| lake_type          = [[reservoir]]
| inflow             = [[Waikato River]]
| pushpin_map        = North Island
| pushpin_map_alt = Location of Lake Karapiro
| outflow            = [[Waikato River]]
| catchment          = 
| basin_countries    = New Zealand
| length             = {{convert|11.0|km}}
| width              = {{convert|0.9|km}}
| area               = {{convert|7.7|km2|abbr=on}}
| depth              = {{convert|11.0|m}}
| max-depth          = {{convert|30.5|m}}
| volume             = {{convert|0.085|km3}}
| residence_time     = 
| shore              = 
| elevation          = {{convert|50.5|-|53.5|m}} <ref>{{cite web| url=http://www.mightyriver.co.nz/Our-Business/Generation/Lake-Levels.aspx| title=Lake Levels| publisher=Mighty River Power}}</ref>
| islands            = 
| cities             = 
| frozen             = 
| date-flooded       = {{Start date|1947|04}}
}}
[[File:Aerial View of Karapiro Hydro Power Station.jpg|thumb|Karapiro Dam and Lake Karapiro in February 1969.]]
'''Lake Karapiro''' ({{langx|mi|Karāpiro}}) is an artificial [[reservoir]] lake on the [[Waikato River]] at [[Karapiro]], {{convert|8|km}} south-east of [[Cambridge, New Zealand|Cambridge]] in New Zealand's [[North Island]]. The lake was formed in 1947 by the damming of the Waikato River to store water for the 96-megawatt [[Karapiro Power Station|Karapiro power station]].<ref name="lowe">{{cite book| editor = Viner, A.B.| author=Lowe, D.J., Green, J.D.| title=Inland waters of New Zealand| pages=471–474| publisher=DSIR Science Information Publishing Centre| location=Wellington| year=1987| isbn=0-477-06799-9}}</ref> The lake is also one of two premier [[Rowing (sport)|rowing]] venues in New Zealand (alongside [[Lake Ruataniwha]] in Canterbury) and is the base for the country's [[High performance sport|high-performance]] rowing programme.

== History and etymology ==
In about 1600, Te Ihingarangi built a [[pā]] (fortified village) called Te Tiki o Ihingarangi near where Lake Karapiro is today.<ref>{{cite web |url= https://cambridgemuseum.org.nz/archaeology-2/ |title=Archaeology |work=Cambridge Museum |date=8 June 2017 |publisher=Cambridge Historical Society |access-date=6 February 2021}}</ref>

In 1830, [[Ngāti Hauā]] defeated [[Ngāti Maru (Hauraki)|Ngāti Maru]] in a battle at Taumatawīwī, two kilometres south of Karapiro Domain. On the orders of the Ngāti Hauā chief [[Te Waharoa]], his dead warriors were cremated, this taking place on rocks beside the Waikato River, the location then becoming known as ''Karāpiro'', from the [[Māori language]] words {{lang|mi|karā}}, meaning "basaltic stone", and {{lang|mi|piro}}, meaning "foul smelling". The site was flooded when the lake created.<ref name=NZHist>{{cite web |url= https://nzhistory.govt.nz/media/video/lake-karapiro-roadside-stories |title=Lake Karapiro – roadside stories |date=2011 |work=NZHistory |publisher=Ministry for Culture and Heritage |access-date=6 February 2021}}</ref><ref>{{cite news |title=Our Truth, Tā Mātou Pono: The desecration at Lake Karāpiro |first=Lawrence |last=Gullery |date=6 February 2021 |url= https://www.stuff.co.nz/pou-tiaki/our-truth/124026945/our-truth-t-mtou-pono-the-desecration-at-lake-karpiro |newspaper=[[Stuff (website)|Stuff]] |access-date=7 February 2021}}</ref> The ten-megawatt [[Horahora Power Station]], 13&nbsp;km upstream of Karapiro Dam was also flooded with the formation of Lake Karapiro.<ref>{{cite book|last=Martin|first=John E. |title= People, politics and power stations : electric power generation in New Zealand, 1880–1990|year=1991|publisher=Bridget Williams Books |isbn=0-908912-16-1}}</ref>

Construction of the Karapiro Dam began in 1940, however progress was slow due to labour and material shortages related to World War II. The dam was completed in early 1947, four years behind schedule. Due to the post-war electricity shortages, the filling of Lake Karapiro had to be coordinated to minimise the time between Horahora's decommissioning and Karapiro's commissioning. The lake level reached Horahora on 4 April 1947 upon which Horahora stopped generating and was submerged. The lake was sufficiently filled on 10 April 1947 to allow the first turbine-generator at Karapiro to enter service.<ref name=":0">{{Cite journal|title=STATE HYDRO-ELECTRIC DEPARTMENT STATEMENT BY THE HON. R. SEMPLE, MINISTER IN CHARGE OF THE STATE HYDRO-ELECTRIC DEPARTMENT|url=https://atojs.natlib.govt.nz/cgi-bin/atojs?a=d&cl=search&d=AJHR1948-I.2.3.3.3&srpos=15&e=-------10--11---bySH---0-AJHR%5f1948%5fI%5fCZz-G-|journal=Appendix to the Journals of the House of Representatives|volume=1948 session I|pages=D-04}}</ref>

== Rowing venue ==
[[File:Sir Don Rowlands Centre - Lake Karapiro.jpg|thumb|none|Sir Don Rowlands Centre]]
[[File:Hannah Osborne 2018 Christmas Regatta.jpg|thumb|none|[[Hannah Osborne]] at the 2018 Christmas Regatta]]
The lake, regarded as one of New Zealand's best [[Rowing (sport)|rowing]] venues, hosted the [[World Rowing Championships]] in [[1978 World Rowing Championships|1978]] and [[2010 World Rowing Championships|2010]], as well as the rowing events for the [[1950 British Empire Games]].<ref>{{cite web |title=Rowing in New Zealand |url= https://nzhistory.govt.nz/culture/rowing-in-new-zealand |publisher=[[Ministry for Culture and Heritage]] |access-date=4 July 2021 |date=5 January 2016}}</ref> The national rowing championships, then called the Dominion championships, were first held on the lake in 1949. Since the 1980s, Lake Karapiro alternates with the South Island's [[Lake Ruataniwha]] in hosting the New Zealand national rowing championships and the New Zealand secondary school rowing championships ([[Maadi Cup]]).<ref>{{cite web |title=The world comes to Karapiro |url= https://nzhistory.govt.nz/culture/rowing-in-new-zealand/world-comes-to-karapiro |publisher=[[Ministry for Culture and Heritage]] |access-date=4 July 2021 |date=5 January 2016}}</ref> Rowers who train on the lake mostly live in nearby [[Cambridge, New Zealand|Cambridge]].

An [[International Rowing Federation]] inspection panel visited Lake Karapiro in March 2006 and said in its report that it was one of the fairest courses in the world they had seen and that the lake was one of the most picturesque in the world.<ref name="NZ_Herald_10385584">{{cite news |url=http://www.nzherald.co.nz/section/story.cfm?c_id=4&objectid=10385584 |title=NZ to host 2010 world rowing champs |date=8 June 2006 |agency=[[NZPA]] |work=[[The New Zealand Herald]] |access-date=13 October 2011}}</ref>

The lake hosted the 2010 Rowing World Championships.<ref name="2010 World Rowing Championships">{{cite news |url= http://www.worldrowing.com/events/2010-world-championships |title=2010 World Rowing Championships |date= 7 November 2010 |work=[[World Rowing]] |access-date=14 December 2020}}</ref> The purpose-built Sir [[Don Rowlands]] Centre was completed in June 2010, prior to the event.<ref name="Lake Karapiro: Opening of Don Rowlands Centre">{{cite news |url=https://gg.govt.nz/publications/lake-karapiro-official-opening-don-rowlands-centre |title=Lake Karapiro: Official Opening of the Don Rowlands Centre |date=1 June 2010 |work=[[Governor-General of New Zealand]] |access-date=14 December 2020}}</ref>

==Hydroelectric power==
The 96-megawatt [[Karapiro Power Station]] is located adjacent to the dam at the northern end of the lake, and is the eighth and last hydroelectric power station located on the Waikato River. Water taken from the lake is passed through three [[Kaplan turbine|Kaplan turbines]] in the powerhouse, before being deposited into the lower Waikato River. Each turbine turns a 32&nbsp;MW generator, and the electricity from the generators is fed into [[Transpower New Zealand Limited|Transpower]]'s [[National Grid (New Zealand)|national grid]]. The station is a [[base load power plant|base load generator]] due to its need to maintain water flows into the Waikato River system beyond the lake.

{{Wide image|Lake Karapiro Panorama - Dec 2020.jpg|1280px|Lake Karapiro from the Sir Don Rowlands Centre}}

==Invasive species==
Lake Karapiro is infested with hornwort, a submerged macrophyte from North America that is ranked as the worst submerged macrophyte in New Zealand.<ref>{{cite web |url=https://www.doc.govt.nz/nature/pests-and-threats/weeds/common-weeds/hornwort/ |title=Hornwort |website=Hornwort |publisher=DOC |access-date=11 January 2024}}</ref> This plant is an unwanted organism under the [[Biosecurity Act 1993]]. 

More recently, the lake was the first site where [[Corbicula fluminea|gold clams]] were detected in New Zealand, in May 2023. The gold clam grows and breeds very quickly, and can alter an ecosystem by reducing the majority of the phytoplankton, excreting a lot of nitrogen and phosphorus, and physically dominating the available space on the river or lakebed. Despite this, the lake is still open for recreation,<ref>{{cite web |url=https://www.lakekarapiro.co.nz/ |title=Lake Karapiro |website=Lake Karapiro |access-date=11 January 2024}}</ref> making it a threat to other waterways because people may unknowingly spread golden clams on their watercraft. It has been added to the unwanted organism register.

==Climate==

{{Weather box|width=auto
|metric first=y
|single line=y 
|collapsed = Y
|location = Lake Karapiro (1991–2020)
|Jan high C = 	24.4
|Feb high C = 	24.8
|Mar high C = 	23.0
|Apr high C = 	19.9
|May high C = 	16.9
|Jun high C = 	14.3
|Jul high C = 	13.5
|Aug high C = 	14.6
|Sep high C = 	16.0
|Oct high C = 	18.0
|Nov high C = 	20.0
|Dec high C = 	22.5
| year high C = 	
|Jan mean C = 	19.4
|Feb mean C = 	20.0
|Mar mean C = 	18.2
|Apr mean C = 	15.5
|May mean C = 	12.8
|Jun mean C = 	10.4
|Jul mean C = 	9.6
|Aug mean C = 	10.6
|Sep mean C = 	12.0
|Oct mean C = 	13.8
|Nov mean C = 	15.5
|Dec mean C = 	18.0
| year mean C = 	
|Jan low C = 	14.5
|Feb low C = 	15.1
|Mar low C = 	13.4
|Apr low C = 	11.0
|May low C = 	8.8
|Jun low C = 	6.6
|Jul low C = 	5.7
|Aug low C = 	6.5
|Sep low C = 	8.0
|Oct low C = 	9.6
|Nov low C = 	11.0
|Dec low C = 	13.6
| year low C = 	
|rain colour = green	
|Jan rain mm = 	77.4
|Feb rain mm = 	66.2
|Mar rain mm = 	66.6
|Apr rain mm = 	97.5
|May rain mm = 	100.4
|Jun rain mm = 	113.5
|Jul rain mm = 	124.0
|Aug rain mm = 	113.9
|Sep rain mm = 	99.5
|Oct rain mm = 	85.1
|Nov rain mm = 	79.2
|Dec rain mm = 	95.2
|year rain mm = 	
|source 1 = NIWA<ref name= NIWA>
{{cite web
|url = http://cliflo.niwa.co.nz
|title = CliFlo – National Climate Database : Lake Karapiro Cws
|publisher = NIWA
|access-date = 20 May 2024}}</ref>
}}

== References ==
{{Reflist}}

== External links ==
{{commons category|Lake Karapiro}}
* {{cite web| url=https://www.mercury.co.nz/Our-Business/Generation/Our-Power-Stations.aspx| title=Our Power Stations| publisher=Mercury}}

{{Rowing World Championship Venues}}
{{Waikato}}

{{DEFAULTSORT:Karapiro, Lake}}
[[Category:Reservoirs in New Zealand]]
[[Category:Lakes of Waikato]]
[[Category:Waikato River]]
[[Category:Rowing venues]]