Lake Karapiro is an artificial reservoir lake on the Waikato River, 30 kilometres (19 mi) south-east of the city of Hamilton in New Zealand's North Island. The lake was formed in 1947 by damming the Waikato River to store water for the 96-megawatt Karapiro hydroelectric power station.
|Primary inflows||Waikato River|
|Primary outflows||Waikato River|
|Basin countries||New Zealand|
|Max. length||11.0 kilometres (6.8 mi)|
|Max. width||0.9 kilometres (0.56 mi)|
|Surface area||7.7 km2 (3.0 sq mi)|
|Average depth||11.0 metres (36.1 ft)|
|Max. depth||30.5 metres (100 ft)|
|Water volume||8.5 cubic kilometres (2.0 cu mi)|
|Surface elevation||50.5–53.5 metres (166–176 ft)|
'Kara' means stone (dark basalt), 'piro' means evil-smelling. According to legend, Karapiro was the stronghold of the chief O-Te-Ihingarangi, and was where the Ngati Haua and their Tauranga allies made a defensive pact during the New Zealand Wars of 1864.
The lake, regarded as one of New Zealand's best rowing venues, hosted the World Rowing Championships in 1978 and 2010, as well as the rowing events for the 1950 British Empire Games. 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). Rowers who train on the lake mostly live in nearby 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.
The 96-megawatt Karapiro Power Station is located adjacent to the dam at the head of the lake, and is the eighth and last hydroelectric power station located on the Waikato River. Water for the power station up to 362 cubic metres per second (12,800 cu ft/s) at full power, is taken from the lake and passed through three Kaplan turbines in the powerhouse, before being deposited into the lower Waikato River. Each turbine turns a 32 MW generator, and the electricity from the generators is fed into Transpower's national transmission grid. The station is a base load generator due to its need to maintain water flows into the Waikato River system beyond the lake.
The ten-megawatt Horahora Power Station at Horahora, 13 km upstream of Karapiro Dam, part of an earlier hydroelectric power scheme, was flooded with the formation of Lake Karapiro.
- "Lake Levels". Mighty River Power.
- Lowe, D.J., Green, J.D. (1987). Viner, A.B. (ed.). Inland waters of New Zealand. Wellington: DSIR Science Information Publishing Centre. pp. 471–474. ISBN 0-477-06799-9.CS1 maint: multiple names: authors list (link)
- "Karapiro - History". Mighty River Power. Archived from the original on 10 June 2011.
- "NZ to host 2010 world rowing champs". The New Zealand Herald. NZPA. 8 June 2006. Retrieved 13 October 2011.
- Martin, John E. (1991). People, politics and power stations : electric power generation in New Zealand, 1880–1990. ISBN 0-908912-16-1.