Arapuni Power Station
Encyclopedia
Arapuni Power Station is a hydroelectric power station on the Waikato River
, in the North Island of New Zealand. It is the seventh and penultimate hydroelectric power station on the Waikato River. It is also the oldest currently generating, the first government-built, and the largest single hydroelectric power station on the Waikato River.
Arapuni, due to its proximity to Hamilton
, plays an important part in voltage support and frequency keeping in the city and the wider Waikato River. Even though it is 80 years old, continuous improvement and refurbishment of the station's generation equipment ensures Arapuni remains efficient.
The powerhouse and dam at Arapuni are under protection of the Historic Places Trust
, becoming Category I Historic Places in November 1987 and August 1991 respectively. It is one of the few generating power stations in New Zealand to be listed on the register.
Arapuni is operated by state-owned electricity generator Mighty River Power.
that was decommissioned in 1947 on the filling of Lake Karapiro
.
Initial surveying of the site began in 1916, but in 1920, the surveying was halted due to lack of government funds to progress the project. Construction of Arapuni finally began in 1924, but repeated heavy rain and the resulting floods dogged the early works. The station, complete with three turbines and provisions for a fourth, was commissioned in mid-1929. Shortly after commissioning, Arapuni was closed for two years while a water seepage problem was investigated and the headrace lined. The station, with the addition of a fourth turbine, was recommissioned in May 1932.
The Arapuni Suspension Bridge
, just downstream from the power station, was opened in 1926. It gave access from 'top camp' (which eventually became the Arapuni
township) on the true right to the power station construction site on the true left of the Waikato River.
In 1934, increasing demand for electricity resulted in Arapuni being extended. The powerhouse was doubled in size, and provisions for four more turbines were made. Turbines 5 and 6 were commissioned four years later in 1938. The last two turbines were commissioned in 1946 to meet the increasing demand for electricity following World War II
.
In 1990, a $50 million repair, refurbishment and upgrade project was completed, the first stage of which involved construction of a diversion channel. In 2000 it was determined that the historic seepage problem had worsened, interim repairs were carried out while a more permanent solution was devised and this took the form of a $20 million engineering project, which was carried out in 2005-07. In 2001, work was completed on four of Arapuni's turbines to increase capacity from 24.7MW to 26.7MW each and to improve their peak efficiency.
Waikato River
The Waikato River is the longest river in New Zealand. In the North Island, it runs for 425 kilometres from the eastern slopes of Mount Ruapehu, joining the Tongariro River system and emptying into Lake Taupo, New Zealand's largest lake. It drains Taupo at the lake's northeastern edge, creates the...
, in the North Island of New Zealand. It is the seventh and penultimate hydroelectric power station on the Waikato River. It is also the oldest currently generating, the first government-built, and the largest single hydroelectric power station on the Waikato River.
Arapuni, due to its proximity to Hamilton
Hamilton, New Zealand
Hamilton is the centre of New Zealand's fourth largest urban area, and Hamilton City is the country's fourth largest territorial authority. Hamilton is in the Waikato Region of the North Island, approximately south of Auckland...
, plays an important part in voltage support and frequency keeping in the city and the wider Waikato River. Even though it is 80 years old, continuous improvement and refurbishment of the station's generation equipment ensures Arapuni remains efficient.
The powerhouse and dam at Arapuni are under protection of the Historic Places Trust
New Zealand Historic Places Trust
The New Zealand Historic Places Trust is a non-profit trust that advocates for the protection of ancestral sites and heritage buildings in New Zealand...
, becoming Category I Historic Places in November 1987 and August 1991 respectively. It is one of the few generating power stations in New Zealand to be listed on the register.
Arapuni is operated by state-owned electricity generator Mighty River Power.
History
Arapuni was the first government-built hydroelectric station on the Waikato River, and the second after the privately-owned Horahora Power StationHorahora Power Station
Horahora Power Station was an early hydroelectric power station on the Waikato River in New Zealand. It was the country’s first large-scale power station, completed in 1913. Initially built to service a gold mine, the power station was expanded to supply a significant part of the North Island...
that was decommissioned in 1947 on the filling of Lake Karapiro
Lake Karapiro
Lake Karapiro is an artificial reservoir lake on the Waikato River in the North Island of New Zealand. The lake, near Cambridge and some south-east of the city of Hamilton, was created in 1947 to store water for the Karapiro Power Station, the last of the eight hydroelectric power stations on the...
.
Initial surveying of the site began in 1916, but in 1920, the surveying was halted due to lack of government funds to progress the project. Construction of Arapuni finally began in 1924, but repeated heavy rain and the resulting floods dogged the early works. The station, complete with three turbines and provisions for a fourth, was commissioned in mid-1929. Shortly after commissioning, Arapuni was closed for two years while a water seepage problem was investigated and the headrace lined. The station, with the addition of a fourth turbine, was recommissioned in May 1932.
The Arapuni Suspension Bridge
Arapuni Suspension Bridge
The Arapuni Suspension Bridge is located just downstream from the Arapuni Power Station on the Waikato River in the South Waikato District of New Zealand...
, just downstream from the power station, was opened in 1926. It gave access from 'top camp' (which eventually became the Arapuni
Arapuni
Arapuni is a rural town centre on the Waikato river in the South Waikato District of New Zealand. The population on census night 2006 was 2,145 usual residents, slightly down from 2,163 in 2001 and 2,211 in 1996. The town sits next to a hydroelectric dam at Lake Arapuni, one of six in the South...
township) on the true right to the power station construction site on the true left of the Waikato River.
In 1934, increasing demand for electricity resulted in Arapuni being extended. The powerhouse was doubled in size, and provisions for four more turbines were made. Turbines 5 and 6 were commissioned four years later in 1938. The last two turbines were commissioned in 1946 to meet the increasing demand for electricity following World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
.
In 1990, a $50 million repair, refurbishment and upgrade project was completed, the first stage of which involved construction of a diversion channel. In 2000 it was determined that the historic seepage problem had worsened, interim repairs were carried out while a more permanent solution was devised and this took the form of a $20 million engineering project, which was carried out in 2005-07. In 2001, work was completed on four of Arapuni's turbines to increase capacity from 24.7MW to 26.7MW each and to improve their peak efficiency.