![Manapour iPower Station Model](https://upload.wikimedia.org/wikipedia/commons/c/c1/Manapour_iPower_Station_Model.jpg)
Manapōuri Power Station is an
underground
Underground most commonly refers to:
* Subterranea (geography), the regions beneath the surface of the Earth
Underground may also refer to:
Places
* The Underground (Boston), a music club in the Allston neighborhood of Boston
* The Underground ...
hydroelectric
Hydroelectricity, or hydroelectric power, is electricity generated from hydropower (water power). Hydropower supplies one sixth of the world's electricity, almost 4500 TWh in 2020, which is more than all other renewable sources combined and ...
power station on the western arm of
Lake Manapouri
Lake Manapouri is located in the South Island of New Zealand. The lake is situated within the Fiordland National Park and the wider region of Te Wahipounamu South West New Zealand World Heritage Area.
Māori History
According to Māori people, ...
in
Fiordland National Park
Fiordland National Park occupies the southwest corner of the South Island of New Zealand. It is by far the largest of the 13 national parks in New Zealand, with an area of , and a major part of the Te Wahipounamu World Heritage Site. The park i ...
, in the
South Island
The South Island, also officially named , is the larger of the two major islands of New Zealand in surface area, the other being the smaller but more populous North Island. It is bordered to the north by Cook Strait, to the west by the Tasman ...
of
New Zealand
New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...
. At 854 MW installed capacity (although limited to 800 MW due to
resource consent
A resource consent is the authorisation given to certain activities or uses of natural and physical resources required under the New Zealand Resource Management Act (the "RMA"). Some activities may either be specifically authorised by the RMA or ...
limits
), it is the largest hydroelectric power station in New Zealand, and the second largest power station in New Zealand. The station is noted for the controversy and environmental protests by the
Save Manapouri Campaign
The Save Manapouri campaign was an environmental campaign waged between 1969 and 1972 in New Zealand to prevent the raising of the levels of lakes Manapouri and Te Anau as part of the construction of the Manapouri Power Project.
Origins
The ...
against raising the level of Lake Manapouri to increase the station's
hydraulic head, which galvanised New Zealanders and were one of the foundations of the New Zealand
environmental movement
The environmental movement (sometimes referred to as the ecology movement), also including conservation and green politics, is a diverse philosophical, social, and political movement for addressing environmental issues. Environmentalists a ...
.
Completed in 1971, Manapōuri was built primarily to supply electricity for the
Tiwai Point aluminium smelter
The Tiwai Point Aluminium Smelter is an aluminium smelter owned by Rio Tinto Group (79.36%) and the Sumitomo Group (20.64%), via a joint venture called New Zealand Aluminium Smelters (NZAS) Limited.
The facility, New Zealand's only aluminium sm ...
near
Bluff
Bluff or The Bluff may refer to:
Places Australia
* Bluff, Queensland, Australia, a town
* The Bluff, Queensland (Ipswich), a rural locality in the city of Ipswich
* The Bluff, Queensland (Toowoomba Region), a rural locality
* Bluff River (New ...
, some to the southeast. The station utilises the drop between the western arm of Lake Manapouri and the
Deep Cove branch of the
Doubtful Sound
Doubtful Sound / Patea is a fiord in Fiordland, in the far south west of New Zealand. It is located in the same region as the smaller but more famous and accessible Milford Sound / Piopiotahi. It took second place after Milford Sound as New Zea ...
away to generate electricity. The construction of the station required the excavation of almost 1.4 million tonnes of hard rock to build the machine hall and a 10 km tailrace tunnel, with a second parallel tailrace tunnel completed in 2002 to increase the station's capacity.
Since April 1999, the power station has been owned and operated by
state-owned electricity generator
Meridian Energy
Meridian Energy Limited is a New Zealand electricity generator and retailer. The company generates the largest proportion of New Zealand's electricity, generating 35 percent of the country's electricity in the year ending December 2014, and is ...
.
Construction
The power station machine hall was excavated from solid granite rock 200 metres below the level of Lake Manapōuri. Two tailrace tunnels take the water that passes through the power station to
Deep Cove, a branch of
Doubtful Sound
Doubtful Sound / Patea is a fiord in Fiordland, in the far south west of New Zealand. It is located in the same region as the smaller but more famous and accessible Milford Sound / Piopiotahi. It took second place after Milford Sound as New Zea ...
, away.
Access to the power station is via a two-kilometre vehicle-access tunnel which spirals down from the surface, or a
lift
Lift or LIFT may refer to:
Physical devices
* Elevator, or lift, a device used for raising and lowering people or goods
** Paternoster lift, a type of lift using a continuous chain of cars which do not stop
** Patient lift, or Hoyer lift, mobil ...
that drops down from the control room above the lake. There is no road access into the site; a regular boat service ferries power station workers in 35 km across the lake from
Pearl Harbour
Pearl Harbor is an American lagoon harbor on the island of Oahu, Hawaii, west of Honolulu. It was often visited by the Naval fleet of the United States, before it was acquired from the Hawaiian Kingdom by the U.S. with the signing of the Re ...
, located in the town of
Manapouri
Manapouri is a small town in Southland / Fiordland, in the southwest corner of the South Island, in New Zealand. The township is the westernmost municipality in New Zealand. Located at the edge of the Fiordland National Park, on the eastern ...
at the southeast corner of the lake.
This same access was for many years used to ferry tourists for public tours of the site, but since 2018 maintenance work by Meridian Energy means tours are closed "for an indefinite period".
The original construction of the power station cost
NZ$
The New Zealand dollar ( mi, tāra o Aotearoa; sign: $, NZ$; code: NZD) is the official currency and legal tender of New Zealand, the Cook Islands, Niue, the Ross Dependency, Tokelau, and a British territory, the Pitcairn Islands. Within New ...
135.5 million (NZ$2.15 billion in 2013 dollars), involved almost 8 million man hours to construct, and claimed the lives of 16 workers.
Soon after the power station began generating at full capacity in 1972, engineers confirmed a design problem. Greater than anticipated friction between the water and the tailrace tunnel walls meant reduced
hydrodynamic
In physics and engineering, fluid dynamics is a subdiscipline of fluid mechanics that describes the flow of fluids— liquids and gases. It has several subdisciplines, including '' aerodynamics'' (the study of air and other gases in motion) a ...
head. For 30 years, until 2002, station operators risked flooding the powerhouse if they ran the station at an output greater than (with high lake level and a low tide the station could generate up to ), far short of the designed peak capacity of . Construction of a second tailrace tunnel in the late 1990s, long and 10 metres in diameter, finally solved the problem and increased capacity to . The increased exit flow also increased the effective head, allowing the turbines to generate more power without using more water.
History
Early history
The first surveyors mapping out this corner of New Zealand noted the potential for hydro generation in the 178-metre drop from the lake to the
Tasman Sea
The Tasman Sea (Māori: ''Te Tai-o-Rēhua'', ) is a marginal sea of the South Pacific Ocean, situated between Australia and New Zealand. It measures about across and about from north to south. The sea was named after the Dutch explorer Abe ...
at
Doubtful Sound
Doubtful Sound / Patea is a fiord in Fiordland, in the far south west of New Zealand. It is located in the same region as the smaller but more famous and accessible Milford Sound / Piopiotahi. It took second place after Milford Sound as New Zea ...
. The idea of building a power station was first formulated by Peter Hay, the Superintending Engineer of the Public Works Department, and Lemuel Morris Hancock, the Electrical Engineer and General Superintendent of the Transmission Department of the California Gas and Electric Company during their November 1903 inspection of Lakes Manapōuri and Te Anau. Each of the 1904 reports by Hay and Hancock noted the hydraulic potential of the lake systems, being so high above sea level, and while the rugged isolation of the region meant that it would be neither practical nor economic to generate power for domestic consumption, the engineers realised that the location and scale of the project made it uniquely suited to electro-industrial developments such as electro-chemical or electro-metallurgical production.
In January 1926, a Wellington-based syndicate of ten businessmen headed by Joseph Orchiston and Arthur Leigh Hunt, ''New Zealand Sounds Hydro-Electric Concessions Limited'', was granted by the government via an Order in Council the rights to develop the waters which discharged into Deep Cove, Doubtful Sound, and the waters of Lake Manapōuri, to generate in total some . The company attempted to attract Australian, British and American finance to develop the project, which would have required the construction of a powerhouse and factory complex in Deep Cove, with accommodation for an estimated 2,000 workers and wharf facilities, with the complex producing atmospheric nitrogen in the form of fertiliser and munitions. Various attempts to finance the scheme were not successful, with the water rights lapsing and the company fading into obscurity by the 1950s.
In 1955 the modern history of Manapōuri starts, when
Harry Evans, a New Zealand geologist with
Consolidated Zinc Proprietary Ltd identified a commercial deposit of
bauxite
Bauxite is a sedimentary rock with a relatively high aluminium content. It is the world's main source of aluminium and gallium. Bauxite consists mostly of the aluminium minerals gibbsite (Al(OH)3), boehmite (γ-AlO(OH)) and diaspore (α-AlO ...
in
Australia
Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...
on the west coast of
Cape York Peninsula
Cape York Peninsula is a large peninsula located in Far North Queensland, Australia. It is the largest unspoiled wilderness in northern Australia.Mittermeier, R.E. et al. (2002). Wilderness: Earth’s last wild places. Mexico City: Agrupación ...
, near
Weipa
Weipa () is a coastal mining town in the local government area of Weipa Town in Queensland. It is the largest town on the Cape York Peninsula. It exists because of the enormous bauxite deposits along the coast. The Port of Weipa is mainly invol ...
. It turned out to be the largest deposit of bauxite in the world yet discovered. In 1956
The Commonwealth Aluminium Corporation Pty Ltd, later known as Comalco, was formed to develop the bauxite deposits. The company started investigating sources of large quantities of cheap electricity needed to
reduce
Reduction, reduced, or reduce may refer to:
Science and technology Chemistry
* Reduction (chemistry), part of a reduction-oxidation (redox) reaction in which atoms have their oxidation state changed.
** Organic redox reaction, a redox react ...
the
alumina recovered from the bauxite into aluminium. Comalco settled on Manapōuri as that source of power and
Bluff
Bluff or The Bluff may refer to:
Places Australia
* Bluff, Queensland, Australia, a town
* The Bluff, Queensland (Ipswich), a rural locality in the city of Ipswich
* The Bluff, Queensland (Toowoomba Region), a rural locality
* Bluff River (New ...
as the site of the smelter. The plan was to refine the bauxite to alumina in Queensland, ship the alumina to New Zealand for smelting into metal, then ship it away to market.
Construction history
*February 1963,
Bechtel Pacific Corporation won the design and supervision contract.
*July 1963,
Utah Construction and Mining Company and two local firms won contracts to construct the tailrace tunnel and Wilmot Pass road. Utah Construction also won the powerhouse contract.
*August 1963,
''Wanganella'', a former
passenger liner
A passenger ship is a merchant ship whose primary function is to carry passengers on the sea. The category does not include cargo vessels which have accommodations for limited numbers of passengers, such as the ubiquitous twelve-passenger freig ...
, was moored in
Doubtful Sound
Doubtful Sound / Patea is a fiord in Fiordland, in the far south west of New Zealand. It is located in the same region as the smaller but more famous and accessible Milford Sound / Piopiotahi. It took second place after Milford Sound as New Zea ...
to be used as a hostel for workers building the tailrace tunnel. During the 1930s she was a top-rated trans-Tasman passenger liner, with accommodation for 304 first-class passengers. She continued to serve as a hostel until December 1969.
*February 1964, tailrace-tunnel construction began.
*December 1967, powerhouse construction was completed.
*October 1968, tunnel breakthrough.
*14 September 1969, the first water flowed through the power station.
*September/October 1969, commissioning of the first four generators.
*August/September 1971, the remaining three generators were commissioned.
*1972, the station was commissioned. It was then that engineers confirmed the limitations of peak capacity due to excess friction in the tailrace tunnel.
*June 1997, construction work by a
Dillingham Construction
Dillingham Construction was an engineering and construction services company which was based in Hawaii then in Pleasanton, California. The company was founded in the 1880s as the Oahu Railway and Land Company to build a railroad across the swamps ...
/
Fletcher Construction
The Fletcher Construction Company Limited is a New Zealand construction company and a subsidiary of Fletcher Building. Together with Higgins Contractors Ltd it makes up the Construction division of Fletcher Building. Fletcher Construction is wid ...
/
Ilbau joint venture began on the second tailrace tunnel.
*1998, the Robbins
tunnel boring machine
A tunnel boring machine (TBM), also known as a "mole", is a machine used to excavate tunnels with a circular cross section through a variety of soil and rock strata. They may also be used for microtunneling. They can be designed to bore thro ...
starts drilling at the
Deep Cove end of the tunnel.
*2001, tunnel breakthrough.
*2002, the second tunnel was commissioned. A $98 million mid-life refurbishment of the seven generator units begins, with the goal of raising their eventual output to 135 MVA (121.5 MW) each. By June 2006, four generating units had been upgraded, and the project was on schedule for completion in August 2007. By the end of 2007, all seven turbines had been upgraded.
*2014, three transformers were replaced following the discovery of an issue with the oil cooler on one of Manapōuri's seven transformers during maintenance in March. The first removed transformer was the largest pieces of hardware to leave the station since its completion. The three transformers were replaced with newly manufactured ones, delivered via Wilmot Pass between December 2014 and February 2015.
Political history
In July 1956, the New Zealand Electricity Department announced the possibility of a project using the Manapōuri water, an underground power station and underground tailrace tunnel discharging the water at ''Deep Cove'' in
Doubtful Sound
Doubtful Sound / Patea is a fiord in Fiordland, in the far south west of New Zealand. It is located in the same region as the smaller but more famous and accessible Milford Sound / Piopiotahi. It took second place after Milford Sound as New Zea ...
. Five months later, Consolidated Zinc Proprietary Limited (later known as Comalco) formally approached the New Zealand government about acquiring a large amount of electricity for aluminium smelting.
On 2 May 1961
Stan Goosman for the Ministry of Works for the First National Government, signed an agreement making it binding on any future government for this project to go ahead, On 19 January 1960, the
Labour Government and Consolidated Zinc/Comalco signed a formal agreement for Consolidated Zinc to build both an aluminium smelter at Tiwai Point and a power station in Manapōuri. The agreement violated the National Parks Act, which provided for formal protection of the Park, and required subsequent legislation to validate the development. Consolidated Zinc/Comalco received exclusive rights to the waters of both Lakes Manapōuri and Te Anau for 99 years. Consolidated Zinc/Comalco planned to build dams that would raise Lake Manapōuri by , and merge the two lakes. The
Save Manapouri Campaign
The Save Manapouri campaign was an environmental campaign waged between 1969 and 1972 in New Zealand to prevent the raising of the levels of lakes Manapouri and Te Anau as part of the construction of the Manapouri Power Project.
Origins
The ...
was born, marking the beginning of the modern New Zealand environmental movement.
In 1963, Consolidated Zinc/Comalco decided it could not afford to build the power station. The New Zealand government took over. Electricity generated by the plant was sold to Consolidated Zinc/Comalco at under an arrangement designed to return the cost of building the power station to the government.
In 1969, Consolidated Zinc's electric power rights were transferred to Comalco Power (NZ) Ltd, a subsidiary of the Australian-based
Comalco Industries Pty Ltd.
In 1970, the
Save Manapouri Campaign
The Save Manapouri campaign was an environmental campaign waged between 1969 and 1972 in New Zealand to prevent the raising of the levels of lakes Manapouri and Te Anau as part of the construction of the Manapouri Power Project.
Origins
The ...
organised a petition to Parliament opposing raising the water level of Lake Manapōuri. The petition attracted 264,907 signatures, equivalent to nearly 10 percent of New Zealand's population at the time.
In 1972, New Zealand elected a new Labour government. In 1973, the Prime Minister,
Norman Kirk
Norman Eric Kirk (6 January 1923 – 31 August 1974) was a New Zealand politician who served as the 29th prime minister of New Zealand from 1972 until his sudden death in 1974.
Born into poverty in Southern Canterbury, Kirk left school at ...
, honoured his party's election pledge not to raise the levels of the lakes. He created an independent body, the
Guardians of Lake Manapōuri, Monowai, and Te Anau, to oversee management of the lake levels. The original six ''Guardians'' were all prominent leaders of the
Save Manapouri Campaign
The Save Manapouri campaign was an environmental campaign waged between 1969 and 1972 in New Zealand to prevent the raising of the levels of lakes Manapouri and Te Anau as part of the construction of the Manapouri Power Project.
Origins
The ...
.
In 1984, the
Labour Party returned to power in the
general election
A general election is a political voting election where generally all or most members of a given political body are chosen. These are usually held for a nation, state, or territory's primary legislative body, and are different from by-elections ( ...
. The resulting period was tumultuous, with Labour's controversial ministers
Roger Douglas
Sir Roger Owen Douglas (born 5 December 1937) is a retired New Zealand politician who served as a minister in two Labour governments. He became arguably best known for his prominent role in New Zealand's radical economic restructuring in the 19 ...
and
Richard Prebble
Richard William Prebble (born 7 February 1948) is a former member of the New Zealand Parliament. Initially a member of the Labour Party, he joined the newly formed ACT New Zealand party under Roger Douglas in 1996, becoming its leader from 19 ...
driving
rogernomics
In February 1985, journalists at the '' New Zealand Listener'' coined the term Rogernomics, a portmanteau of "Roger" and "economics" (by analogy with "Reaganomics"), to describe the neoliberal economic policies followed by Roger Douglas. Dougl ...
, a rapid introduction of "
free market
In economics, a free market is an economic system in which the prices of goods and services are determined by supply and demand expressed by sellers and buyers. Such markets, as modeled, operate without the intervention of government or any o ...
" reforms and
privatisation
Privatization (also privatisation in British English) can mean several different things, most commonly referring to moving something from the public sector into the private sector. It is also sometimes used as a synonym for deregulation when ...
of government assets. Many suspected the Manapōuri Power station would be sold, and Comalco was the obvious buyer. In 1991, the
Save Manapouri Campaign
The Save Manapouri campaign was an environmental campaign waged between 1969 and 1972 in New Zealand to prevent the raising of the levels of lakes Manapouri and Te Anau as part of the construction of the Manapouri Power Project.
Origins
The ...
was revived, with many of the same leaders and renamed ''Power For Our Future''. The Campaign opposed selling off the power station to ensure that Comalco did not rehabilitate its plans to raise Lake Manapouri's waters. The Campaign was successful. The government announced that Manapōuri would not be sold to Comalco.
On 1 April 1999 - the 1998 reform of the New Zealand electricity sector took effect: the Electricity Corporation of New Zealand was broken up and Manapōuri was transferred to new state-owned generator
Meridian Energy
Meridian Energy Limited is a New Zealand electricity generator and retailer. The company generates the largest proportion of New Zealand's electricity, generating 35 percent of the country's electricity in the year ending December 2014, and is ...
.
In 2002, the Government rejected an application of a business, Southland Water 2000, to bottle 40,000 cubic metres of water in 20 hours, twelve times a year, before the water from the power station is released into Doubtful Sound.
In July 2020,
Rio Tinto Rio Tinto, meaning "red river", may refer to:
Businesses
* Rio Tinto (corporation), an Anglo-Australian multinational mining and resources corporation
** Rio Tinto Alcan, based in Canada
** Rio Tinto Borax in America
*** Rio Tinto Borax Mine, ...
announced that they would be closing the
aluminium smelter
Aluminium smelting is the process of extracting aluminium from its oxide, alumina, generally by the Hall-Héroult process. Alumina is extracted from the ore bauxite by means of the Bayer process at an alumina refinery.
This is an electrolyti ...
in
Bluff
Bluff or The Bluff may refer to:
Places Australia
* Bluff, Queensland, Australia, a town
* The Bluff, Queensland (Ipswich), a rural locality in the city of Ipswich
* The Bluff, Queensland (Toowoomba Region), a rural locality
* Bluff River (New ...
in August 2021, triggering discussions on how to utilise the energy generated in Manapouri. In January 2021, Rio Tinto said they would keep the smelter open until December 2024.
Specifications and statistics
Power station
Civil engineering
Operation
The massive inertia of the column of water in the long tailrace tunnel makes rapid changes to Manapōuri's generation difficult. Further, because the tailrace tunnel emerges at sea level in Deep Cove, power production can be influenced by the state of the tide there. The maximum tidal range is 2·3 metres (7'8") which is a little over one percent of the station's head. The plot shows a variation of about 5MW linked not to the usual twenty-four-hour cycle of electricity usage but to the times of high and low tide, which cycle around the clock.
Transmission
Manapōuri is connected to the rest of the
National Grid via two double-circuit 220 kV transmission lines. One line connects Manapōuri to Tiwai Point via North Makarewa substation, north of Invercargill, while the other line connects Manapōuri to Invercargill substation, with one circuit also connecting to North Makarewa substation. Another double-circuit 220 kV line connects Invercargill to Tiwai Point.
If Tiwai Point reduced demand or closed, Manapōuri generation would have to be reduced to prevent overloading the transmission lines out of the lower South Island. The Clutha Upper Waitaki Lines Project (CULWP) is under construction to relieve this constraint, allowing an extra 400 megawatts to be sent north.
References
Bibliography
*Fox, Aaron P.,''The Power Game: the development of the Manapouri-Tiwai Point electro-industrial complex, 1904-1969'' PhD Thesis, University of Otago, Dunedin, (2001) http://otago.ourarchive.ac.nz/handle/10523/335
*
Peat, Neville. ''Manapouri Saved!: New Zealand's first great conservation success story: integrating nature conservation with hydro-electric development of Lakes Manapouri and Te Anau, Fiordland National Park'' Longacre Press, Dunedin (1994)
''Integrating Nature Conservation with Hydro-Electric Development: Conflict Resolution with Lakes Manapouri and Te Anau, Fiordland National Park, New Zealand''- Mark, Alan; professor, environmentalist, member of the 'Guardians of Lake Manapouri' institution
*''Manapouri - the Toughest Tunnel'', a 60-minute television documentary made in 2002 by
NHNZ
NHNZ, formerly Natural History New Zealand, is a New Zealand-based television production house.
It works and co-produces with multiple major global broadcasters: Discovery Channel, Animal Planet, Discovery Science, A&E Television Networks, Na ...
Notes
External links
Power station info page from
Meridian Energy
Meridian Energy Limited is a New Zealand electricity generator and retailer. The company generates the largest proportion of New Zealand's electricity, generating 35 percent of the country's electricity in the year ending December 2014, and is ...
{{Meridian Energy, state=autocollapse
Energy infrastructure completed in 1971
Hydroelectric power stations in New Zealand
Fiordland
Buildings and structures in Southland, New Zealand
Dam controversies
Underground power stations