104-637: The Waitaki Dam is one of eight hydroelectric power stations which form the Waitaki hydroelectric scheme on the Waitaki River in the Canterbury Region of New Zealand. The dam was the first of three to be built on the Waitaki River and was constructed without earthmoving machinery; over half a million cubic metres of material was excavated, almost entirely by pick-and-shovel. The Waitaki Dam's construction
208-737: A greenhouse gas . According to the World Commission on Dams report, where the reservoir is large compared to the generating capacity (less than 100 watts per square metre of surface area) and no clearing of the forests in the area was undertaken prior to impoundment of the reservoir, greenhouse gas emissions from the reservoir may be higher than those of a conventional oil-fired thermal generation plant. In boreal reservoirs of Canada and Northern Europe, however, greenhouse gas emissions are typically only 2% to 8% of any kind of conventional fossil-fuel thermal generation. A new class of underwater logging operation that targets drowned forests can mitigate
312-463: A low-head hydro power plant with hydrostatic head of few meters to few tens of meters can be classified either as an SHP or an LHP. The other distinction between SHP and LHP is the degree of the water flow regulation: a typical SHP primarily uses the natural water discharge with very little regulation in comparison to an LHP. Therefore, the term SHP is frequently used as a synonym for the run-of-the-river power plant . The largest power producers in
416-514: A trellis bridge being erected across the river and completed in December 1928. This enabled the construction of several cofferdams so that the foundations of the dam could be excavated and concrete subsequently poured. The construction of the first cofferdam was a narrow dam section in the centre of the river. This was followed by the cofferdam on the Canterbury (north) side of the river and restricted
520-421: A flood and fail. Changes in the amount of river flow will correlate with the amount of energy produced by a dam. Lower river flows will reduce the amount of live storage in a reservoir therefore reducing the amount of water that can be used for hydroelectricity. The result of diminished river flow can be power shortages in areas that depend heavily on hydroelectric power. The risk of flow shortage may increase as
624-533: A further two generators were added between 1952 and 1954. With seven generators each delivering 15 MW, the total generative output of the Waitaki Dam is 105 MW. The first State-built power station in New Zealand was constructed at Lake Coleridge in 1915 – designed to supply Christchurch and any additional consumer demand within reach of the transmission system. Consumers quickly tapped into this low-cost energy and
728-414: A gad ( digging bar ) and sledge hammer. Men did most of the overburden stripping and loading by hand-shovel, but used an Osgood dragline when the excavation was from deeper water. The lack of heavy earthmoving equipment during the dam's construction meant that pick, shovel and wheel barrow were commonly used, although trucks run on light railways around the dam site were used extensively. Construction of
832-460: A general service to members of the Association and their families for a small subscription. The doctor for much of the project was Gervan McMillan , a young idealist who worked tirelessly for the Association and was to play an integral role in the development of the social welfare system trialled at Waitaki. McMillan, along with Arnold Nordmeyer , Kurow's Presbyterian Minister, and Andrew Davidson ,
936-494: A hydroelectric complex is constructed, it produces no direct waste, and almost always emits considerably less greenhouse gas than fossil fuel -powered energy plants. However, when constructed in lowland rainforest areas, where part of the forest is inundated, substantial amounts of greenhouse gases may be emitted. Construction of a hydroelectric complex can have significant environmental impact, principally in loss of arable land and population displacement. They also disrupt
1040-809: A large natural height difference between two waterways, such as a waterfall or mountain lake. A tunnel is constructed to take water from the high reservoir to the generating hall built in a cavern near the lowest point of the water tunnel and a horizontal tailrace taking water away to the lower outlet waterway. A simple formula for approximating electric power production at a hydroelectric station is: P = − η ( m ˙ g Δ h ) = − η ( ( ρ V ˙ ) g Δ h ) {\displaystyle P=-\eta \ ({\dot {m}}g\ \Delta h)=-\eta \ ((\rho {\dot {V}})\ g\ \Delta h)} where Efficiency
1144-451: A larger amount of methane than those in temperate areas. Like other non-fossil fuel sources, hydropower also has no emissions of sulfur dioxide, nitrogen oxides, or other particulates. Reservoirs created by hydroelectric schemes often provide facilities for water sports , and become tourist attractions themselves. In some countries, aquaculture in reservoirs is common. Multi-use dams installed for irrigation support agriculture with
SECTION 10
#17328560828131248-586: A positive risk adjusted return, unless appropriate risk management measures are put in place. While many hydroelectric projects supply public electricity networks, some are created to serve specific industrial enterprises. Dedicated hydroelectric projects are often built to provide the substantial amounts of electricity needed for aluminium electrolytic plants, for example. The Grand Coulee Dam switched to support Alcoa aluminium in Bellingham, Washington , United States for American World War II airplanes before it
1352-513: A rapid completion was unrealistic. Packwood's first task was to extend a spur from the Kurow Branch railway line to the dam site – a simple 6 km (3.7 mi) extension which was approved and surveyed in August 1928, with Public Works Department traffic operating on the line by December 1928. With the railway and the existing gravel road from Kurow ( SH83 ) providing equipment and material access,
1456-545: A relatively constant water supply. Large hydro dams can control floods, which would otherwise affect people living downstream of the project. Managing dams which are also used for other purposes, such as irrigation , is complicated. In 2021 the IEA called for "robust sustainability standards for all hydropower development with streamlined rules and regulations". Large reservoirs associated with traditional hydroelectric power stations result in submersion of extensive areas upstream of
1560-526: A result of climate change . One study from the Colorado River in the United States suggest that modest climate changes, such as an increase in temperature in 2 degree Celsius resulting in a 10% decline in precipitation, might reduce river run-off by up to 40%. Brazil in particular is vulnerable due to its heavy reliance on hydroelectricity, as increasing temperatures, lower water flow and alterations in
1664-448: A small TV/radio). Even smaller turbines of 200–300 W may power a few homes in a developing country with a drop of only 1 m (3 ft). A Pico-hydro setup is typically run-of-the-river , meaning that dams are not used, but rather pipes divert some of the flow, drop this down a gradient, and through the turbine before returning it to the stream. An underground power station is generally used at large facilities and makes use of
1768-596: A social security system. This was adopted as the basis for New Zealand's national social welfare scheme, which was implemented in 1939 by the Savage Government . The construction of the Waitaki Power Station therefore played an important role in the origin of New Zealand's present Social Security system . Hydroelectricity Hydroelectricity , or hydroelectric power , is electricity generated from hydropower (water power). Hydropower supplies 15% of
1872-455: A source of low-cost renewable energy. Alternatively, small hydro projects may be built in isolated areas that would be uneconomic to serve from a grid, or in areas where there is no national electrical distribution network. Since small hydro projects usually have minimal reservoirs and civil construction work, they are seen as having a relatively low environmental impact compared to large hydro. This decreased environmental impact depends strongly on
1976-414: A start-up time of the order of a few minutes. Although battery power is quicker its capacity is tiny compared to hydro. It takes less than 10 minutes to bring most hydro units from cold start-up to full load; this is quicker than nuclear and almost all fossil fuel power. Power generation can also be decreased quickly when there is a surplus power generation. Hence the limited capacity of hydropower units
2080-410: A station generative capacity of 75 MW, although initially only two 15 MW generators and turbines were ordered. Early designs of the dam, in large part due to the infancy of hydroelectric engineering in New Zealand, had potentially serious flaws. In particular, there was no consideration of the pressure exerted by the hydrostatic head and impact of water entering cracks or joints in either the basement or
2184-581: A total of 1,500 terawatt-hours (TWh) of electrical energy in one full cycle" which was "about 170 times more energy than the global fleet of pumped storage hydropower plants". Battery storage capacity is not expected to overtake pumped storage during the 2020s. When used as peak power to meet demand, hydroelectricity has a higher value than baseload power and a much higher value compared to intermittent energy sources such as wind and solar. Hydroelectric stations have long economic lives, with some plants still in service after 50–100 years. Operating labor cost
SECTION 20
#17328560828132288-466: A turbine had been tested and commissioned. Instead, when the Governor-General threw the switch, lamps in the powerhouse were slowly lit using power from Coleridge. The turbines were tested and commissioned with full power being turned on 1 January 1935. Finalisation work on the dam continued through to July 1935 with sealing of the temporary sluice gates and removal of most of the framework supporting
2392-681: A whole. During the Last Glacial Period when sea levels were over 100 metres lower than present day levels, the North and South islands were connected by a vast coastal plain which formed at the South Taranaki Bight . During this period, most of the North Island was covered in thorn scrubland and forest , while the modern-day Northland Peninsula was a subtropical rainforest . Sea levels began to rise 7,000 years ago, eventually separating
2496-629: A year's worth of rain fell within 24 hours (see 1975 Banqiao Dam failure ). The resulting flood resulted in the deaths of 26,000 people, and another 145,000 from epidemics. Millions were left homeless. The creation of a dam in a geologically inappropriate location may cause disasters such as 1963 disaster at Vajont Dam in Italy, where almost 2,000 people died. North Island The North Island ( Māori : Te Ika-a-Māui [tɛ i.kɐ ɐ mɑː.ʉ.i] , lit. 'the fish of Māui', officially North Island or Te Ika-a-Māui or historically New Ulster )
2600-448: Is hydroelectric power on a scale serving a small community or industrial plant. The definition of a small hydro project varies but a generating capacity of up to 10 megawatts (MW) is generally accepted as the upper limit. This may be stretched to 25 MW and 30 MW in Canada and the United States. Small hydro stations may be connected to conventional electrical distribution networks as
2704-627: Is also usually low, as plants are automated and have few personnel on site during normal operation. Where a dam serves multiple purposes, a hydroelectric station may be added with relatively low construction cost, providing a useful revenue stream to offset the costs of dam operation. It has been calculated that the sale of electricity from the Three Gorges Dam will cover the construction costs after 5 to 8 years of full generation. However, some data shows that in most countries large hydropower dams will be too costly and take too long to build to deliver
2808-466: Is highest in the winter when solar energy is at a minimum. Pico hydro is hydroelectric power generation of under 5 kW . It is useful in small, remote communities that require only a small amount of electricity. For example, the 1.1 kW Intermediate Technology Development Group Pico Hydro Project in Kenya supplies 57 homes with very small electric loads (e.g., a couple of lights and a phone charger, or
2912-459: Is in the North Island", "my mother lives in the North Island". Maps, headings, tables, and adjectival expressions use North Island without "the". According to Māori mythology , the North and South Islands of New Zealand arose through the actions of the demigod Māui . Māui and his brothers were fishing from their canoe (the South Island) when he caught a great fish and pulled it right up from
3016-445: Is initially produced during construction of the project, and some methane is given off annually by reservoirs, hydro has one of the lowest lifecycle greenhouse gas emissions for electricity generation. The low greenhouse gas impact of hydroelectricity is found especially in temperate climates . Greater greenhouse gas emission impacts are found in the tropical regions because the reservoirs of power stations in tropical regions produce
3120-462: Is not an energy source, and appears as a negative number in listings. Run-of-the-river hydroelectric stations are those with small or no reservoir capacity, so that only the water coming from upstream is available for generation at that moment, and any oversupply must pass unused. A constant supply of water from a lake or existing reservoir upstream is a significant advantage in choosing sites for run-of-the-river. A tidal power station makes use of
3224-452: Is not generally used to produce base power except for vacating the flood pool or meeting downstream needs. Instead, it can serve as backup for non-hydro generators. The major advantage of conventional hydroelectric dams with reservoirs is their ability to store water at low cost for dispatch later as high value clean electricity. In 2021, the IEA estimated that the "reservoirs of all existing conventional hydropower plants combined can store
Waitaki Dam - Misplaced Pages Continue
3328-410: Is often higher (that is, closer to 1) with larger and more modern turbines. Annual electric energy production depends on the available water supply. In some installations, the water flow rate can vary by a factor of 10:1 over the course of a year. Hydropower is a flexible source of electricity since stations can be ramped up and down very quickly to adapt to changing energy demands. Hydro turbines have
3432-469: Is one of the two main islands of New Zealand , separated from the larger but less populous South Island by Cook Strait . With an area of 113,729 km (43,911 sq mi), it is the world's 14th-largest island , constituting 43% of New Zealand's land area. It has a population of 4,077,800 (June 2024), which is 76% of New Zealand's residents, making it the most populous island in Polynesia and
3536-448: The 28th-most-populous island in the world. Twelve main urban areas (half of them officially cities) are in the North Island. From north to south, they are Whangārei , Auckland , Hamilton , Tauranga , Rotorua , Gisborne , New Plymouth , Napier , Hastings , Whanganui , Palmerston North , and New Zealand's capital city Wellington , which is located at the south-west tip of the island. The island has been known internationally as
3640-657: The Bonneville Dam in 1937 and being recognized by the Flood Control Act of 1936 as the premier federal flood control agency. Hydroelectric power stations continued to become larger throughout the 20th century. Hydropower was referred to as "white coal". Hoover Dam 's initial 1,345 MW power station was the world's largest hydroelectric power station in 1936; it was eclipsed by the 6,809 MW Grand Coulee Dam in 1942. The Itaipu Dam opened in 1984 in South America as
3744-778: The International Exhibition of Hydropower and Tourism , with over one million visitors 1925. By 1920, when 40% of the power produced in the United States was hydroelectric, the Federal Power Act was enacted into law. The Act created the Federal Power Commission to regulate hydroelectric power stations on federal land and water. As the power stations became larger, their associated dams developed additional purposes, including flood control , irrigation and navigation . Federal funding became necessary for large-scale development, and federally owned corporations, such as
3848-462: The Mackenzie Basin into Lake Benmore before forming the Waitaki River. Several bedrock gorges, separated by small tectonic basins , lie beneath the string of artificial lakes (Benmore, Aviemore, Waitaki) occupying the middle reaches of the fault-controlled Waitaki Valley. Downstream of Kurow, the valley widens to a plain, with paired alluvial terraces on either side of a braided river channel. At
3952-548: The North Island for many years. The Te Reo Māori name for it, Te Ika-a-Māui , also has official recognition but it remains seldom used by most residents. On some 19th-century maps, the North Island is named New Ulster (named after Ulster province in northern Ireland) which was also a province of New Zealand that included the North Island. In 2009 the New Zealand Geographic Board found that, along with
4056-605: The Tennessee Valley Authority (1933) and the Bonneville Power Administration (1937) were created. Additionally, the Bureau of Reclamation which had begun a series of western US irrigation projects in the early 20th century, was now constructing large hydroelectric projects such as the 1928 Hoover Dam . The United States Army Corps of Engineers was also involved in hydroelectric development, completing
4160-569: The Vulcan Street Plant , began operating September 30, 1882, in Appleton, Wisconsin , with an output of about 12.5 kilowatts. By 1886 there were 45 hydroelectric power stations in the United States and Canada; and by 1889 there were 200 in the United States alone. At the beginning of the 20th century, many small hydroelectric power stations were being constructed by commercial companies in mountains near metropolitan areas. Grenoble , France held
4264-506: The potential energy of dammed water driving a water turbine and generator . The power extracted from the water depends on the volume and on the difference in height between the source and the water's outflow. This height difference is called the head . A large pipe (the " penstock ") delivers water from the reservoir to the turbine. This method produces electricity to supply high peak demands by moving water between reservoirs at different elevations. At times of low electrical demand,
Waitaki Dam - Misplaced Pages Continue
4368-427: The weir on 28 September 1934. The completed dam had been constructed with 175,850 m (6,210,000 cu ft) of concrete in the primary superstructure, plus an additional 38,225 m (1,349,900 cu ft) of concrete for the powerhouse. Construction of the powerhouse had proceeded synchronously with the dam. The vast majority of the plant to be installed in the powerhouse was constructed overseas due to
4472-573: The 2023 census, 63.1% of North Islanders identified as European ( Pākehā ), 19.8% as Māori , 10.6% as Pacific peoples , 19.3% as Asian , 1.9% as Middle Eastern/Latin American/African, and 1.1% as other ethnicities. Percentages add to more than 100% as people can identify with more than one ethnicity. Māori form the majority in three districts of the North Island: Kawerau (63.2%), Ōpōtiki (66.2%) and Wairoa (68.5%). Europeans formed
4576-463: The District Engineer in charge of the dam's construction. Packwood's task was to get the power station operational as quickly as possible and involved the completion of the dam across the Waitaki River followed by installation, testing and commissioning of the electrical and mechanical equipment. Given an overly ambitious goal of an operational power station by 1931, it soon became obvious that such
4680-588: The Dryburgh Fault was recognised as an issue, particularly when excavating the Hörnell Gallery. Basement rock had been reduced to gouge across the fault zone which was remediated by excavating and successfully cementing the gouge zone deeper than the competent rock either side of the fault. When the final Awakino site was selected for the dam, the Public Works Department engaged Roland Packwood as
4784-456: The Government's make work scheme and saw the trial of medical welfare where an individual could build a satisfactory life without fear of the inability to cope with age or poverty. Initial construction of the dam began in 1928 and was completed in 1934 with full power being delivered from two 15 MW generators on 1 January 1935. Three additional generators were added between 1940 and 1949 and
4888-463: The IEA released a main-case forecast of 141 GW generated by hydropower over 2022–2027, which is slightly lower than deployment achieved from 2017–2022. Because environmental permitting and construction times are long, they estimate hydropower potential will remain limited, with only an additional 40 GW deemed possible in the accelerated case. In 2021 the IEA said that major modernisation refurbishments are required. Most hydroelectric power comes from
4992-513: The Minister of Works and local MP , John Bitchener and Leader of the Opposition, Michael Joseph Savage . The opening extended to some 300 invited guests who were seated for lunch in the powerhouse – an easy accommodation given only two of the proposed five generators were installed at the time. The official 'switching on' of the power was not possible as testing had not proceeded to the point at which
5096-518: The Otago side (south) of the Waitaki River was of concern to engineers who felt it may act as a leak point beneath any proposed dam. Subsequently, a site further downstream, near the confluence with the Awakino River, was investigated and found to be suitable. The Awakino site, 6 km (3.7 mi) above Kurow , had only 5 m (16 ft) of shingle to remove before solid basement was reached, reducing
5200-508: The South Island, the North Island had no official name. After a public consultation, the board officially named it North Island, or the aforementioned Te Ika-a-Māui, in October 2013. In prose, the two main islands of New Zealand are called the North Island and the South Island , with the definite article. It is also normal to use the preposition in rather than on , for example "Hamilton
5304-437: The South Island, this is solely due to the North Island having higher natural increase (i.e. births minus deaths) and international migration; since the late 1980s, the internal migration flow has been from the North Island to the South Island. In the year to June 2020, the North Island gained 21,950 people from natural increase and 62,710 people from international migration, while losing 3,570 people from internal migration. At
SECTION 50
#17328560828135408-462: The South Island, with the country's largest city, Auckland, and the capital, Wellington, accounting for nearly half of it. There are 30 urban areas in the North Island with a population of 10,000 or more: The sub-national GDP of the North Island was estimated at NZ$ 282.355 billion in 2021 (78% of New Zealand's national GDP). Nine local government regions cover the North Island and its adjacent islands and territorial waters. Healthcare in
5512-579: The Waitaki Dam, the Waitaki River occupies a fault-angle depression between the greywacke of South Canterbury and the schist of North Otago . The valley fill comprises a sequence of Quaternary river and glacial outwash gravels that overlies Upper Tertiary sedimentary strata, which in turn overlies the Mesozoic basement. Both basement and covering sediments have been affected by late Quaternary faulting, including reactivation of earlier Cretaceous fault systems. Geodetic results indicate that strain rates in
5616-459: The Waitaki area suggest that the recurrence interval of large earthquakes is on the order of thousands or tens-of-thousands of years. The primary fault associated with the Waitaki Dam is the Dryburgh Fault; this fault has been noted as having a considerably long recurrence interval of >62 000 years. While the impacts of regional faulting at the time of the dam's construction were not well understood,
5720-466: The Waitaki's flow by about half leading to half of the trellis bridge being swept away during a flood in early 1929. The trellis bridge was repaired allowing the construction of eleven temporary sluice gates to control river flow during construction of the remainder of the dam. Excavation began near the Otago abutment for the powerhouse and intake section of the dam with overburden stripped and necessary blasting of rock. Blast-holes were hand-drilled using
5824-464: The ability to transport particles heavier than itself downstream. This has a negative effect on dams and subsequently their power stations, particularly those on rivers or within catchment areas with high siltation. Siltation can fill a reservoir and reduce its capacity to control floods along with causing additional horizontal pressure on the upstream portion of the dam. Eventually, some reservoirs can become full of sediment and useless or over-top during
5928-595: The balance between stream flow and power production. Micro hydro means hydroelectric power installations that typically produce up to 100 kW of power. These installations can provide power to an isolated home or small community, or are sometimes connected to electric power networks. There are many of these installations around the world, particularly in developing nations as they can provide an economical source of energy without purchase of fuel. Micro hydro systems complement photovoltaic solar energy systems because in many areas water flow, and thus available hydro power,
6032-404: The base of the dam has persisted: further measures to alleviate this issue were introduced in the early 1960s when anchoring cables were drilled from the dam crest into the foundation rock, and again in 2016 when drainage holes were drilled in the foundation of the dam. The Ahuriri, Ōhau, Pukaki and Tekapo rivers rise in glaciated catchments which feed the Waitaki River. These tributaries flow from
6136-411: The circumnavigation of New Zealand. The maps described the North Island as " Ea Heinom Auwe " and " Aeheinomowe ", which recognises the "Fish of Māui" element. Another Māori name that was given to the North Island, but is now used less commonly, is Aotearoa . Use of Aotearoa to describe the North Island fell out of favour in the early 20th century, and it is now a collective Māori name for New Zealand as
6240-447: The conclusion of the Otago gold rush in the 1860s, New Zealand's European population growth has experienced a steady 'Northern drift' as population centres in the North Island have grown faster than those of New Zealand's South Island. This population trend has continued into the twenty-first century, but at a much slower rate. While the North Island's population continues to grow faster than
6344-404: The daily rise and fall of ocean water due to tides; such sources are highly predictable, and if conditions permit construction of reservoirs, can also be dispatchable to generate power during high demand periods. Less common types of hydro schemes use water's kinetic energy or undammed sources such as undershot water wheels . Tidal power is viable in a relatively small number of locations around
SECTION 60
#17328560828136448-569: The dam itself. The downstream slope of the dam was also considered too steep compared to European dams at a ratio of 3:2. Seepage troubles at the North Island's Arapuni Power Station in 1929 caused additional concerns and resulted in a Swedish hydroelectric engineer, Professor Per Hörnell [ sv ] , being brought to New Zealand in 1930. While Professor Hörnell was specifically brought in to consult on remediation measures to be made at Arapuni, he also visited several other hydroelectric sites, including Waitaki. Despite most column inches at
6552-532: The dam used concrete formed from river gravel aggregate. Concrete was poured into a series of blocks that varied in length, but averaged about 50 ft (15m). Construction continued at pace until 3 February 1931 when flooding caused considerable delays. The Depression forced a reduction in workforce which further hampered construction. Workers were reduced from 1230 in December 1930 to 1000 in early 1931 and further reduced to about 500 in June 1932. The Depression also reduced
6656-505: The dams, sometimes destroying biologically rich and productive lowland and riverine valley forests, marshland and grasslands. Damming interrupts the flow of rivers and can harm local ecosystems, and building large dams and reservoirs often involves displacing people and wildlife. The loss of land is often exacerbated by habitat fragmentation of surrounding areas caused by the reservoir. Hydroelectric projects can be disruptive to surrounding aquatic ecosystems both upstream and downstream of
6760-417: The demand for power making completion of the dam less critical, but this was reversed in 1933 when power demand began to increase once again. The Government re-engaged as many unemployed men as possible, increasing the workforce to 900 in early 1934; this number was steadily reduced from August 1934 as the dam's construction reached completion. As the dam neared completion (the last of the dam's concrete blocks
6864-447: The earlier construction of the dam. The final damaged sluice gates would not be finally sealed off until 18 September 1936 when the water levels were low enough to ensure the sluices could be completely blocked. With the reservoir filled, the Waitaki dam has a hydrostatic head of 21 m (69 ft). The initial implementation of two turbines and generators limited the dam's operational output to 30 MW (15 MW per generator). In 1935 this
6968-401: The early 1920s meaning that resettlement would be a very minor issue following inundation by the dam's reservoir. Initial site investigations began in 1925 and would take over two and a half years before a final site was selected. The focus by 1927 was in the vicinity of Wharekuri/Roseneath (between Aviemore and Waitaki dams) which appeared to be most favourable. However, the presence of coal on
7072-690: The effect of forest decay. Another disadvantage of hydroelectric dams is the need to relocate the people living where the reservoirs are planned. In 2000, the World Commission on Dams estimated that dams had physically displaced 40–80 million people worldwide. Because large conventional dammed-hydro facilities hold back large volumes of water, a failure due to poor construction, natural disasters or sabotage can be catastrophic to downriver settlements and infrastructure. During Typhoon Nina in 1975 Banqiao Dam in Southern China failed when more than
7176-399: The excess generation capacity is used to pump water into the higher reservoir, thus providing demand side response . When the demand becomes greater, water is released back into the lower reservoir through a turbine. In 2021 pumped-storage schemes provided almost 85% of the world's 190 GW of grid energy storage and improve the daily capacity factor of the generation system. Pumped storage
7280-485: The flow into the Waitaki River's headwaters, flooding was not expected to exceed 5380 cumecs , a low threat to the safety of any proposed dam. In its middle reaches, the Waitaki River flows through bedrock gorges of low-grade schists , meta-greywackes and greywackes of the Rakaia Terrane. These gorges offered good dam sites with relatively stable rock upon which to build. The Waitaki River was also sparsely populated in
7384-418: The future, while junior staff and single men were accommodated in wooden houses and huts. In all, the Public Works Department were to construct approximately 350 houses and another 700 huts which were primarily located on two river terraces on the true right river bank (south or Otago-side of the river) immediately upstream of the dam. There were four separate living areas in the wider camp: the main camp occupied
7488-575: The headmaster of Kurow School, all had to deal with problems stemming from the Depression. All three were deeply concerned with the problems of health, family, unemployment with its consequent poverty, and old age. Between them, they drafted a system where any individual could build a life without excessive fear of disaster or inability to cope with such problems that may occur during their lifetime. When McMillan and Nordmeyer entered Parliament in 1935 as Cabinet Ministers, they brought with them their draft for
7592-648: The islands and linking the Cook Strait to the Tasman Sea . The North Island has an estimated population of 4,077,800 as of June 2024. The North Island had a population of 3,808,005 at the 2023 New Zealand census , an increase of 213,453 people (5.9%) since the 2018 census , and an increase of 570,957 people (17.6%) since the 2013 census . Of the total population, 733,893 people (19.3%) were aged under 15 years, 743,154 (19.5%) were 15 to 29, 1,721,427 (45.2%) were 30 to 64, and 609,534 (16.0%) were 65 or older. Ever since
7696-552: The lack of specialised manufacturing capability within New Zealand at the time. The installation of the first two turbines and generators (20,000 hp each) was completed by the end of 1933, and the wiring testing and commissioning in 1934. The Waitaki dam was officially opened on the 27 October 1934 by the Governor-General Lord Bledisloe . In attendance with Lord Bledisloe was the Prime Minister, George Forbes ,
7800-492: The largest amount for the region since 1990. Meanwhile, globally, hydropower generation increased by 70 TWh (up 2%) in 2022 and remains the largest renewable energy source, surpassing all other technologies combined. Hydropower has been used since ancient times to grind flour and perform other tasks. In the late 18th century hydraulic power provided the energy source needed for the start of the Industrial Revolution . In
7904-731: The largest, producing 14 GW , but was surpassed in 2008 by the Three Gorges Dam in China at 22.5 GW . Hydroelectricity would eventually supply some countries, including Norway , Democratic Republic of the Congo , Paraguay and Brazil , with over 85% of their electricity. In 2021 the International Energy Agency (IEA) said that more efforts are needed to help limit climate change . Some countries have highly developed their hydropower potential and have very little room for growth: Switzerland produces 88% of its potential and Mexico 80%. In 2022,
8008-609: The late 19th century, the electrical generator was developed and could now be coupled with hydraulics. The growing demand arising from the Industrial Revolution would drive development as well. In 1878, the world's first hydroelectric power scheme was developed at Cragside in Northumberland , England, by William Armstrong . It was used to power a single arc lamp in his art gallery. The old Schoelkopf Power Station No. 1 , US, near Niagara Falls , began to produce electricity in 1881. The first Edison hydroelectric power station,
8112-510: The lower Canterbury region are low to very low, though strain increases considerably toward the west and proximity with the Alpine Fault . The Waitaki region, along with the rest of the south-eastern South Island , has had a low level of large earthquake occurrences in historic times, with one of the largest recorded earthquakes (M5.8) in the vicinity of the Waitaki Dam occurring near Oamaru in 1876. Paleoseismic studies on individual faults in
8216-488: The mid-1700s, French engineer Bernard Forest de Bélidor published Architecture Hydraulique , which described vertical- and horizontal-axis hydraulic machines, and in 1771 Richard Arkwright 's combination of water power , the water frame , and continuous production played a significant part in the development of the factory system, with modern employment practices. In the 1840s, hydraulic power networks were developed to generate and transmit hydro power to end users. By
8320-651: The natural ecology of the river involved, affecting habitats and ecosystems, and siltation and erosion patterns. While dams can ameliorate the risks of flooding, dam failure can be catastrophic. In 2021, global installed hydropower electrical capacity reached almost 1,400 GW, the highest among all renewable energy technologies. Hydroelectricity plays a leading role in countries like Brazil, Norway and China. but there are geographical limits and environmental issues. Tidal power can be used in coastal regions. China added 24 GW in 2022, accounting for nearly three-quarters of global hydropower capacity additions. Europe added 2 GW,
8424-673: The overall volume of material to be excavated. The final site (Awakino) having been selected for the Waitaki Dam was announced by the Government in April 1928, with an overly ambitious target for completion by 1931. The investigations of the Roseneath site were not in vain either – Roseneath would later be adopted as the site of the Aviemore Dam . Engineers calculated that the Awakino site, backed-up by several years of Waitaki River flow records, would support
8528-633: The plant site. Generation of hydroelectric power changes the downstream river environment. Water exiting a turbine usually contains very little suspended sediment, which can lead to scouring of river beds and loss of riverbanks. The turbines also will kill large portions of the fauna passing through, for instance 70% of the eel passing a turbine will perish immediately. Since turbine gates are often opened intermittently, rapid or even daily fluctuations in river flow are observed. Drought and seasonal changes in rainfall can severely limit hydropower. Water may also be lost by evaporation. When water flows it has
8632-465: The plurality in the Auckland region (49.8%) and are the majority in the remaining 39 districts. The proportion of North Islanders born overseas at the 2018 census were 29.3%. The most common foreign countries of birth were England (15.4% of overseas-born residents), Mainland China (11.3%), India (10.1%), South Africa (5.9%), Australia (5.5%) and Samoa (5.3%). The North Island has a larger population than
8736-434: The powerhouse building roof was also undertaken to ensure it could withstand a major earthquake. Meridian Energy envisages a further phase of upgrades worth $ 90 million being required to replace four of the station's original generation units. Worker safety during the construction of the Waitaki Dam was very limited. Nine men were reported to have died during the construction of the dam; three men died in accidents related to
8840-631: The project was able to start in earnest. Before any major works at the Waitaki site were undertaken, a camp was required to accommodate up to 1000 workers in addition to their families (up to 2000 people in total). The harsh climate of the Waitaki Valley with its cold winters and strong winds, plus the long-term nature of the project, meant the Public Works Department opted for more permanent wooden accommodation in favour of their typical use of canvas tents. Senior staff were allocated houses built of concrete blocks which would become permanent staff quarters in
8944-450: The rainfall regime, could reduce total energy production by 7% annually by the end of the century. Lower positive impacts are found in the tropical regions. In lowland rainforest areas, where inundation of a part of the forest is necessary, it has been noted that the reservoirs of power plants produce substantial amounts of methane . This is due to plant material in flooded areas decaying in an anaerobic environment and forming methane,
9048-423: The refurbishment project saw the drilling of drainage holes in the foundation of the dam to relieve the hydrostatic pressure first raised as a concern by Professor Hörnell in 1930. The station's No. 3 generation unit was also recommissioned during this time: the generator's stator, the single largest component at 120-million tonnes, seized in 1998 and proved uneconomic to return to service at the time. Strengthening of
9152-452: The same time. With seven generators each delivering 15 MW, the total generative output of the Waitaki Dam is 105 MW. Following the installation of the seventh and final generator in 1954, the Waitaki power station had seen no further major upgrades until 2013. Starting in April 2013, a four-year $ 40 million refurbishment of the Waitaki power station was undertaken by Meridian Energy . After almost eighty years of continuous operation, part of
9256-480: The sea. While he was not looking, his brothers fought over the fish and chopped it up. This great fish became the North Island, and thus a Māori name for the North Island is Te Ika-a-Māui ("The Fish of Māui"). The mountains and valleys are believed to have been formed as a result of Māui's brothers' hacking at the fish. During Captain James Cook 's voyage between 1769 and 1770 , Tahitian navigator Tupaia accompanied
9360-468: The time focussing on the exorbitant £4000 consultant's fee charged by Professor Hörnell, his comments on the Waitaki were that its cross section was too narrow and that measures should be incorporated to ensure adequate foundation drainage. Notwithstanding the Government's decision not to invest in a specific Waitaki Dam report from Professor Hörnell, several design modifications were made on the basis of his comments: Despite these additions, Professor Hörnell
9464-399: The upper terrace, 'Siberia' was located on the lower river terrace (so-named because it was exposed to the cold winds), 'Geddesville' was located downstream from the construction site, and 'Willows', located close to the Awakino bridge. In addition to accommodation, the camp included a YMCA hall, post office, small shops, tennis courts and a football ground. At the dam's completion, the camp
9568-421: The use of heavily laden trucks on the dam's steeply-inclined sections of light railway, while another three drowned in the river. Accidents were extremely prevalent – in one year alone, 540 cases of injuries were reported, although the severity of these injuries is unknown. By way of comparison and considering a worker population of approximately 1000 at Waitaki, the incidence rate of all injury claims in New Zealand
9672-400: The village as a historic area in 1995. After passing through several owners it went up for sale in 2015 but languished unsold for several years. Interest in purchasing Lake Waitaki village was rejuvenated in 2018, when global media outlets caught hold of the story that a village was up for sale. Lake Waitaki village now serves as accommodation for vacation rentals. Dam construction began with
9776-524: The world are hydroelectric power stations, with some hydroelectric facilities capable of generating more than double the installed capacities of the current largest nuclear power stations . Although no official definition exists for the capacity range of large hydroelectric power stations, facilities from over a few hundred megawatts are generally considered large hydroelectric facilities. Currently, only seven facilities over 10 GW ( 10,000 MW ) are in operation worldwide, see table below. Small hydro
9880-533: The world's electricity , almost 4,210 TWh in 2023, which is more than all other renewable sources combined and also more than nuclear power . Hydropower can provide large amounts of low-carbon electricity on demand, making it a key element for creating secure and clean electricity supply systems. A hydroelectric power station that has a dam and reservoir is a flexible source, since the amount of electricity produced can be increased or decreased in seconds or minutes in response to varying electricity demand. Once
9984-539: The world. The classification of hydropower plants starts with two top-level categories: The classification of a plant as an SHP or LHP is primarily based on its nameplate capacity , the threshold varies by the country, but in any case a plant with the capacity of 50 MW or more is considered an LHP. As an example, for China, SHP power is below 25 MW, for India - below 15 MW, most of Europe - below 10 MW. The SHP and LHP categories are further subdivided into many subcategories that are not mutually exclusive. For example,
10088-401: The year-on-year load increase for Coleridge was 15%; by the 1920s a new power source was needed. The Waitaki River was selected as the most promising source of hydro-electric power, particularly for long-term needs – the New Zealand government having recognised the electricity generation potential of the Waitaki Valley as early as 1904. With Lakes Ōhau , Pukaki and Tekapo controlling 80% of
10192-523: Was 87 claims per 1000 full-time equivalent employees in 2022. In Public Works Department camps large-enough to warrant it, a medical association with resident doctor and/or nurse would be supplied. At the start of the Waitaki Dam project, the camp numbers did not justify a resident nurse so the doctor's surgery at Kurow was used. On 1 November 1928, the Waitaki Hydro Medical Association was formed in agreement with Kurow's doctor to provide
10296-573: Was allowed to provide irrigation and power to citizens (in addition to aluminium power) after the war. In Suriname , the Brokopondo Reservoir was constructed to provide electricity for the Alcoa aluminium industry. New Zealand 's Manapouri Power Station was constructed to supply electricity to the aluminium smelter at Tiwai Point . Since hydroelectric dams do not use fuel, power generation does not produce carbon dioxide . While carbon dioxide
10400-467: Was dismantled apart from the permanent structures of Lake Waitaki village which were occupied by the permanent dam staff. When the Electricity Corporation of NZ (ECNZ) moved its staff out in the 1980s, the remaining concrete block houses, hostel and environs were threatened with demolition. However, pressure from the community resulted in a heritage covenant with Heritage New Zealand to protect
10504-474: Was followed by the development of Aviemore Dam and Benmore Dam , and importantly, every dam built in New Zealand since the Waitaki has benefited from lessons learned during its construction. The Waitaki Dam is unique; its construction lead to the germination of one of the world's first social welfare systems . Built during the Great Depression , the Waitaki Dam attempted to soak up unemployment as part of
10608-406: Was not completely satisfied and his last communication with the Minister of Public Works was to disclaim any responsibility for any future troubles that might occur. Nevertheless, his visit to Waitaki had the significant result of introducing New Zealand engineers to the problem of dealing with water under pressure within the actual structure of a dam. Concern over the possibility of uplift forces on
10712-454: Was poured in mid-June 1934), closure and concreting of the temporary sluice gates began in July 1934. The last sluice gates were not lowered until September 1934, although not without incident – the gates breaking their supporting beams as they were lowered. Despite the last three sluice gates not having stopped head pond water flowing past them completely, the dam continued to fill, finally overtopping
10816-455: Was sufficient to supply half of the South Island's energy requirements. Three additional generators were added between 1940 and 1949 and a further two generators were added between 1952 and 1954. During the phase of work to add the final two generators, the powerhouse was extended from 109 m (358 ft) length to its present length of 152 m (499 ft) to accommodate the new generators. A new inlet and outlet channel were constructed at
#812187