Discover the Waitaki Hydro Scheme Auckland Activity guide Skiing Fishing Canals

Lookout Picnic Water skiing Boating Wellington Lake Tekapo Information Power station Camping Bush walks Waitaki A Tekapo Pukaki There are many places of historical, scenic and Tekapo B recreational interest in the Waitaki Valley Pukaki visitor centre Mount John, an astronomical observatory, is If you would like to find out more about things Lake A located on the shores of Lake Tekapo. to do in the Waitaki Valley please contact the Ohau is renowned for its scenic views of Aoraki – Mount following: Benmore visitor centre Cook, and the mountain’s visitor centre is located Kurow Heritage Centre and power station close to the Pukaki high dam. Lake Ruataniwha Lake Phone 03 436 0950 hosts national rowing competitions every year. Benmore Email [email protected] The Ohau ski area, behind , is one of the few ski fields on the main divide i-site information centre of the Southern Alps. The surrounding Mackenzie Phone 03 434 1656 Email [email protected] Basin was named after sheep rustler James Mackenzie in 1855. The area is sheep farming Twizel information centre country, and in 1895 a third of a million sheep Phone 03 435 3124 perished in a snowstorm. A statue of a sheep Email [email protected] dog at the Church of the Good Shepherd by Tekapo pays tribute to James Mackenzie’s dog. Waitaki The Waitaki hydro scheme consists of eight power stations from Lake Tekapo to . All eight are operated from a control centre in Twizel, which ensures that as much electricity as possible is generated The birthplace of the from the water flowing from the Southern Alps out to the sea. It started as early as 1904 when Mr P S Hay, who worked in the government’s Public Works world’s first social security system Department, recognised the electricity generation potential of the Waitaki Valley. However, it was not until the 1920s that it was possible to begin such a large-scale project. At that time, the Waitaki was a ‘make work’ project during the 1930s depression and spawned the trial Lake Coleridge power station could no longer meet the electricity demand of the , scheme of the world’s first social security system. The station is 8 kilometres upstream so further development was considered necessary. from the township of Kurow, where its doctor, D G McMillan, agreed to provide free medical treatment to workers and their families if they paid a small weekly sum into a common fund. Later, Dr McMillan and Kurow’s Presbyterian Minister, Arnold Nordmeyer, became Cabinet Ministers and helped instigate a similar scheme for the whole country. It became official in 1939. Four new power stations

The ambitious Upper Waitaki hydro scheme began in 1970 and Tekapo B power station was commissioned in 1977. Work continued for 15 years until 1985 when the last station, Ohau C, was commissioned. During that period, four power stations were constructed, along with two dams and six canals (totalling 56 kilometres).

Bailey Bridge Crossing. Meridian – New Zealand’s green electricity leader Hydro scheme towns At Meridian, we take our responsibilities to New Zealand and the environment very seriously. We generate all our electricity using renewable resources and Otematata Twizel work closely with local organisations and the Department of Conservation to Otematata Township was developed in the Twizel Township was built specifically as a preserve the natural environment and protect native plant and animal life. late 1950s to house the workforce needed to residential base for workers on the Upper build the Benmore and Aviemore dams and Waitaki hydro scheme. Its name is taken from power stations. Its population swelled to over the that flows nearby. In 1977, 11 We have made a commitment to sustainable We work with organisations like the Energy 4,000 in 1963, but when the Ministry of Works years after it was established, Twizel reached energy. Our electricity is generated using only Efficiency and Conservation Authority (EECA) staff transferred to Twizel in the late 1960s, its maximum population of 6,000, and the renewable resources – water and wind. to bring New Zealanders ways to save energy many of the houses in Otematata were sold as local primary school became the largest in the and we are constantly on the lookout for new We’re wholly owned and operated by the people holiday homes. Now Otematata is a popular country, with 1,000 pupils. Twizel’s population energy-efficient products and processes to help of New Zealand, and we’re committed to meeting holiday destination, with lakes, rivers, camping dwindled to around 1,300 after the bulk of New Zealanders use electricity wisely. Using our the energy needs of this country by increasing grounds and a golf course within easy reach. the Waitaki development was completed in resources wisely and efficiently helps protect our the efficiency of our generation assets and the mid-1980s, and the current focus of the environment and helps ensure we have ongoing investigating other economical methods of new community is tourism. energy supplies for future generations. generation – such as wind. The Māori name ‘Otematata’ means

We are proud of our involvement with local place of good flint. communities, through community and sporting activities and the arts, and with non-profit organisations. Condensation Precipitation FACT KEY ENERGY EXPLAINED As the vapour rises, it cools Water falls to the earth in the form One cubic metre of water LAKE Cumec one cubic metre of and changes to droplets. of rain, snow, sleet or hail. passing through the eight power GENERATION water fl owing past a stations of the Waitaki system given point every second. generates 2,500 kWh – about CANAL 30% of an average household’s kW 1,000 watts. AVERAGE ANNUAL annual power needs. * How the Waitaki system works GENERATION MW 1,000 kW.

Facts about electricity generation from Mt Cook through the Waitaki System. GWh 1,000 MW passing through a given point Benmore over an hour. Commissioned: 1965 Tekapo A Tekapo canal Lake Ohau Ohau B and C *Annual generation: (Facts are the same for Commissioned: 1951 Length: 25.5 km Storage: 22.02 GWh 2,215 GWh *Annual generation: 160 GWh Lake Pukaki each station) Station generation Commissioned: 1984 - 1985 output: 540 MW Station generation output: 25.5 MW Storage: Number of generating units: 1 x 25.5 MW *Annual generation: 958 GWh Number of generating 1679.65 GWh Commissioned: 1979 Net head: 30.5 m Station generation output: units: 6 x 90 MW Evaporation Tekapo B *Annual generation: Turbine type: Kaplan 212 MW Net head: 92 m Water evaporates Commissioned: 1977 1,140 GWh Generator details: 11 kV Number of generating units: Turbine type: Francis from the surface of *Annual generation: 833 GWh Station generation 4 x 55.5 MW Generator details: the ocean. Station generation output: 160 MW output: 264 MW Net head: 47.5 m 6 x 16 kV Number of generating units: 2 x 80 MW Number of generating Turbine type: 4 Francis Net head: 145.7 m units: 4 x 66 MW Lake Tekapo Generator details: 4 x 11 kV Aviemore Turbine type: Francis Net head: 59 m Storage: 782.36 GWh Commissioned: 1968 Generator details: 11 kV Turbine type: Francis Ohau B Ohau C *Annual generation: Pacifi c Pukaki canal Generator details: Ohau C to Benmore 942 GWh Length: 12 km 4 x 13.2 kV Ocean Aoraki Mt Cook Canal length: 0.5 km Station generation Lake Ruataniwha output: 220 MW 3,754 m Waitaki Storage: 0.87 GWh Number of generating Commissioned: 1935 - 1954 units: 4 x 55 MW *Annual generation: 496 GWh Net head: 37 m Storage: 24.45 GWh Station generation output: 105 MW Turbine type: Francis Number of generating units: Generator details: Tekapo 7 x 15 MW 4 x 11 kV Lake Waitaki Twizel Net head: 21.5 m Storage: 0.54 GWh Turbine type: Francis Generator details: 7 x 11 kV Ohau B canal Otematata Length: 2.4 km Kurow Duntroon Ohau C canal Lake Aviemore Length: 8 km Storage: 2.18 GWh Tekapo A Did you know? The average household consumes around Construction of the Tekapo A power station manufactured by Tampella of Finland, was 10,000 kWh/year (or 10 MWh). Tekapo A Life in Tekapo village started in 1938, and was due to be finished in installed. Its more efficient design and water power station generates an average of Tekapo village, where the workers lived, was very 1943, but work stopped in 1942 as manpower and usage enable it to work at 42,000 horsepower 160 GWh per year – enough energy to power isolated during construction of the power station. materials were concentrated on the war effort. and produce more electricity using less water. the equivalent of 16,000 average households. There were no movie theatres and the nearest Building resumed in 1944 and large camps Tekapo A control gates pub was at , over 20 kilometres away. housing over 500 people were established. The The control gates, which are located in Tekapo Workers kept themselves busy by organising In the 1970s, a 26-kilometre canal was station was finally commissioned in 1951. It was village, were constructed in the 1940s to regulate parties, card evenings, ice-skating in winter or constructed to take outflows from Tekapo A to the second station to be built as part of the Tekapo water outflows to the Waitaki dam. During picnics by the lakeside in summer. Very few people Lake Pukaki, which now enables the water to be Waitaki hydro scheme. the construction of Tekapo A, a 1.4-kilometre owned cars – even six years after the war – but In 1986, three of the seven turbine blades broke tunnel was constructed to divert water from Lake used by four other power stations before entering those who did shared them in emergencies, such off, causing major damage. A new turbine, Tekapo to the Tekapo A power station. Lake Benmore. as a hurried dash to Fairlie for the birth of a baby.

View towards Tekapo A. Did you know? The rotors for the Tekapo B generators were the heaviest objects lifted during the project. They weighed 122 tonnes each.

Tekapo B

Tekapo B was the second station to be built level. Tekapo B connects with the shore by a in the Upper Waitaki hydro scheme and was 75-metre-long bridge. The Pukaki high dam commissioned in 1977. Constructing the foundations for the power In the 1940s, a dam built at Lake Pukaki It was constructed on dry land but designed station proved to be a challenge. The bedrock raised the lake level by 9 metres from its to operate essentially as an island when was too deep – up to 1.6 kilometres under the original maximum depth of 62 metres. the level of Lake Pukaki was raised. It is the glacial clay and sediment – so hefty concrete Thirty years later, this first dam was replaced only power station in New Zealand to be raft foundations were built, and the power by the Pukaki high dam and the level was surrounded entirely by water. Nearly two-thirds station, which is 46 metres high or as tall as raised a further 37 metres. This provided an a 14-storey building, was constructed on of the station is below the water line, and it additional 200 GWh of energy per year. is waterproofed above the maximum lake these instead. Benmore. Ohau A.

Did you know? Benmore Lake Benmore is the country’s largest Benmore power station has New Zealand’s largest man-made lake; it is 74.5 square solid-earth dam and New Zealand’s largest man- kilometres, with a shoreline of 116 made lake – Lake Benmore. The dam’s construction kilometres. It holds 1.5 times more was the biggest job of its kind undertaken in water than Wellington Harbour. New Zealand – and at 540 MW, it’s the country’s second largest hydro station after (840 MW). Benmore power station was commissioned in 1965. Aviemore Did you know? In the 1920s, the Aviemore site was identified design that was unique in the South Island. as an alternative to the Waitaki site for power A diversion tunnel was built, which took the The Aviemore power station has the first artificial trout spawning stream in generation. It wasn’t chosen at the time but outflow from the lake while the dam was being New Zealand. It is a 1-kilometre hairpin-shaped in 1961 the Electric Power Development Board constructed. Its construction saw the country’s channel above the Aviemore tailrace, which recommended that Aviemore be built to start first large-scale use of low-heat cement, which channels the water that flows out of the power generating in 1968. allows a record rate of concrete to be poured station. The tailrace allows trout to migrate Construction began in 1962 and presented some without using cooling coils. Aviemore also has the upstream from Lake Waitaki to spawning unusual challenges. Because part of the dam largest steel penstocks (the pipes that bring the grounds close to the dam in Lake Aviemore. had to be built across a fault line, it had to be water into the powerhouse) of any power station Up to 3,000 adult trout can fit in the tailrace constructed from both concrete and earth, a in New Zealand – 7 metres in diameter. at any one time.

Aviemore. Ohau A Ohau A power station is located on the man-made Pukaki-Ohau canal and it joins Did you know? the water flows from Lake Ohau with those from Lake Tekapo and Lake Pukaki. As part of the completed Upper Waitaki development, the Lower Ohau River Ohau A power station is located on the man-made was no rock foundation so substantial concrete is filled when water is discharged or Pukaki-Ohau canal and it joins the water flows foundations had to be built. spilled into it because of excess water from Lake Ohau with those from Lake Tekapo and Until the Ohau canal was built, water flows from levels, if one of the stations needs to be Lake Pukaki. Approximately 2 million cubic metres the lakes didn’t join until Benmore, and uniting shut down, or when water is needed for of rock and gravel – around half a million concrete the water flows at this earlier location recreational uses. The Upper Ohau River truck loads – was excavated from the northern considerably increased the hydraulic potential runs at 8-12 cumecs between Lake Ohau bank of the Ohau River, and another half a million – the amount of energy that the power stations and Lake Ruataniwha. cubic metres was removed for the tailrace – can extract from the water. Water from Ohau A the tunnel that channels the water out of the also passes through the Ohau River into man-made station. Construction of the power station began Lake Ruataniwha, which was formed by the and in 1971 and it was commissioned in 1979. There construction of the Ruataniwha dam. Ohau B Ohau C These ‘twin’ stations have the same generating Ohau B allows water to be discharged into the capacity and similar equipment. Water from Lake Ohau River, bypassing Ohau C. This provides Ruataniwha used by Ohau B goes into the Ohau C an emergency overflow, and means Ohau B can canal, which takes it to the Ohau C power station operate if Ohau C is shut down. Ohau B was Did you know? and out into Lake Benmore. Excess water flow is commissioned in 1984 and Ohau C in 1985. This controlled by gates in the Ruataniwha dam and completed the Waitaki hydro scheme as we know Approximately 60,000 cubic metres of concrete, which is about 15,000 truck loads, a spillway ensures that excess water is diverted it today. Each station can add around 958 GWh and around 2,400 tonnes of steel plate, were used to construct four penstocks – the into the Ohau River and down into Lake Benmore. of energy a year to New Zealand’s power large pipes that channel water into the station. They were constructed in 21-metre A labyrinth weir 1.6 kilometres downstream from generation capacity. sections with a diameter of 5.8 metres, and weighed 59 to 63 tonnes each. Waitaki Did you know? The first power station to be built on the Waitaki the improved water flow. The station’s sixth and While the other stations on the Waitaki hydro scheme were was named after the river itself and the Waitaki seventh generators – each 15 MW – were installed built using massive earth-moving machinery, the Waitaki dam dam was also the first in New Zealand to be built in 1954, and the station increased its capacity to was the last to be built using picks, shovels and wheelbarrows. without diverting the natural river flow. It was the present-day level of 105 MW. The workers were housed in large camps and conditions were constructed in two parts, starting with a cofferdam harsh – they lived through cold winters and flooding in the (a temporary dam used to hold water during The canals – a major part of the six years that it took to excavate the site and build the dam. construction) to divert water to the (south) Waitaki scheme side of the river. The other part was built on the A major part of the Upper Waitaki development Canterbury (north) side of the river, with 11 sluice was the construction of a system of canals gates enabling water to flow through while the to link the power stations on Lakes Tekapo, second section was being built on the Otago side. Pukaki and Ohau. Entirely man-made from local The station’s powerhouse was completed in 1934 materials and lined with waterproof compacted after the dam was built. It was made of reinforced clay gravels, the canals are designed to take concrete and was 109 metres long. It was advantage of the natural layout of the land. extended to 152 metres in the early 1950s to house All the canals have measures to stop gravel the last set of new generators. The station’s first passing into the powerhouse machinery. Some two generators were commissioned in 1935, and have a settling pond at the end, and all have an a third generator in 1940. Two more generators armour layer of gravel between the canal lining were installed in 1941 and 1949, bringing the and the flowing water. station to its capacity of 75 MW. In 1952 the Pukaki and Tekapo water storage projects were finished, and the power station took advantage of Waitaki aerial. Meridian rowing.

Lake Meridian’s continued commitment to Ruataniwha working with the environment

The development of hydro generation has egg survival rates are two to three times higher Lake Ruataniwha is the newest altered the nature of rivers and lakes in the than elsewhere. lake in the Waitaki Basin and is Waitaki catchment. Some parts of braided rivers To preserve the abundant fishing resource of the have been flooded to create storage lakes and completely man-made. Waitaki, Meridian funds the release of salmon water has been diverted away from other parts smelt in the Lower , and works of these rivers and into canal systems. closely with New Zealand Fish and Game to Built between 1978 and 1981, it has an area of A channel was carved through a low, rocky To help restore and protect this river and monitor trout spawning. only 490 hectares, but its recreational facilities extension of the Benmore Range and covered pristine wetland environment, Meridian funds a And, in conjunction with local iwi, Meridian is make it extremely popular with visitors. It has an with a layer of concrete. To divert the river during conservation programme run by the Department carrying out a programme to enable elver – young international-standard rowing course and the of Conservation – Project River Recovery – which construction, a structure with three diversion eels – to travel safely over the Waitaki dams on New Zealand rowing championships are held was established in 1990 under an agreement sluice gates was built. their way to their maturing grounds upriver and there every second year, alternating with the with the Department. back to their mating sites in the Pacific Islands. national secondary school championships. When the dam was completed, these diversion A total of over 100 hectares of wetlands has gates were closed and the structure turned into been created at four different sites, used by The Ruataniwha dam a spillway, which allows excess water to pass 25 species of water birds (including endangered The Ruataniwha dam created Lake Ruataniwha safely through the dam. Similar to other spillway and threatened species), and native and and forms part of State Highway 8 – the main structures, there are three control gates in the introduced fish. Anti-predator fences surround road to Twizel. Before construction on the dam Ruataniwha spillway, ensuring the maximum some of the wetlands, and within those fences could start, the Ohau River had to be diverted. resource flow will never exceed 1,740 cumecs. Hydro power – how does it work?

A hydro power station works by harnessing falls from the reservoir to the turbine, known as The transformer connects to the national grid generator rotor . Similar to a car alternator, the energy from falling water. The water held the head, determines the amount of energy that at a switchyard, which contains the circuit the generator rotor carries a set of electro- above the power station in a lake or reservoir is can be extracted from a given volume of water. breakers and other connecting switches that magnets that spin within a stationary set of channelled through pipes or penstocks to The turbine extracts the energy from the water allow the generator to be connected and insulated copper windings embedded in an iron disconnected from the grid as required. the turbine . The height from which the water turning it into mechanical energy that spins the core called the stator . Some of the electricity generated into the grid The motion of the magnets within the stator is also converted from AC to direct current (DC), generates electricity in the windings. Most which makes transmission between the two large hydro generators in New Zealand Islands, using special high voltage undersea generate between 11,000 and 16,000 Volts cables in Cook Strait, much more practicable. alternating current (AC), which is not suited to energy-efficient, long distance transmission After passing through the turbine, water exits of electricity. Instead, the generator is connected through a draught tube , back to a river, to a transformer which steps up the voltage canal or lake. – usually to 110,000 or 220,000 Volts AC – to make long distance transmission more practicable and energy efficient. WE’RE HERE TO HELP Please feel free to contact our Customer Service Team. Phone 0800 496 496 Fax 0800 497 498 Monday to Friday, excluding public holidays, between 7.30am and 7.30pm Email [email protected] Website www.meridian.co.nz Address Ltd 322 Manchester Street PO Box 2128 Christchurch

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