Clyde Dam
Encyclopedia
The Clyde Dam, New Zealand
's third largest hydroelectric dam, is built on the Clutha River
near the town of Clyde
. It is owned and operated by Contact Energy
.
, as well as the scenic Cromwell Gorge
, which was a highlight of the then young but growing New Zealand tourism
industry. Construction also required replacement of a stretch of highway and the closure of the Otago Central Railway beyond Clyde, though materials for the dam would provide significant traffic for the rest of the line which was experiencing a drop in freight tonnage. To mitigate these problems, the Kirk Labour government decided a low dam should be built at Clyde. This decision was overturned by the following National government, who preferred a high dam.
There was also debate about whether the dam was needed. National's support for a controversial aluminium smelter at Aramoana
, another of Prime Minister
Sir Robert Muldoon
's Think Big
projects of the late 1970s and early 1980s, was one justification propounded for the dam. An initial grant of water rights for the dam was overturned by the High Court following an appeal by landowners. National overturned this decision, after bargaining for the support of Social Credit
(who had initially opposed a high dam), in the Clutha Development (Clyde Dam) Empowering Act 1982. The Act was later repealed by the following National government on 1 October 1991, when it was superseded by the Resource Management Act 1991.
The dam was constructed between 1982 and 1993. Filling it was done in four controlled stages beginning in April 1992, and completed the following year, creating Lake Dunstan
. The power station has a capacity of four 120 MW francis turbine
s (for a total of 480 MW), but is only allowed to run 432 MW due to resource consent conditions. The dam is built such that two further penstocks and turbines can be installed, but if they were installed there will not be enough water to keep them running.
During construction, the adjacent rock was discovered to be microfractured, because of an earthquake
fault running underneath the dam site. The dam was redesigned, losing a sluice channel and cutting its generation capacity from 612 MW to 432 MW. A slip joint was built into the dam to accommodate 1-2 metres of potential ground movement, and a large amount of slurry cement
was pumped into the rock to stop water leaks. This additional work was one reason for a major project cost over-run, which made the dam the most expensive in New Zealand. The other areas of over-run were due to stabilisation of landslides in the Cromwell Gorge. There are over 18 km of tunnels throughout the gorge for draining purposes. Because of all this extra work it overran the budget by nearly an extra 50% and delayed the filling of Lake Dunstan by a few years.
Maintenance workers accidentally activated fire alarms in the dam on 15 December 2008. The alarms triggered the release of a large bank of cylinders at the generators, flooding the equipment with the gas. Extractor fans to clear the then activated, and firefighters with breathing apparatus and gas detectors checked through the dam to ensure it had cleared.
.
New Zealand
New Zealand is an island country in the south-western Pacific Ocean comprising two main landmasses and numerous smaller islands. The country is situated some east of Australia across the Tasman Sea, and roughly south of the Pacific island nations of New Caledonia, Fiji, and Tonga...
's third largest hydroelectric dam, is built on the Clutha River
Clutha River
The Clutha River / Mata-Au is the second longest river in New Zealand flowing south-southeast through Central and South Otago from Lake Wanaka in the Southern Alps to the Pacific Ocean, south west of Dunedin. It is the highest volume river in New Zealand, and the swiftest, with a catchment of ,...
near the town of Clyde
Clyde, New Zealand
Clyde is a small town in Central Otago, New Zealand with a population of 918 in 2006. It is located on the Clutha River, between Cromwell and Alexandra....
. It is owned and operated by Contact Energy
Contact Energy
Contact Energy Limited is a New Zealand electricity generator, natural gas wholesaler and electricity, natural gas, and LPG retailer.The company is the second-largest electricity generator in New Zealand , generating 24 percent of New Zealand's electricity in the year ending 31 December 2009, and...
.
History
There was considerable controversy when the dam was planned because it would flood many houses and orchards upstream at CromwellCromwell, New Zealand
Cromwell is a town in Central Otago in the Otago region of New Zealand.It is situated between State Highway 6 and State Highway 8 leading to the Lindis Pass, 75 km northeast, and Alexandra, 33 km south. The road to Alexandra winds through the Cromwell Gorge...
, as well as the scenic Cromwell Gorge
Cromwell Gorge
The Cromwell Gorge is a deep gorge on the Clutha River in the Otago region of New Zealand's South Island. It stretches for 20 km south of the town of Cromwell towards Alexandra....
, which was a highlight of the then young but growing New Zealand tourism
Tourism
Tourism is travel for recreational, leisure or business purposes. The World Tourism Organization defines tourists as people "traveling to and staying in places outside their usual environment for not more than one consecutive year for leisure, business and other purposes".Tourism has become a...
industry. Construction also required replacement of a stretch of highway and the closure of the Otago Central Railway beyond Clyde, though materials for the dam would provide significant traffic for the rest of the line which was experiencing a drop in freight tonnage. To mitigate these problems, the Kirk Labour government decided a low dam should be built at Clyde. This decision was overturned by the following National government, who preferred a high dam.
There was also debate about whether the dam was needed. National's support for a controversial aluminium smelter at Aramoana
Aramoana
Aramoana, also known as "The Spit" to locals, is a small coastal settlement, 27 kilometres north of Dunedin city, in the South Island of New Zealand. The settlement's permanent population in 2001 Census was 261. Supplementing this are seasonal visitors from the city who occupy cribs...
, another of Prime Minister
Prime Minister of New Zealand
The Prime Minister of New Zealand is New Zealand's head of government consequent on being the leader of the party or coalition with majority support in the Parliament of New Zealand...
Sir Robert Muldoon
Robert Muldoon
Sir Robert David "Rob" Muldoon, GCMG, CH served as the 31st Prime Minister of New Zealand from 1975 to 1984, as leader of the governing National Party. Muldoon had been a prominent member of the National party and MP for the Tamaki electorate for some years prior to becoming leader of the party...
's Think Big
Think Big
The New Zealand Prime Minister Robert Muldoon and his New Zealand National Party government in the early 1980s sponsored Think Big as an interventionist state economic strategy. The Think Big schemes saw the government borrow heavily overseas, running up a large external deficit, and using the...
projects of the late 1970s and early 1980s, was one justification propounded for the dam. An initial grant of water rights for the dam was overturned by the High Court following an appeal by landowners. National overturned this decision, after bargaining for the support of Social Credit
Social Credit Party (New Zealand)
The New Zealand Social Credit Party was a political party which served as the country's "third party" from the 1950s through into the 1980s. The party held a number of seats in the New Zealand Parliament, although never more than two at a time...
(who had initially opposed a high dam), in the Clutha Development (Clyde Dam) Empowering Act 1982. The Act was later repealed by the following National government on 1 October 1991, when it was superseded by the Resource Management Act 1991.
The dam was constructed between 1982 and 1993. Filling it was done in four controlled stages beginning in April 1992, and completed the following year, creating Lake Dunstan
Lake Dunstan
Lake Dunstan is a man-made lake and reservoir in the South Island of New Zealand.The lake was formed on the Clutha River as a result of the construction of the Clyde Dam, filling in four controlled stages beginning in April 1992 and completed the next year...
. The power station has a capacity of four 120 MW francis turbine
Francis turbine
The Francis turbine is a type of water turbine that was developed by James B. Francis in Lowell, Massachusetts. It is an inward-flow reaction turbine that combines radial and axial flow concepts....
s (for a total of 480 MW), but is only allowed to run 432 MW due to resource consent conditions. The dam is built such that two further penstocks and turbines can be installed, but if they were installed there will not be enough water to keep them running.
During construction, the adjacent rock was discovered to be microfractured, because of an earthquake
Earthquake
An earthquake is the result of a sudden release of energy in the Earth's crust that creates seismic waves. The seismicity, seismism or seismic activity of an area refers to the frequency, type and size of earthquakes experienced over a period of time...
fault running underneath the dam site. The dam was redesigned, losing a sluice channel and cutting its generation capacity from 612 MW to 432 MW. A slip joint was built into the dam to accommodate 1-2 metres of potential ground movement, and a large amount of slurry cement
Cement
In the most general sense of the word, a cement is a binder, a substance that sets and hardens independently, and can bind other materials together. The word "cement" traces to the Romans, who used the term opus caementicium to describe masonry resembling modern concrete that was made from crushed...
was pumped into the rock to stop water leaks. This additional work was one reason for a major project cost over-run, which made the dam the most expensive in New Zealand. The other areas of over-run were due to stabilisation of landslides in the Cromwell Gorge. There are over 18 km of tunnels throughout the gorge for draining purposes. Because of all this extra work it overran the budget by nearly an extra 50% and delayed the filling of Lake Dunstan by a few years.
Maintenance workers accidentally activated fire alarms in the dam on 15 December 2008. The alarms triggered the release of a large bank of cylinders at the generators, flooding the equipment with the gas. Extractor fans to clear the then activated, and firefighters with breathing apparatus and gas detectors checked through the dam to ensure it had cleared.
Trivia
The Clyde Dam, while still under construction, was used for on-location filming in the 1985 movie Shaker RunShaker Run
Shaker Run is a 1985 Action film by director Bruce Morrison, starring Cliff Robertson, Leif Garrett, and Lisa Harrow. It follows two stunt drivers on the run from secret police in the South Island of New Zealand with a Doctor , carrying a virus for the CIA.-External links:*...
.