Clyde Dam

from Wikipedia, the free encyclopedia
Clyde Dam
Clyde Dam with the Clyde Power Station
Clyde Dam with the Clyde Power Station
Location: Central Otago District , Otago Region, South Island , New Zealand
Tributaries: Clutha River , Kawarau River and numerous Streams and Creeks (brooks)
Drain: Clutha River
Larger places on the shore: Clyde , Cromwell
Major cities nearby: Alexandra
Clyde Dam (New Zealand)
Clyde Dam
Coordinates 45 ° 10 '45 "  S , 169 ° 18' 23"  O Coordinates: 45 ° 10 '45 "  S , 169 ° 18' 23"  O
Data on the structure
Lock type: Gravity dam
Construction time: 1979-1992
Height above valley floor: 60 m
Height above foundation level : 105 m
Height above the river bed : 60 m
Height of the structure crown: 200  m
Building volume: 1 000 000  m³
Crown length: 490 m
Crown width: 10 m
Base width: 70 m
Slope slope on the air side : 1: 0.125
Slope slope on the water side : 1: 0.666
Power plant output: 432 MW
Operator: Contact Energy
Data on the reservoir
Altitude (at congestion destination ) 194.5  m
Water surface 26.4 km²dep1
Reservoir length 34.5 km
Reservoir width 1.7 km
Maximum depth 60 m
Total storage space : 430 000 000  m³
Catchment area 12 000  km²
Design flood : 5 800  m³ / s
The water level fluctuates between 193.5 m and 194.5 m and the flood level is reached at 195.1 m. The above data are taken from the Clyde Dam - Fact Sheet and an information board at the lookout point over the lake near Cromwell.
Clyde Dam Under Construction.jpg
The dam under construction (around 1986)
Template: Infobox reservoir / maintenance

The Clyde Dam is a gravity dam in the Central Otago District of the Otago region on the South Island of New Zealand . It was built between 1979 and 1993 to dam the Clutha River and the Kawarau River to generate electricity to Lake Dunstan .

geography

The dam is located in the small town of Clyde , around 10 km northwest of Alexandra in the Otago highlands . The Clyde Power Station hydroelectric power station is located directly below the dam.

history

prehistory

During the planning of the dam, there was considerable controversy among the population as it was foreseeable that the reservoir would flood numerous houses and orchards further upstream at Cromwell .

The construction work also affected the Cromwell Gorge , a narrow section of the Clutha River southeast of Cromwell , scenic and popular with tourists, which would partially sink in the floods, and the New Zealand State Highway 6 , which would have had to be completely rebuilt on the section . In addition, security measures in the landscape paid off , which alone were estimated at NZ $ 337 million . The former section of the Otago Central Railway beyond the town of Clyde would have had to be closed and an expensive material transport to the construction site with the burdens for the population would have been the result.

In order to be able to reduce the negative consequences of the construction project and to gain greater acceptance among the population, the Labor government at the time under Norman Kirk decided to build a lower dam near Clyde . This decision was reversed by the subsequent government of the National Party , which preferred a high dam. There were also discussions about whether the dam was even necessary. The National Party's support for a controversial aluminum plant at Aramoana , another Think Big project by Prime Minister Robert Muldoon of the late 1970s and early 1980s, was one of the reasons the dam was eventually built, as a result of which citizen interests were partially undermined by special laws, such as the Example when the already granted water rights for electricity generation were declared invalid by the Supreme Court due to an appeal by landowners. National overturned the court decision by a special law. After negotiations with the Social Credit Party , which had originally rejected the dam, construction was finally legalized with their help through the Clutha Development (Clyde Dam) Empowering Act 1982 .

The construction

Construction work on the dam began in 1979. During the work, microcracks were found in the surrounding rock, which resulted from a geological fault under the dam. The construction of the dam had to be revised as a result. A turbine shaft was eliminated and the power generation capacity was reduced from the planned 612 MW to 432 MW. In addition, an expansion joint had to be planned in the structure, which allowed the dam to be offset by two meters in the horizontal direction and one meter in the vertical direction in the event of tectonic ground movements.

Large quantities of liquid concrete were injected into the rock to stabilize it in order to seal leaks. These additional expenses resulted in a significant overrun of schedule and costs, making the dam the most expensive in the country. Furthermore, landslides and the possibility of further landslides due to a possible rise in the groundwater level in the area of Cromwell Gorge led to additional delays in the overall project, as stabilization measures were necessary on the slopes. The measures alone cost NZ $ 936 million  .

After the dam was completed, the reservoir was filled in four controlled stages from April 1992 to 1993.

Data of the dam

The Clyde Dam measures 60 m from the bottom of the valley to the crown, including the foundation 105 m. The dam stretches over a length of 490 m through the valley, is 70 m thick at the base and tapers up to a wall thickness of 10 m. The gradient ratio of the dam wall on the lake side is 1: 0.666 and on the power station side 1: 0.125. A total of around 1 million m³ of concrete was used. Four pressure pipes with a diameter of 7.8 m each, embedded in the dam, carry the dammed water with a maximum flow rate of around 1000 m³ / sec. to the turbines of the power plant. For a possible capacity expansion, space was reserved for two more possible lines in the dam.

At high tide, four radial, 14.3 m high and 10 m wide gates ensure a maximum possible flow of 4600 m³ / sec. Another lock gate, with a height of 9.6 m and a width of 6 m, allows a further discharge of 1430 m³ / sec. The largest flood to date came in November 1999 to a maximum flow of around 3500 m³ / sec.

A pipeline leading from the dam supplies the Earnscleugh plain south of the dam with water for irrigation with a throughput of 2.4 m³ / sec. The west of the Clutha River flowing towards the Fraser River is over the line with 1 m³ / sec. additional water supplied.

The power plant

The dam's hydropower plant, operated by Contact Energy , has four 108 MW Francis turbines with a maximum output of 432 MW.

sightseeing

In April 2017, the dam and the power plant could be viewed from the inside for the first time by the public.

Trivia

During construction, the Clyde Dam was used as a film set in July 1984 for some scenes from the film Shaker Run .

Panoramic photos

The Clyde Dam with the
Clyde Power Station below
Lake Dunstan with the Clyde Dam (left)

See also

literature

  • John E. Martin : People, Politics and Power Stations . Electric power generation in New Zealand, 1880–1990 . Ed .: Electricity Corporation of New Zealand . Wellington 1991, ISBN 0-908912-16-1 (English).
  • Trevor Reeves, Judith Wolfe : An Abuse of Power: The Story of the Clyde Dam . Square One Pres , Dunedin 1994, ISBN 0-908562-12-8 (English).
  • Marion Sheridan : Dam Dwellers - End of an Era . Sheridan Press , Twizel 1995, ISBN 0-473-03402-6 (English).
  • Aynsley John Kellow : Transforming power: the politics of electricity planning . Cambridge University Press , 1996, ISBN 978-0-521-47122-0 (English).

Web links

Commons : Clyde Dam  - collection of images, videos and audio files

Individual evidence

  1. a b c d Clyde Dam - Fact Sheet . Contact Energy , accessed June 21, 2018 .
  2. ↑ Information board at the viewpoint on the lake near Cromwell, photographed and accessed on February 12, 2017
  3. Topo maps . Land Information New Zealand , accessed June 21, 2018 .
  4. a b Shane Gilchrist : Reflections on Lake Dunstan . Otago Daily Times , January 2, 2010, accessed June 21, 2018 .
  5. ^ Dai Redshaw : Sustainable Energy . In: New Zealand Science Monthly . March 1997, archived from the original on November 9, 2007 ; accessed on November 8, 2010 (English, original website no longer available).
  6. a b c Kellow : Transforming power: the politics of electricity planning . 1996.
  7. Key Points for Rational Design for Civil-Infrastructures near Seismic Faults Reflecting Soil-Structure Interaction Features . Japan Society for Promoting Science , 2007, Chapter 7.6 - Clyde Dam in New Zealand, after Hatton et al. (1987) and Hatton et al. (1991) , p.  96–97 (English, online [PDF; 3.3 MB ; accessed on June 21, 2018]).
  8. Eileen McSaveney : Earthquakes - Building for earthquake resistance . In: Te Ara - the Encyclopedia of New Zealand . Ministry for Culture & Heritage , August 1, 2017, accessed June 21, 2018 .
  9. Michael J. Crozier : Landslides - People and landslides . In: Te Ara - the Encyclopedia of New Zealand . Ministry for Culture & Heritage , June 12, 2006, accessed June 21, 2018 .
  10. Vicki Hyde : Slip Sliding Away . In: New Zealand Science Monthly . November 1990, archived from the original on October 31, 2007 ; accessed on June 21, 2018 (English, original website no longer available).
  11. ^ Contact Hydro . (PDF 1.8 MB) Contact Energy , p. 8 , archived from the original on October 5, 2018 ; accessed on June 21, 2018 (English, original website no longer available).
  12. Dave Goosselink : Public gets first look inside the Clyde Dam . In: NewsHub . Media Works TV , April 21, 2017, accessed June 21, 2018 .
  13. ^ Shaker Run (1985) - Filming & Production . In: IMDb.com . Retrieved June 21, 2018 .