Lake Benmore
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Lake Benmore Te Ao Marama |
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| Coordinates | 44 ° 24 '54 " S , 170 ° 13' 14" O | ||||||||
| Data on the structure | |||||||||
| Lock type: | Gravity dam | ||||||||
| Construction time: | 1958-1965 | ||||||||
| Height of the barrier structure : | 110 m | ||||||||
| Building volume: | 28 million tons | ||||||||
| Crown length: | 823 m earth dam 122 m concrete structure |
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| Crown width: | 10.6 | ||||||||
| Base width: | 490 m | ||||||||
| Power plant output: | 540 MW | ||||||||
| Operator: | Meridian Energy | ||||||||
| Data on the reservoir | |||||||||
| Altitude (at congestion destination ) | 355.25 m - 361.45 m | ||||||||
| Water surface | 74.5 | ||||||||
| Reservoir length | 18 km u. 28 km | ||||||||
| Reservoir width | 160 m - 4.9 km | ||||||||
| Maximum depth | 91 m | ||||||||
| Total storage space : | 2.04 billion m 3 | ||||||||
| Catchment area | 8th 500 km² | ||||||||
| Particularities: |
largest artificial lake in New Zealand |
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The Lake Benmore ( Māori Te Ao Marama ) is a reservoir in the region Canterbury on the South Island of New Zealand . It is one of seven reservoirs of the Waitaki Hydro Scheme (hydropower project), which has a water catchment area of almost 97 km 2 .
geography
The multi-armed reservoir is located at a height of 362 m around 75 km west of Timaru and around 85 km northwest of Oamaru between the reservoirs Lake Aviemore in the southeast and Lake Pukaki in the north. Its two arms are 18 km and 28 km in length, the north-facing one being the longer of the two. The western arm is part of the Waitaki District and half of the northern arm is part of the Waitaki District and Mackenzie District , whereas a small southeastern part is assigned to the Waimate District and there the lake has a maximum depth of 91 m according to hydrographic surveys . Other sources give the maximum depth of 96 m.
The Lake Benmore , with an area of 74.5 km 2 and a shoreline length of 116 km, the largest lake created by people in New Zealand and measures for comparison of size 1.5 times the water volume of the Wellington Harbor .
Its tributaries are from north to south and from west to east lists the rivers Ohau River , Twizel River , Tekapo River , Stony River , Ahuriri River , Otamatatapaio River and the Pukaki River , as a tributary of the Tekapo River and numerous creeks and streams from the surrounding mountains. The reservoir drains via the adjacent Lake Aviemore . The damming of the lake has resulted in the formation of a number of islands, of which Whanau Island , Junction Island , Black Jacks Island and Goose Neck Island are the largest.
The water catchment area of Lake Benmore covers an area of around 8500 km 2 with an average annual water discharge of 323 m 3 / sec. The dammed up water of the lake fills a volume of 2.04 billion m 3 .
The reservoir target of the reservoir was set at 355.25 m to 361.45 m.
history
In 1958, the New Zealand government began realizing the dam project to impound the lake and use it to generate electricity. For the multi-year project and the delayed Lake Aviemore dam project , the government had the Otematata settlement built for the construction workers in 1958 , which at its peak in 1963 gave a home to over 4,000 residents. Many houses were later sold as holiday accommodation. In 1962, 1240 construction workers and 160 heavy construction machinery were employed on the dam on Lake Benmore . After the completion of the Benmore dam and power station, work began on damming the lake, which was completed in December 1964. The first generators were put into operation in January 1965 and three months later, on May 15, 1965, the power plant was officially inaugurated by the then Prime Minister of New Zealand, Keith Holyoake . Originally built for the New Zealand Electricity Department , the power plant and dam has been owned by the current operator Meridian Energy since 1999 .
Barrier structure
The 110 m high and at its base 490 m wide barrier structure is designed as a gravity dam and extends over an 823 m long earth dam and a 122 m long concrete barrier structure. With 12 million m 3 of soil and almost 400,000 m 3 of concrete, it is the largest structure of its kind in New Zealand. The structure has a north-south orientation with an arc of about 30 degrees in a north-westerly direction from the north end. There are also the six penstocks that lead to the power plant below the dam. The flood relief is carried out at the southern end of the dam.
power plant
With an installed capacity of 540 MW, the Benmore power plant is the second largest power plant in New Zealand after the Manapouri power plant . Its annual output, which is provided by six 90 MW generators, adds up to 2200 GWh. From 2008 to 2010, all six turbines were overhauled for a sum of $ 67 million NZ , which with the same water throughput, an efficiency increase of 5% and an annual output of 70 GWh corresponds.
tourism
The reservoir is used for swimming, water skiing and boating as well as for trout fishing. There is a campsite in the northern part of the lake.
Water pollution
In 2013, the introduced waterweed (lagarosiphon) spread in the lake , which was combated by herbicides and residents and visitors to the lake were made public.
literature
- OT Jones : Design of Benmore Earth Dam . In: NZ Engineering . January 15, 1965, p. 13–23 (English, online [PDF; 698 kB ; accessed on January 15, 2020]).
- T. Story : Earthmoving for Benmore Earth Dam . In: NZ Engineering . January 15, 1965, p. 29–35 (English, online [PDF; 630 kB ; accessed on January 15, 2020]).
- RD Adams : Statistical studies of earthquakes associated with Lake Benmore, New Zealand . In: Engineering Geology . Vol. 8, Issue 1-2 , August 1974, pp. 155-169 , doi : 10.1016 / 0013-7952 (74) 90022-2 (English).
- RA Pickrill, J. Irwin : Circulation and sedimentation in Lake Benmore, New Zealand . In: New Zealand Journal of Geology and Geophysics . Vol. 29, Issue 1 , 1986, ISSN 0028-8306 , pp. 83-97 , doi : 10.1080 / 00288306.1986.10427525 (English).
- Martin Reyners : Reservoir-induced seismicity at Lake Pukaki, New Zealand . In: Geophysical Journal . Vol. 93 , 1988, pp. 127–135 (English, online [PDF; 1.4 MB ; accessed on January 15, 2020]).
Web links
Individual evidence
- ^ Ngai Tahu Claims Settlement Act 1998 . In: Legislation New Zealand . Parliamentary Counsel Office , 1998, accessed January 15, 2020 .
- ^ Upper and Lower Waitaki Catchment . Land Air Water Aotearoa , accessed January 15, 2020 .
- ↑ a b Topo maps . Land Information New Zealand , accessed January 12, 2020 .
- ↑ Coordinates and longitudes were determined using Goggle Earth Pro Version 7.3.2.5776 on January 15, 2020
- ↑ Waitaki Disctrict Council Ward Area . (JPG; 943 kB) Waitaki Disctrict Council , archived from the original on October 14, 2008 ; accessed on April 25, 2019 (English, original website no longer available).
- ↑ Pickrill, Irwin : Circulation and sedimentation in Lake Benmore, New Zealand . 1986, p. 83 .
- ↑ Reyners : reservoir-induced seismicity at Lake Pukaki, New Zealand . 1988, p. 127 .
- ↑ a b c Discover the Waitaki Hydro Scheme . (PDF; 1.9 MB) Meridian Energy , November 2008, archived from the original on February 17, 2011 ; accessed on January 15, 2020 (English, original website no longer available).
- ↑ Pickrill, Irwin : Circulation and sedimentation in Lake Benmore, New Zealand . 1986, p. 86 .
- ^ Adams : Statistical studies of earthquakes associated with Lake Benmore, New Zealand . 1974, p. Abstract .
- ^ Lake levels - Lake Aviemore lake levels . Meridian Energy , accessed January 15, 2020 .
- ^ A b Matthew Wright : Engineering - Benmore dam . In: Te Ara - the Encyclopedia of New Zealand . Ministry for Culture & Heritage , March 11, 2010, accessed January 15, 2020 .
- ↑ Benmore hydro station . Meridian Energy , accessed January 15, 2020 .
- ↑ a b c David Bruce : Benmore gets more with first full rebuild . In: Otago Daily Times . Allied Press Limited , October 30, 2008, accessed January 15, 2020 .
- ^ Story : Earthmoving for Benmore Earth Dam . 1965, p. 29 .
- ^ Jones : Design of Benmore Earth Dam . 1965, p. 13 .
- ↑ Veronika Meduna : Lake Benmore hydroelectric dam . In: Te Ara - the Encyclopedia of New Zealand . Ministry for Culture & Heritage , June 12, 2006, accessed January 15, 2020 .
- ^ Lake Benmore - Navigation Safety Bylaws . (PDF 426 kB) Environment Canterbury , archived from the original on May 22, 2010 ; accessed on August 26, 2014 (English, original website no longer available).
- ^ Notice of Weed Spraying in Lake Benmore . Land Information New Zealand , August 22, 2013, accessed January 15, 2016 .
