Crotty Dam | |
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Location of the Crotty Dam in Tasmania | |
Country | Australia |
Location | West Coast Tasmania |
Coordinates | 42°09′35″S145°37′00″E / 42.15972°S 145.61667°E Coordinates: 42°09′35″S145°37′00″E / 42.15972°S 145.61667°E |
Purpose | Power |
Status | Operational |
Opening date | 1991 |
Owner(s) | Hydro Tasmania |
Dam and spillways | |
Type of dam | Embankment dam |
Impounds | King River |
Height | 83 metres (272 ft) |
Length | 245 metres (804 ft) |
Width (crest) | 300 millimetres (12 in) |
Dam volume | 770×10 3 m3 (27×10 6 cu ft) |
Spillways | 1 |
Spillway type | Controlled and uncontrolled |
Spillway capacity |
|
Reservoir | |
Creates | Lake Burbury |
Total capacity | 1,081,420 ML (38,190×10 6 cu ft) |
Active capacity | 1,065,000 ML (37,600×10 6 cu ft) |
Catchment area | 559 km2 (216 sq mi) |
Surface area | 53,250×10 3 m2 (573.2×10 6 sq ft) |
John Butters Power Station | |
Coordinates | 42°09′21″S145°32′04″E / 42.15583°S 145.53444°E |
Operator(s) | Hydro Tasmania |
Commission date | 1992 |
Type | Conventional |
Hydraulic head | 184 metres (604 ft) |
Turbines | 1 x 144 MW (193,000 hp) Fuji Francis turbine |
Installed capacity | 144 megawatts (193,000 hp) |
Capacity factor | 0.9 |
Annual generation | 576 gigawatt-hours (2,070 TJ) |
Website hydro |
The Crotty Dam, also known during construction as the King Dam, [1] or the King River Dam on initial approval, [2] is a rockfill embankment dam with a controlled and uncontrolled spillway across the King River, between Mount Jukes and Mount Huxley, located in Western Tasmania, Australia.
The impounded reservoir is called Lake Burbury.
The dam was constructed in 1991 as part of the King River Power Development Scheme, by the Hydro Electric Corporation (TAS) for the purpose of generating hydro-electric power via the John Butters Power Station located 8 kilometres (5.0 mi) below the dam wall. [3]
The Crotty Dam, together with the Darwin Dam, are two major dams that form the headwaters for the King River Hydroelectric Power Development. The dam is located in the upper reaches of the King River gorge where the river breaks through the West Coast Range. It captures the high rainfall in the catchment of the King River and allows diversion of water through a tunnel to the John Butters Power Station downstream of the dam.
The Crotty Dam wall, constructed with 770 thousand cubic metres (27×10 6 cu ft) of concrete faced rock and gravel fill core, is 83 metres (272 ft) high and 245 metres (804 ft) long. At 100% capacity the dam wall holds back 1,081,420 megalitres (38,190×10 6 cu ft) (43,000×106 cu ft) of water. The surface area of Lake Burbury is 53,250 hectares (131,600 acres) and the catchment area is 559 square kilometres (216 sq mi). The single uncontrolled and controlled spillway is capable of discharging 435 cubic metres per second (15,400 cu ft/s). [4]
A unique feature of the dam is its spillway. The spillway is located on the embankment, rather than on one of the rock abutments. This had never been successfully attempted before in the design of dams of any significant height, due to problems in making allowance for embankment settlements. In the case of Crotty Dam, the embankment was partly composed of well graded gravels, and thus a very high modulus of embankment deformation was achieved. The high modulus limits embankment settlements. Additionally, the spillway was designed to articulate in order to accommodate any settlement that did occur.
The spillway is designed to allow sufficient time for a large jet flow valve located in the diversion tunnel to be opened so that larger floods can be safely handled.
The spillway designers, Sergio Giudici, also the chief engineer on the Gordon Dam, Frank Kinstler, Steven Li, Tony Morse and Graeme Maher were acknowledged within the engineering community because the spillway was the first known to "provide for articulation of the spillway structure so that movements in its foundations could occur without damage to the overlying structure". [5]
The water from Lake Burbury is conveyed through a 7-kilometre (4.3 mi) long unlined tunnel that runs through Mount Jukes to the John Butters Power Station, which is located on the King River downstream of the dam and King River gorge, near the confluence with the Queen River. [6]
The dam was constructed in the 1980s following the abandonment of the Gordon-below-Franklin power development scheme, part of the Franklin Dam. The Crotty Dam was commissioned in 1991, with the King River Power development being completed by 1992. [7]
The dam is named in honour of James Crotty who founded the North Mount Lyell Copper Mine at the turn of the 20th century. A ghost town site of the same name Crotty was submerged by the waters of Lake Burbury.
In the 1910s the Mount Lyell Mining and Railway Company had investigated and surveyed a site very close to this dam for a proposed hydro electric scheme. Charles Whitham also wrote of the inevitability of the dam in 1927 and even proposed "Lake Dorothy" as a name for the reservoir.
In 2001, Engineers Australia selected Crotty Dam as one of the 25 dams with the greatest Australian heritage value. [5] It was awarded a Historic Engineering Marker as part of the Engineering Heritage Recognition Program. [8]
Dartmouth Dam is a large rock-fill embankment dam with an uncontrolled chute spillway across the Mitta Mitta, Gibbo, and Dart rivers, the Morass Creek and a number of small tributaries. The dam is located near Mount Bogong in the north-east of the Australian state of Victoria. The dam's purpose includes irrigation, the generation of hydro-electric power, water supply and conservation. The impounded reservoir is called Dartmouth Reservoir, sometimes called Lake Dartmouth. The Dartmouth Power Station, a hydro-electric power station that generates power to the national grid, is located near the dam wall.
The King River is a major perennial river in the West Coast region of Tasmania, Australia.
The Lake Margaret Power Stations comprise two hydroelectric power stations located in Western Tasmania, Australia. The power stations are part of the King – Yolande Power Scheme and are owned and operated by Hydro Tasmania. Officially the Upper Lake Margaret Power Station, a conventional hydroelectric power station, and the Lower Lake Margaret Power Station, a mini-hydroelectric power station, the stations are generally collectively referred to in the singular format as the Lake Margaret Power Station. The stations are located approximately 2.5 kilometres (1.6 mi) apart.
The West Coast Range is a mountain range located in the West Coast region of Tasmania, Australia.
Lake Margaret is a concrete-faced gravity dam with an uncontrolled spillway across the Yolande River, located on the north side of Mount Sedgwick, in the West Coast Range, West Coast of Tasmania, Australia.
Crotty is a former gazetted townsite that was located in Western Tasmania, Australia. The township was located on the eastern lower slopes of Mount Jukes, below the West Coast Range, and on the southern bank of the King River. The locality had had a former name of King River
The North Mount Lyell Railway was built to operate between the North Mount Lyell mine in West Coast Tasmania and Pillinger in the Kelly Basin of Macquarie Harbour.
Lake Burbury is a man-made water reservoir created by the Crotty Dam inundating the upper King River valley that lies east of the West Coast Range. Discharge from the reservoir feeds the John Butters Hydroelectric Power Station, owned and operated by Hydro Tasmania.
Mount Huxley is a mountain located on the West Coast Range in the West Coast region of Tasmania, Australia. With an elevation of 926 metres (3,038 ft) above sea level, the mountain was named by Charles Gould in 1863 in honour of Professor Thomas Henry Huxley.
Mount Jukes is a mountain located on the Jukes Range, a spur off the West Coast Range, in the West Coast region of Tasmania, Australia.
The Darwin Dam is an offstream earthfill embankment saddle dam without a spillway, located in Western Tasmania, Australia. The impounded reservoir, also formed by Crotty Dam, is called Lake Burbury.
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The Gordon Dam, also known as the Gordon River Dam, is a major gated double curvature concrete arch dam with a controlled spillway across the Gordon River, located in Southwest National Park, Tasmania, Australia. The impounded reservoir is called Lake Gordon.
The Scotts Peak Dam is a rockfill embankment dam without a spillway across the Huon River, located in the South West region of Tasmania, Australia.
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The Edgar Dam is an earthfill embankment saddle dam without a spillway, located offstream in the South West region of Tasmania, Australia.
The Anthony Power Development Scheme, part of the Pieman River power development scheme, was a proposed scheme for damming parts of the upper catchment of the Pieman River in Western Tasmania, Australia.
Rydal Dam is a minor ungated homogeneous earthfill embankment dam with a fuse plug uncontrolled open channel spillway across an off stream storage, located near Rydal in the Central Tablelands region of New South Wales, Australia. The dam's purpose is to provide water storage for Delta power stations at Wallerawang and Mount Piper. The impounded reservoir is also called the Rydal Dam.
The Meander Dam is a concrete gravity dam across the Upper Meander River, located in northern Tasmania, Australia. The impounded reservoir is called Lake Huntsman.
The John Butters Power Station is a conventional hydroelectric power station located in Western Tasmania, Australia. The power station forms part of the King – Yolande River Power Scheme and is owned and operated by Hydro Tasmania.