Lake Burragorang

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Not to be confused with Warragamba Dam.
Lake Burragorang
Lake burragorang aerial.jpg
from the air (April 2006)
Coordinates 34°0′S 150°26′E / 34.000°S 150.433°E / -34.000; 150.433Coordinates: 34°0′S 150°26′E / 34.000°S 150.433°E / -34.000; 150.433
Type Man-made water supply dammed reservoir
Primary inflows Coxs, Kowmung, Nattai, Wingecarribee, Wollondilly and Warragamba rivers
Primary outflows Warragamba River
Catchment area 9,051 km2 (3,495 sq mi)
Basin countries Australia
Max. length 52 km (32 mi)
Surface area 75 km2 (29 sq mi)
Max. depth 105 m (344 ft)
Water volume 2,031 GL (4.47×1011 imp gal; 5.37×1011 US gal)
Shore length1 354 km (220 mi)
Surface elevation 110 m (360 ft)
1 Shore length is not a well-defined measure.

Lake Burragorang is an Australian man-made water supply dammed reservoir.

Lake Burragorang is impounded by Warragamba Dam and is located in the lower Blue Mountains of New South Wales, within the Greater Blue Mountains Area World Heritage Site. The 2,031-gigalitre (4.47×1011 imp gal; 5.37×1011 US gal) reservoir collects water from the converged flows of the Coxs, Kowmung, Nattai, Wingecarribee, Wollondilly, and Warragamba rivers and their associated tributaries. The reservoir is the major water storage for greater metropolitan Sydney, and its dam wall is located approximately 60 kilometres (37 mi) southwest of the Sydney central business district.

Pre-lake history[edit]

Before the construction of the dam, Burragorang Valley had been inhabited by white settlers since the 19th century. A number of farming towns (including the town of Burragorang) and coal mines were located in the area. All of these are now underwater.[1]

Capacity[edit]

The reservoir's usable capacity is 2,027 gigalitres (4.46×1011 imp gal; 5.35×1011 US gal). Prior to April 2006, the usable capacity was 1,857 gigalitres (4.08×1011 imp gal; 4.91×1011 US gal), before the Deep Water Storage Recovery project was completed. There are fears,[by whom?] however, that population pressures may stretch the reservoir's ability to furnish Sydney residents with needed water well into the 21st century.[2] The city's population is rising by about 50,000 every year,[citation needed] and water restrictions were imposed late in 2003; a serious drought would complicate matters.

There have been times when the reservoir has been seriously depleted. Since it was last full in 1998 the Warragamba Dam catchment area experienced extremely low rainfall, and on 8 February 2007 the lake recorded an all time low of 32.5% of capacity, although this had returned to 60% by late 2008.[3] To prevent any chance of water supply failure, the NSW Government authorised the construction and operation of the Sydney Desalination Plant to augment Sydney's water supply.

As of 1 March 2012 the dam level was at 94.6% and rising. It was predicted to overflow within a day.[4]

In the upper left corner of the view (at right) looking roughly southeastwards are Sydney's western suburbs. A crooked corridor of development may also be seen leading through the forested mountains to Sydney suburbs of Katoomba and Blackheath (near the centre) and beyond.

Public access[edit]

Lake Burragorang from space, November 1985

Lake Burragorang is surrounded by a 3 kilometres (1.9 mi) wide exclusion zone to protect the integrity of the water supply; access into this zone is restricted. There are two access corridors for bushwalkers: Mount Mouin to Mount Cookem and Belloon Pass to Yerranderie.[5] Limited public vehicle access is allowed on fire trail W4 from Sheahys Creek to Yerranderie.

Power station[edit]

A hydroelectric power station at Warragamba Dam begins operating once the level in the reservoir reaches to within 1 metre (3 ft 3 in) of full capacity. Its output is 50 megawatts (67,000 hp),[6] but the dam water level has not been high enough for it to operate since 1998.

Statistical overview[edit]

Key reservoir statistics[7]
Available storage (when full) 2,027 gigalitres (4.46×1011 imp gal; 5.35×1011 US gal)
Total capacity (when full) 2,031 gigalitres (4.47×1011 imp gal; 5.37×1011 US gal)
Surface area 75 square kilometres (29 sq mi)
Length of lake 52 kilometres (32 mi)
Length of foreshores 354 kilometres (220 mi)
Deepest point 105 metres (344 ft)
Catchment area 9,051 square kilometres (3,495 sq mi)
Average annual rainfall 840 millimetres (33 in)

See also[edit]

References[edit]

  1. ^ "Natural Attractions - Burragorang Valley, Lake Burragorang" stonequarry.com.au
  2. ^ "Coxs River Carrying Capacity" PDF
  3. ^ "Weekly storage and supply report: 4 December 2008". Sydney Catchment Authority. 4 December 2008. Retrieved 4 December 2008. 
  4. ^ "Warragamba Dam to spill Friday morning: BoM". ABC News (Australia). 2 March 2012. Retrieved 2 March 2012. 
  5. ^ Paton, Neil (2004). Sydney and Blue Mountains Bushwalks. Sydney: Kangaroo Press. p. 339. 
  6. ^ "Hydro Power Stations: Warragamba". Generation Portfolio. Eraring Energy. Retrieved 3 March 2012. 
  7. ^ "Warragamba Dam facts". Major SCA dams: Warragamba Dam. Sydney Catchment Authority. 8 March 2011. Retrieved 6 April 2013. 

External links[edit]