Lake Burragorang

Lake Burragorang ; Warragamba Dam
	Lake Burragorang (April 2006)
Location:	East of the Australian state of New South Wales
Tributaries:	Kedumba River , Cedar Creek, Coxs River , Kowmung River , Black Hollow Creek, Green Wattle Creek, Lacys Creek, Tonalli River , Wollondilly River , Nattai River , Monkey Creek
Drain:	Warragamba River → Nepean River → Hawkesbury River → Tasman Sea
Larger cities on the shore:	Nattai, Warragamba
Major cities nearby:	Yarranderie, Katoomba
	New South Wales , Australia
Coordinates	33 ° 53 '0 " S , 150 ° 35' 44" O Coordinates: 33 ° 53 '0 " S , 150 ° 35' 44" O
	Data on the structure
Construction time:	1946-1960
Height of the barrier structure :	142 m
Building volume:	1.2 million m³
Crown length:	351 m
Crown width:	8.5 m
Base width:	104 m
Radius of curvature :	0 m
Power plant output:	50 MW
	Data on the reservoir
Water surface	75 km²
Reservoir length	52 km
Storage space	2027 million m³
Total storage space :	2031 million m³
Catchment area	9051 km²
	Warragamba Dam

The Lake Burragorang is a large reservoir in the east of the Australian state of New South Wales . It was created by the construction of the Warragamba dam on the river of the same name near the small town of Warragamba about 65 km west of Sydney . There, the waters of the Kedumba River , the Coxs River , the Kowmung River , the Wollondilly River , the Tonalli River and the Nattai River are dammed, all of which previously flowed into the Coxs River and the Warragamba River. The lake serves as the most important drinking water reservoir for the Sydney region. It is located in the Blue Mountains and is surrounded by several national parks and state conservation areas, such as Blue Mountains National Park , Kanangra Boyd National Park , Nattai National Park , Burragorang State Recreation Park , Nattai State Recreation Park, and Yerranderie State Recreation Park surround.

Burragorang Valley

The Warragamba River flows through a narrow gorge that is 300–600 m wide and 100 m deep. At the upper end this gorge opened into a wide valley, the Burragorang Valley . Before the dam was built, the valley had been inhabited by white settlers since the 19th century. A number of rural small towns such as B. Burragorang , and coal mines were in the valley. Today they are all flooded.

Dam and reservoir

Plans and construction

In 1845 the explorer Paul Edmund de Strzelecki became aware of the Warragamba River as a possible source of water for Sydney. In 1867, supporters first suggested building a dam. Between 1867 and 1946 there were various proposals for dam construction before the current location was chosen. In 1940 a weir with a pumping station called the Warragamba Emergency Scheme was installed below the present dam.

In 1943, the Metropolitan Water, Sewerage and Drainage Board had geologist William R. Browne examine the proposed site . Browne found a more suitable location and continued his advisory work until the dam was completed. The lead engineer was Thomas H. Upton . Construction of the dam began in 1948 and lasted until 1960. This is how Lake Burragorang, one of the largest drinking water reservoirs in the world, was created.

The gravity wall was made of 3 million tons. (= 1.2 million m³) concrete poured. In order not to let the temperatures rise too sharply during the hardening process, ice had to be added to the liquid concrete - which was the first time this happened in Australia at the time - and cooling pipes had to be installed that were filled with chilled water.

According to a new estimate of the annual flood risk rainfall in the years 1987–1989, the dam wall was raised by a further 5 m and an additional drain was installed on the east side.

In 2006, as part of the Deep Water Storage Recovery Project, the base of the dam was pierced in order to be able to use the deepest, previously unusable water reserves of the reservoir. Since this part of the water does not flow out by gravity, a new pumping station had to be installed in the buildings of the former Warragamba Emergency Scheme . The usable amount of water could be increased by 8%.

Storage volume

The reservoir today has a usable capacity of 2027 million m³. Before the end of the Deep Water Storage Recovery Project in April 2006, it was only 1,857 million cubic meters.

There are fears that the population development in the greater Sydney area will cause the demand for drinking water to continue to rise well into the 21st century. The city's population is growing by around 50,000 every year and by the end of 2003 the water had to be rationed. Every major drought creates further difficulties.

There have been times when the lake was emptied excessively. Since it was last completely filled in 1998, there has been extremely little rainfall in the catchment area of the Warragamba River. On February 8, 2007, the previous lowest level was reached with only 32.5% of the full capacity; by the end of 2008 it rose again to 60%. To ensure the drinking water supply of Sydney, the government of the state of New South Wales had a reverse osmosis plant built in Kurnell .

After extensive rainfall in spring 2012, the lake reached its full height again after 14 years and the excess had to be drained.

Access to the lake

Lake Burragorang is surrounded by a 3 km wide drinking water protection zone, which must not be entered. There are two access corridors for hikers, from Mount Mouin to Mount Cookem and from Beloon Pass to Yerranderie . There is limited access for road vehicles on firebreak W4 from Sheahys Creek to Yerranderie.

power plant

The power plant at the Warragamba dam is switched on as soon as the water level in the reservoir has risen to 1 m below the maximum capacity. It delivers an electrical output of 50 MW, but since 1998 the water level in the lake has not reached the height required for operation.

Data of the dam

Image of Lake Burragorang from space (November 1985). In the upper left corner (looking towards the southeast) you can see the western suburbs of Sydney. In the middle and slightly below is also a winding corridor from civilization to Katoomba and Blackheath in the forested mountains.

Height: 142 m
Crown length: 351 m
Crown width: 8.5 m
Base width: 104 m
Width of the middle drain: 94.5 m
Width of the auxiliary outlet (at the mouth): 190 m
Length of the auxiliary outlet: 700 m
Electrical output of the power plant: 50 MW

Data of the reservoir

Usable volume at maximum water level: 2027 million m³
Total volume at maximum water level: 2031 million m³
Area: 75.3 km²
Length: 52 km
Shore length: 354 km
Greatest depth: 105 m
Catchment area: 9051 km²
Average rainfall: 840 mm / year

Web links

Commons : Lake Burragorang - Collection of Images, Videos, and Audio Files

Individual evidence

^ Steve Parish: Australian Touring Atlas . Steve Parish Publishing Pty. Ltd. Archerfield QLD (2007). ISBN 978174193232-4
^ The Wollondilly Region of NSW - Natuaral Attractions - Burragorang Valley . Stonequarry.com.au
^ WV Aird: The Water Supply, Sewerage and Drainage of Sydney . MWS & DB. Sydney
^ William R. Browne (1884-1975) . Australian Dictionary of Biography
↑ http://www.smh.com.au/environment/weather/warragamba-bursts-flood-warning-issued-20120420-1xc6x.html Sydney Morning Herald April 20, 2012
^ Neil Paton: Sydney and Blue Mountains Bushwalks . Kangaroo Press. Sydney (2004). P. 339

[1] Steve Parish: Australian Touring Atlas . Steve Parish Publishing Pty. Ltd. Archerfield QLD (2007). ISBN 978174193232-4

[2] The Wollondilly Region of NSW - Natuaral Attractions - Burragorang Valley . Stonequarry.com.au

[3] WV Aird: The Water Supply, Sewerage and Drainage of Sydney . MWS & DB. Sydney

[4] William R. Browne (1884-1975) . Australian Dictionary of Biography

[5] ttp://www.smh.com.au/environment/weather/warragamba-bursts-flood-warning-issued-20120420-1xc6x.html Sydney Morning Herald April 20, 2012

[6] Neil Paton: Sydney and Blue Mountains Bushwalks . Kangaroo Press. Sydney (2004). P. 339