Wyangala Dam is a large water storage facility located in the southwest slopes area of New South Wales

New South Wales

New South Wales is a state of :Australia, located in the east of the country. It is bordered by Queensland, Victoria and South Australia to the north, south and west respectively. To the east, the state is bordered by the Tasman Sea, which forms part of the Pacific Ocean. New South Wales...

, Australia

Australia

Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...

. The dam

Dam

A dam is a barrier that impounds water or underground streams. Dams generally serve the primary purpose of retaining water, while other structures such as floodgates or levees are used to manage or prevent water flow into specific land regions. Hydropower and pumped-storage hydroelectricity are...

 is situated below the junction of the Lachlan River

Lachlan River

- Course :The river rises in the central highland of New South Wales, part of the Great Dividing Range, 13 km east of Gunning. Its major headwaters, the Carcoar River, the Belubula River and the Abercrombie River converge near the town of Cowra. Minor tributaries include the Morongla Creek...

 and Abercrombie River

Abercrombie River

The Abercrombie River is a river in New South Wales, Australia, flowing from Mount Werong westward to the Wyangala Dam near Cowra. The river is a tributary of the Lachlan, which it joins at Wyangala lake....

. It was the second water storage project to be constructed by the Water Conservation and Irrigation Commission of N.S.W. The dam is used for irrigation

Irrigation

Irrigation may be defined as the science of artificial application of water to the land or soil. It is used to assist in the growing of agricultural crops, maintenance of landscapes, and revegetation of disturbed soils in dry areas and during periods of inadequate rainfall...

 purposes, flood

Flood

A flood is an overflow of an expanse of water that submerges land. The EU Floods directive defines a flood as a temporary covering by water of land not normally covered by water...

 mitigation and town water supply. It is the only dam on the Lachlan River system, which feeds the Murrumbidgee River

Murrumbidgee River

The Murrumbidgee River is a major river in the state of New South Wales, Australia, and the Australian Capital Territory . A major tributary of the Murray River, the Murrumbidgee flows in a west-northwesterly direction from the foot of Peppercorn Hill in the Fiery Range of the Snowy Mountains,...

, which in turn feeds the Murray River

Murray River

The Murray River is Australia's longest river. At in length, the Murray rises in the Australian Alps, draining the western side of Australia's highest mountains and, for most of its length, meanders across Australia's inland plains, forming the border between New South Wales and Victoria as it...

.

Geography

The small settlement of Wyangala is located downriver of and adjacent to the dam. The name came about as a station called Wyangala was located in the area. The original village is under the water level and can only be seen when the dam is close to being dry. The next largest nearby town is Darbys Falls. The nearest large town is Cowra

Cowra, New South Wales

Cowra is a town in the Central West region of New South Wales, Australia in the Cowra Shire. It is located on the Mid-Western Highway, 317 kilometres west of Sydney on the banks of the Lachlan River at an altitude of 310 metres above sea level. At the 2006 census Cowra had a population of 8,430...

, approximately 20 kilometres northwest of the dam.

Wyangala Dam has a catchment area of 8,300 km² and maximum storage capacity of 1,220,000 ML.

History

The original dam wall was constructed between 1929 and 1935, and was one of the last dams in New South Wales which utilised a railway or tramway system for construction purposes. The current earth and rock wall was constructed between 1961 and 1971 due to fears that the original dam wall was beginning to lift away from its base and as a result, it was feared that it would not be able to withstand a major flood. The original dam wall can be seen when the water level is around 30%
An update of the present dam wall has commenced in 2010. The work means the road across the dam wall will have to permanently close.

The dam was close to the epicentre of an October 2006 earthquake measuring 4.6 on the Richter Scale. The minor tremor triggered a standard inspection of the dam structure which found there was no impact on the dam from the earthquake.

Water entitlements were down to just 10% of normal availability in 2008. Some inflows to the dam later in the year allowed restrictions for high security licence holders to be relaxed. In late 2009, drought

Drought in Australia

Drought in Australia is defined as rainfall over a three month period being in the lowest decile of what has been recorded for that region in the past. This definition takes into account that drought is a relative term and rainfall deficiencies need to be compared to typical rainfall patterns...

had reduced the water storage level to 4.5%.