Wivenhoe Dam
Encyclopedia
Wivenhoe Dam is a dam
across the Brisbane River
a little way upstream from Locker Creek. The dam creates the artificial Lake Wivenhoe. The dam wall is located about 80 kilometres (49.7 mi) by road from the centre of Brisbane
, Queensland
, Australia
.
Wivenhoe dam was planned in the early 1970s as a flood mitigation and water storage dam. The 1974 Brisbane flood
, highlighted the need for flood protection South East Queensland
. The lake also forms part of the water storages for the Wivenhoe Power Station.
Wivenhoe Dam consists of an earth and rock embankment
2.3 kilometres (1.4 mi) long and 50 metres (164 ft) high. It has a concrete
spillway
section on which five steel crest gates are installed. The gates, at 12 metres (39.4 ft) wide and 16.6 metres (54.5 ft) high, are among the largest of their type in the world. The dam also has an auxiliary spillway to stop over-topping.
The dam's reservoir has a total storage capacity of 2.61 cubic kilometre (0.626172299957188 cu mi), of which 1.16 cubic kilometre (0.278298799980973 cu mi) is used for urban water storage. Its surface area is 109.4 square kilometres (42.2 sq mi) and it has a 462 kilometres (287.1 mi) shoreline. 200 properties were acquired to provide the 337.5 square kilometres (130.3 sq mi) of land required for the dam. The catchment area is approximately 7020 square kilometres (2,710.4 sq mi) and has an average annual rainfall of 940 millimetres (37 in). The dam holds twice as much water as Sydney Harbour
and is about seven times bigger than Hinze Dam
at the Gold Coast
. Wivenhoe Dam contributes to the Gold Coast's water supply.
. Built in the late 1970s - early 1980s as a multifunction facility by a consortium of construction companies including Thiess Brothers, Wivenhoe dam provides a safe water
supply to the people of Brisbane and adjacent regions.
Additionally, Wivenhoe Dam serves as the lower storage in a pumped-storage, hydro-electric
generating facility, the Wivenhoe Power Station. The upper reservoir is formed by Splityard Creek Dam
, of earth and rock construction, with a capacity of 28700 millilitre.
Under normal conditions the dam supplies water via pipeline to both Tarong Power Station and Tarong North Power Station, but during drought conditions only supplies water to Tarong North.
the dam is designed to hold back 1.45 million megalitres (1.18 million acre feet) of additional water for flood mitigation
or 225% capacity. Under the water release plan which is defined by law, excess water must be released from the dam within seven days of it reaching 100% capacity. Between April 2004 and September 2008, a 165 metres (541.3 ft) wide auxiliary spillway with a three-bay fuse plug
was installed on the western portion of the dam to further mitigate flooding. In 2007, a feasibility study concluded that Wivenhoe Dam failed to satisfy the Australian National Committee on Large Dams
(ANCOLD) guidelines on acceptable flood capacity.
>
In June 1983, the partially completed dam mitigated a potentially severe flood that may have caused damage equal to the 1893 Brisbane flood
. Construction work was complete by 1985.
, estimates there was a population of 800 in 2010 but many are swept out of the dam when the spillway is opened and that their food source of molluscs and clams is insufficient to maintain the lungfish in the dam.
Self-sustaining populations of lungfish have lived in dams in South East Queensland for over 100 years since 1896. Lungfish were originally restricted to the Mary and Burnett river systems but due to perceived threats to their survival they were introduced to other rivers and dams, including the Brisbane River, in 1895–1896.
This was done to improve the viability of the species.
>
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...
across the Brisbane River
Brisbane River
The Brisbane River is the longest river in south east Queensland, Australia, and flows through the city of Brisbane, before emptying into Moreton Bay. John Oxley was the first European to explore the river who named it after the Governor of New South Wales, Thomas Brisbane in 1823...
a little way upstream from Locker Creek. The dam creates the artificial Lake Wivenhoe. The dam wall is located about 80 kilometres (49.7 mi) by road from the centre of Brisbane
Brisbane
Brisbane is the capital and most populous city in the Australian state of Queensland and the third most populous city in Australia. Brisbane's metropolitan area has a population of over 2 million, and the South East Queensland urban conurbation, centred around Brisbane, encompasses a population of...
, Queensland
Queensland
Queensland is a state of Australia, occupying the north-eastern section of the mainland continent. It is bordered by the Northern Territory, South Australia and New South Wales to the west, south-west and south respectively. To the east, Queensland is bordered by the Coral Sea and Pacific Ocean...
, 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...
.
Wivenhoe dam was planned in the early 1970s as a flood mitigation and water storage dam. The 1974 Brisbane flood
1974 Brisbane flood
The 1974 Brisbane flood occurred in January 1974 in Brisbane, Queensland, Australia, when waterways in the city experienced significant flooding...
, highlighted the need for flood protection South East Queensland
South East Queensland
South East Queensland is a region of the state of Queensland in Australia, which contains approximately two-thirds of the state population...
. The lake also forms part of the water storages for the Wivenhoe Power Station.
Wivenhoe Dam consists of an earth and rock embankment
Embankment dam
An embankment dam is a massive artificial water barrier. It is typically created by the emplacement and compaction of a complex semi-plastic mound of various compositions of soil, sand, clay and/or rock. It has a semi-permanent waterproof natural covering for its surface, and a dense, waterproof...
2.3 kilometres (1.4 mi) long and 50 metres (164 ft) high. It has a concrete
Concrete
Concrete is a composite construction material, composed of cement and other cementitious materials such as fly ash and slag cement, aggregate , water and chemical admixtures.The word concrete comes from the Latin word...
spillway
Spillway
A spillway is a structure used to provide the controlled release of flows from a dam or levee into a downstream area, typically being the river that was dammed. In the UK they may be known as overflow channels. Spillways release floods so that the water does not overtop and damage or even destroy...
section on which five steel crest gates are installed. The gates, at 12 metres (39.4 ft) wide and 16.6 metres (54.5 ft) high, are among the largest of their type in the world. The dam also has an auxiliary spillway to stop over-topping.
The dam's reservoir has a total storage capacity of 2.61 cubic kilometre (0.626172299957188 cu mi), of which 1.16 cubic kilometre (0.278298799980973 cu mi) is used for urban water storage. Its surface area is 109.4 square kilometres (42.2 sq mi) and it has a 462 kilometres (287.1 mi) shoreline. 200 properties were acquired to provide the 337.5 square kilometres (130.3 sq mi) of land required for the dam. The catchment area is approximately 7020 square kilometres (2,710.4 sq mi) and has an average annual rainfall of 940 millimetres (37 in). The dam holds twice as much water as Sydney Harbour
Port Jackson
Port Jackson, containing Sydney Harbour, is the natural harbour of Sydney, Australia. It is known for its beauty, and in particular, as the location of the Sydney Opera House and Sydney Harbour Bridge...
and is about seven times bigger than Hinze Dam
Hinze Dam
The Hinze Dam, also known as Advancetown Lake, supplies most of the water provided to Gold Coast City in Queensland, Australia. Some water is drawn from Little Nerang Dam and until recently northern suburbs received water from Wivenhoe Dam. It was completed in 1976 and expanded in 1989. Advancetown...
at the Gold Coast
Gold Coast, Queensland
Gold Coast is a coastal city of Australia located in South East Queensland, 94km south of the state capital Brisbane. With a population approximately 540,000 in 2010, it is the second most populous city in the state, the sixth most populous city in the country, and also the most populous...
. Wivenhoe Dam contributes to the Gold Coast's water supply.
Purpose
The dam was designed as a response to the floods that damaged Brisbane in 19741974 Brisbane flood
The 1974 Brisbane flood occurred in January 1974 in Brisbane, Queensland, Australia, when waterways in the city experienced significant flooding...
. Built in the late 1970s - early 1980s as a multifunction facility by a consortium of construction companies including Thiess Brothers, Wivenhoe dam provides a safe water
Drinking water
Drinking water or potable water is water pure enough to be consumed or used with low risk of immediate or long term harm. In most developed countries, the water supplied to households, commerce and industry is all of drinking water standard, even though only a very small proportion is actually...
supply to the people of Brisbane and adjacent regions.
Additionally, Wivenhoe Dam serves as the lower storage in a pumped-storage, hydro-electric
Hydroelectricity
Hydroelectricity is the term referring to electricity generated by hydropower; the production of electrical power through the use of the gravitational force of falling or flowing water. It is the most widely used form of renewable energy...
generating facility, the Wivenhoe Power Station. The upper reservoir is formed by Splityard Creek Dam
Splityard Creek Dam
Splityard Creek Dam, of earth and rock construction, forms the upper reservoir for a power station.Owned and operated by CS Energy, Wivenhoe Power Station is located on the eastern side of Wivenhoe Dam, north west of Brisbane...
, of earth and rock construction, with a capacity of 28700 millilitre.
Under normal conditions the dam supplies water via pipeline to both Tarong Power Station and Tarong North Power Station, but during drought conditions only supplies water to Tarong North.
Flood mitigation
During a floodFlood
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...
the dam is designed to hold back 1.45 million megalitres (1.18 million acre feet) of additional water for flood mitigation
Flood mitigation
Flood mitigation involves managing the effects of flooding, such as redirecting flood run-off, rather than trying to prevent it altogether. It is management of people, through measures such as evacuation and dry/wet proofing properties for example....
or 225% capacity. Under the water release plan which is defined by law, excess water must be released from the dam within seven days of it reaching 100% capacity. Between April 2004 and September 2008, a 165 metres (541.3 ft) wide auxiliary spillway with a three-bay fuse plug
Fuse plug
A fuse plug is a collapsible dam installed on spillways in dams to increase the dam's capacity.The principle behind the fuse plug is that the majority of water that overflows a dam's spillway can be safely dammed except in high flood conditions. The fuse plug may be a sand-filled container, a...
was installed on the western portion of the dam to further mitigate flooding. In 2007, a feasibility study concluded that Wivenhoe Dam failed to satisfy the Australian National Committee on Large Dams
ANCOLD
ANCOLD is the Australian National Committee on Large Dams. It is an association that sets national standards in relation to large dams and their environs...
(ANCOLD) guidelines on acceptable flood capacity.
January 2011
The largest ever recorded inflows for the dam occurred in January 2011. On 11 January 2011, Wivenhoe Dam reached its highest level ever, 191% and rising, as it held back floodwater and reduced impacts downstream. Because it is an embankment dam, it was not designed to spill over its crest or overtop and there is a risk that if waters spilled over the crest, this could erode the dam wall and potentially cause the dam to fail. To prevent this, the dam was designed and built to include a second emergency spillway. During the peak of the flooding event the dam water level reached 60 centimetres (23.6 in) below the auxiliary spillway height.Facilities
Lake Wivenhoe is also a camping and outdoor recreation destination. Camping sites are provided at Captain Logan and Lumley Hill Areas. The managed camping facilities at Captain Logan Camp include hot showers, barbecues and toilets, and are adjacent to playgrounds, kiosk, boat hire and boat ramps at Logan Inlet. Cormorant Bay, Hamon Cove and Spillway Common also have facilities for picnic.Recreational activities
A Stocked Impoundment Permit is required to fish in the dam. Swimming is permitted and camp sites have been established. Electric and non-powered boating with a permit is allowed, but domestic animals are banned.Construction
Wivenhoe was initially investigated for a dam site in the 1890s and again in 1933. Further investigations into a dam began in the mid 1960s. In November 1971, Government approval was given to proceed with construction. Acquisition of lands of the submerged portion of the dam began in March 1973. In 1976, the Government gave approval to proceed with construction of the pumped storage hydro-electric scheme. Total cost for the hydro-electric project was A$450 million. In March 1977, the first construction contract was awarded. The dam was designed by the Queensland Water Resources Commission.In June 1983, the partially completed dam mitigated a potentially severe flood that may have caused damage equal to the 1893 Brisbane flood
1893 Brisbane flood
The 1893 Brisbane flood, occasionally referred to as the Great Flood of 1893 or the Black February flood, occurred when the Brisbane River burst its banks on three occasions in February 1893. It is the occurrence of three major floods in the same month that saw the period named "Black February"....
. Construction work was complete by 1985.
Recycled water
In 2006, emergency plans for placing fully treated recycled water from the Western Corridor Recycled Water Scheme into the dam to supplement supply were made public. Sixty million litres of recycled water was to be pumped into the dam by early 2009. Increasing rainfall from 2008 and a public outcry over water quality issues resulted in the plan for recycled water to enter the region's drinking water supply to be cancelled.Fauna
The dam is home to the vulnerable Australian lungfish. Anne Kemp, a researcher from the University of QueenslandUniversity of Queensland
The University of Queensland, also known as UQ, is a public university located in state of Queensland, Australia. Founded in 1909, it is the oldest and largest university in Queensland and the fifth oldest in the nation...
, estimates there was a population of 800 in 2010 but many are swept out of the dam when the spillway is opened and that their food source of molluscs and clams is insufficient to maintain the lungfish in the dam.
Self-sustaining populations of lungfish have lived in dams in South East Queensland for over 100 years since 1896. Lungfish were originally restricted to the Mary and Burnett river systems but due to perceived threats to their survival they were introduced to other rivers and dams, including the Brisbane River, in 1895–1896.
This was done to improve the viability of the species.
Statistics
- Stream Bed Level at Structure (AHD): 23 m (75.5 ft)
- Embankment or Crest Level (AHD): 79 m (259.2 ft)
- Type of Structure: Embankment (4000000 m³ (5,231,802.5 cu yd)) and Concrete (140000 m³ (183,113.1 cu yd))
- Regulator Valves: 2 x 1.5 m (4.9 ft) diameter
- Average Evaporation (per year): 1872 mm (73.7 in)
See also
- Bridges over the Brisbane River
- List of reservoirs and dams in Australia