Wyaralong Dam
Encyclopedia
The Wyaralong Dam is a water project that was initiated by the Queensland Government in 2006 as a result of a prolonged drought
which saw the catchment areas of South East Queensland
's dams receive record low rain.
Construction of the dam wall was completed prior to the 2010–2011 Queensland floods
, with the new dam being praised with mitigating the effects of floodwater on the downstream city of Logan.
at Glendower, also near Beaudesert
, was the preferred location and the government subsequently bought back all the land required for the Glendower Dam. A new dam was not expected to be required until 2060 or later and Glendower Dam remained the preferred dam site, the land already fully government owned.
In October 2005, with an election pending, the Queensland government announced Wyaralong Dam as the new preferred option, even after recent studies into possible dam locations found a location upstream on the Logan River
to be a more reliable option. After a series of studies, a Senate Inquiry and much contested information, Federal Environment Minister Peter Garrett
granted approval for the dam in November 2008.
The dam is a storage and regulation facility. It does not discharge directly into the piped reticulation network, but rather discharges back into the natural drainage network of creeks and brooks. Water released from the dam flows downstream along Teviot Brook to Cedar Grove Weir, where it is diverted for treatment and use in the piped network.
Work on access roads began in early 2009 and construction of the dam wall began in early 2010.
The dam wall is 500 m in length and 48 m high. It is constructed from a medium cementitious mix roller compacted concrete. The foundation is a sub horizontal dipping blocky sandstone. The dam is built with a 130m wide uncontrolled central primary spillway and an uncontrolled left bank secondary spillway which commences discharging at the 1:100 year flood level. The dam cross section is rather squat in order to provide sufficient resistance against potential sliding along foundation bedding planes.
The outlet is on the right bank and is capable of abstracting water from any level of the reservoir by the use of baulks. The outlet includes an innovative and operationally complex bidirectional fish lift, which uses a single hopper to transport fish in both upstream and downstream directions.
The twelve kilometres of new road between Boonah
and Beaudesert were constructed under a separate contract by Fulton Hogan
.
and flows in a north easterly direction to join with the Logan River north east of Beaudesert. The Teviot Brook and surrounding land is a recognised Aboriginal Pathway with significant cultural heritage values.
the dam filled to 100% capacity, just one month after its completion. The new dam is being praised for reducing the effects of flooding downstream.
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...
which saw the catchment areas of 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...
's dams receive record low rain.
Construction of the dam wall was completed prior to the 2010–2011 Queensland floods
2010–2011 Queensland floods
A series of floods hit Australia, beginning in December 2010, primarily in the state of Queensland including its capital city, Brisbane. The floods forced the evacuation of thousands of people from towns and cities. At least seventy towns and over 200,000 people were affected. Damage initially was...
, with the new dam being praised with mitigating the effects of floodwater on the downstream city of Logan.
Conception
The site was identified in a 1990 study, “Water Supply Sources in South-East Queensland”, as a future source of water supply for the South East Queensland region. In this report it was ranked 13th out of 15 studied possible dam locations in South East Queensland. A location on the Albert RiverAlbert River (Queensland)
The Albert River is a river in South East Queensland, Australia. Its catchment lies within the Gold Coast and Beaudesert shires and covers an area of 782 square kilometres. The river provides drinking water for the town of Beaudesert....
at Glendower, also near Beaudesert
Beaudesert, Queensland
Beaudesert is a town located on the Mount Lindesay Highway, some 64 km south of Brisbane. It is possibly named after Beau Desert Park, the property of Charles Henry Alexander Paget, 6th Marquess of Anglesey in Staffordshire, England...
, was the preferred location and the government subsequently bought back all the land required for the Glendower Dam. A new dam was not expected to be required until 2060 or later and Glendower Dam remained the preferred dam site, the land already fully government owned.
In October 2005, with an election pending, the Queensland government announced Wyaralong Dam as the new preferred option, even after recent studies into possible dam locations found a location upstream on the Logan River
Logan River
The Logan River is a river in South East Queensland. The catchment is dominated by urban and agricultural land use. Near the river mouth are mangrove forests and a number of aquaculture farms.-History:...
to be a more reliable option. After a series of studies, a Senate Inquiry and much contested information, Federal Environment Minister Peter Garrett
Peter Garrett
Peter Robert Garrett, AM, MP , is an Australian musician, environmentalist, activist and politician.Garrett was lead singer of the Australian rock band Midnight Oil from 1973 until its disbanding in 2002...
granted approval for the dam in November 2008.
The dam is a storage and regulation facility. It does not discharge directly into the piped reticulation network, but rather discharges back into the natural drainage network of creeks and brooks. Water released from the dam flows downstream along Teviot Brook to Cedar Grove Weir, where it is diverted for treatment and use in the piped network.
Construction
The construction was tendered under an alliance contract. In this type of contract risks and rewards are shared by all the proponents including designers constructors and the owner. Queensland Dam Consortium won the tender for the dam's construction, and the Alliance was formed from their members which included Macmahon Construction as the lead contractor, Hydro Tasmania, Snowy Mountains Engineering Corporation, Paul Rizzo and Associates (USA), ASI Contractors (USA) and Queensland Water Infrastructure the special purpose vehicle created by the Queensland Government owner to deliver the project. The Alliance contract for dam construction was for a little over A$100 million. However it was widely reported that the building costs for the dam would total A$333 million. The latter figure includes the cost of the Bromelton Offpeak Storage Project, Cedar Grove Weir and the reconstruction of a length of the Boonah to Beaudesert Road.Work on access roads began in early 2009 and construction of the dam wall began in early 2010.
The dam wall is 500 m in length and 48 m high. It is constructed from a medium cementitious mix roller compacted concrete. The foundation is a sub horizontal dipping blocky sandstone. The dam is built with a 130m wide uncontrolled central primary spillway and an uncontrolled left bank secondary spillway which commences discharging at the 1:100 year flood level. The dam cross section is rather squat in order to provide sufficient resistance against potential sliding along foundation bedding planes.
The outlet is on the right bank and is capable of abstracting water from any level of the reservoir by the use of baulks. The outlet includes an innovative and operationally complex bidirectional fish lift, which uses a single hopper to transport fish in both upstream and downstream directions.
The twelve kilometres of new road between Boonah
Boonah, Queensland
Boonah is a town in south eastern Queensland, Australia. At the 2006 census, the town had a population of 2,285. The area produces vegetables for the nearby Brisbane Markets notably carrots, potatoes, and cereal crops. Beef, pork and timber are also produced locally.The town is positioned near the...
and Beaudesert were constructed under a separate contract by Fulton Hogan
Fulton Hogan
Fulton Hogan is a large infrastructure construction, roadworks and aggregate supplier company in New Zealand, which is also active in wider Australasia....
.
Catchment
Teviot Brook has a 533 km² catchment (to the dam wall) and has its headwaters in the western part of the McPherson RangeMcPherson Range
The McPherson Range is an extensive mountain range, a spur of the Great Dividing Range, heading in an easterly direction from near Wallangarra to the Pacific Ocean coastline. It forms part of the Scenic Rim on the border between the states of New South Wales and Queensland. Further west of the...
and flows in a north easterly direction to join with the Logan River north east of Beaudesert. The Teviot Brook and surrounding land is a recognised Aboriginal Pathway with significant cultural heritage values.
January 2011 Floods
As a result of rainfall during the 2010–2011 Queensland floods2010–2011 Queensland floods
A series of floods hit Australia, beginning in December 2010, primarily in the state of Queensland including its capital city, Brisbane. The floods forced the evacuation of thousands of people from towns and cities. At least seventy towns and over 200,000 people were affected. Damage initially was...
the dam filled to 100% capacity, just one month after its completion. The new dam is being praised for reducing the effects of flooding downstream.