The Wyaralong Dam is a

mass concrete Mass concrete is defined by American Concrete Institute Committee 207 as "any volume of concrete with dimensions large enough to require that measures be taken to cope with the generation of heat from hydration of cement and attendant volume change ...

gravity In physics, gravity () is a fundamental interaction which causes mutual attraction between all things with mass or energy. Gravity is, by far, the weakest of the four fundamental interactions, approximately 1038 times weaker than the stro ...

dam A dam is a barrier that stops or restricts the flow of surface water or underground streams. Reservoirs created by dams not only suppress floods but also provide water for activities such as irrigation, human consumption, industrial use ...

with an un-gated spillway across the

Teviot Brook Teviot Brook is a waterway in South East Queensland, Australia. It rises in the Main Range at Carneys Creek and joins the Logan River The Logan River ( Yugambeh: ''Dugulumba'') is a perennial river located in the Scenic Rim, Logan and Gol ...

that is located in the

South East The points of the compass are a set of horizontal, radially arrayed compass directions (or azimuths) used in navigation and cartography. A compass rose is primarily composed of four cardinal directions—north, east, south, and west—each se ...

region of

Queensland ) , nickname = Sunshine State , image_map = Queensland in Australia.svg , map_caption = Location of Queensland in Australia , subdivision_type = Country , subdivision_name = Australia , established_title = Before federation , establishe ...

, Australia. The main purpose of the dam is for

supply Supply may refer to: *The amount of a resource that is available **Supply (economics), the amount of a product which is available to customers **Materiel, the goods and equipment for a military unit to fulfill its mission *Supply, as in confidenc ...

of potable water for the

Scenic Rim The Scenic Rim is a group of forested mountain ranges of the Great Dividing Range, located south of Brisbane agglomeration, straddling the border between south-eastern Queensland and north-eastern New South Wales, Australia. In 2021, the S ...

region. The dam was initiated by the

Queensland Government The Queensland Government is the democratic administrative authority of the Australian state of Queensland. The Government of Queensland, a parliamentary constitutional monarchy was formed in 1859 as prescribed in its Constitution, as amended f ...

in 2006 as a result of the prolonged

Millennium drought The 2000s drought in Australia, also known as the Millennium drought is said by some to be the worst drought recorded since European settlement. This drought affected most of southern Australia, including its largest cities and largest agricul ...

which saw the catchment areas of South East Queensland's dams receive record low rain. It was completed in 2011.

Location and features

The dam is located approximately north-west of . The dam wall itself is split between the localities of Wyaralong and Allenview, but the bulk of impounded water is within Wyaralong. The Wyaralong Dam was completed prior to the

2010–2011 Queensland floods A series of floods hit Queensland, Australia, beginning in November 2010. The floods forced the evacuation of thousands of people from towns and cities. At least 90 towns and over 200,000 people were affected. Damage initially was estimated a ...

. On January 11, during the flood period, the Mayors of both

Logan City Logan City is a local government area situated within the south of the Brisbane metropolitan area in South East Queensland, Australia. Situated between the City of Brisbane to the north and the City of Gold Coast to the south, the City als ...

and

said they believed that Logan had been spared a great deal of flood damage because of the dam. The concrete dam structure is high and long. The dam wall is constructed from a medium cementitious mix roller compacted concrete, which is a zero-slump concrete that is placed in 300mm thick lifts and compacted with vibratory compactors. The foundation is a sub horizontal dipping blocky sandstone. The dam is built with a 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 dam wall holds back the reservoir when at full capacity. From a

catchment area In human geography, a catchment area is the area from which a location, such as a city, service or institution, attracts a population that uses its services and economic opportunities. Catchment areas may be defined based on from where people are ...

of that includes much of the western portion of the

McPherson 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 N ...

, the dam creates a reservoir with a surface area of . Teviot Brook and the surrounding land is a recognised Aboriginal Pathway with significant cultural heritage values. The dam is managed by

SEQ Water Seqwater is a statutory authority of the Government of Queensland that provides bulk water storage, transport and treatment, water grid management and planning, catchment management and flood mitigation services to the South East Queensland re ...

as part of a

water security Water security is the focused goal of water policy and water management. A society with a high level of water security makes the most of water's benefits for humans and ecosystems and limits the risk of destructive impacts associated with water. T ...

project in the South East Queensland region, known as the

South East Queensland Water Grid The SEQ Water Grid is a region-wide, long term, water supply scheme that provides a sustainable water infrastructure network for the South East region of Queensland, Australia. The project was the largest urban response to the drought in Austra ...

. 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.

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, the site of Wyaralong Dam was ranked 13th out of 15 studied possible dam locations in the region. A location on the Albert River 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. Properties previously acquired by the government are progressively being sold to private buyers. In October 2005, in advance of the state election, 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 The Logan River ( Yugambeh: ''Dugulumba'') is a perennial river located in the Scenic Rim, Logan and Gold Coast local government areas of the South East region of Queensland, Australia. The -long river is one of the dominant waterways in Sout ...

to be a more reliable option. After a series of studies, a Senate Inquiry and much contested information, Federal Environment Minister

Peter Garrett Peter Robert Garrett (born 16 April 1953) is an Australian musician, environmentalist, activist and former politician. In 1973, Garrett became the lead singer of the Australian rock band Midnight Oil. As a performer he is known for his signa ...

granted approval for the Wyaralong 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 The Cedar Grove Weir is a weir located across the Logan River in the South East region of Queensland, Australia. The main purpose of the weir is for potable water storage. Location and features The weir is located northwest of , and southwest ...

, 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 SMEC Holdings Limited (formerly Snowy Mountains Engineering Corporation) is an Australian based-firm that provides consulting services on major infrastructure projects around the world. SMEC undertakes feasibility studies, design, tender and contra ...

, 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 100 million. However it was widely reported that the building costs for the dam would total 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 diversion channel was plugged on 17 December 2010, allowing the dam to begin to fill. The dam site was opened to the public on 3 June 2011. The of new road between Boonah and Beaudesert were constructed under a separate contract by

Fulton Hogan Fulton Hogan is a large infrastructure construction, roadworks and aggregate supplier company in New Zealand, which is also active in wider Australasia. The company was founded by Julius Fulton and Robert Hogan in Dunedin in 1933. In 2013 the c ...

. The dam cost 380 million to construct, including purchasing farmland flooded by the dam reservoir.

Treatment

By late 2012 the dam still had not been connected to the SEQ Water Grid because it contains water so mineralised it is cheaper to produce desalinated water than to treat it. The Wyaralong water treatment plant is expected to cost 235 million to construct. Funding for the plant was planned for the 2014/15 financial year. In 2017 SEQ Water external relations manager Mike Foster stated the Wyaralong Water Treatment Plant wouldn't be necessary until "2030 or beyond".

January 2011 floods

As a result of rainfall during the

the dam filled to 100% capacity, just 25 days after the wall was plugged to hold water, but before its completion. By 10 January during the flood period, the dam held , 80.7 per cent of its capacity. Parts of the dam were still under construction, but its wall was plugged to hold water on 17 December 2010. On 11 January the dam filled and began to overtop at 9:27am, Following the overtopping, in the first 24 hours over of water flowed over the primary spillway and entered the Logan River at Cedar Grove.

References

External links

International Water Power and Dam Construction Magazine
{{WaterQueensland , state=autocollapse Reservoirs in Queensland Logan River Scenic Rim Region Dams completed in 2011 Dams in Queensland Venues of the 2032 Summer Olympics and Paralympics 2011 establishments in Australia