State Water Corporation’s innovative Burrendong temperature control curtain project has won the Australian Institute of Project Management’s Project of the Year award. This accolade, given in recognition of an organisation which has delivered a project with superior performance, rewards outstanding management principles and making important contributions to industry, government and the community. In addition, the Burrendong scheme also won the Engineering for Regional Communities category of the Sydney Engineering Excellence Awards.

CEO of State Water, David Harris, said the awards acknowledged the leading edge projects the corporation was delivering.

"The Burrendong curtain is an example of the innovative infrastructure projects State Water is managing that can restore the riverine environment and bring significant flow-on benefits to surrounding regional communities," he said. "The judges commented on the wide range of design skills, innovative thinking, computer modelling and new fabrication and installation techniques demonstrated in the project which has the potential to be used in other dams across Australia and around the world."

Project manager Guresh Ahuja added: "This is a fantastic achievement and recognises the extensive work that went in to making this Australian-first project a success. This is a great honour for State Water and we hope to see this technology rolled out at other dams in New South Wales following this project."

Prior to the installation, cold water was released from the bottom of the dam resulting in a temperature difference of up to 10 degrees which was harmful to native fish. The project involved construction of a floating curtain, temperature control structure around the intake tower at Burrendong Dam. The flexible structure sits just below the water level to allow warmer surface water to be released downstream through the outlet valve into the Macquarie River, creating a temperature range more habitable for native fish. The curtain can move up and down with the water level via a chain and pulley mechanism to function regardless of the water level of the dam.

Construction of the A$4M curtain was completed on time and on budget in July 2014. It is the first of its type on the world and resulted in A$2-3M of savings compared with the alternative multi-level offtake solution.

The curtain is now fully operational and working as designed. State Water and the NSW Office of Water have funded a research programme to measure its effectiveness and research will continue to monitor water temperature and quality immediately downstream of the dam and throughout the river over the next 12 months. The greatest benefits will be seen when the storage fills. At the moment Burrendong Dam is only sitting at 24% of capacity.

Located near Wellington in NSW, this innovative concept design at Burrendong Dam was funded by NSW Rivers Environmental Restoration Programme. Half of the investigation, design and construction were funded by the NSW Government and half by State Water customers. The construction contractor was Geotechnical Engineering Pty Ltd. Design and construction review was carried out by AMOG Consulting.

Cold water pollution

The project is part of the cold water pollution strategy developed in 2004 by the NSW Government Inter-Agency Group on Cold Water Pollution. Concern had heightened across Southeast Australia about the release of unseasonably cold water from the deeper layers of thermally stratified reservoirs during warmer months. It was seen as a serious threat to the viability and survival of fish and other aquatic fauna in many NSW rivers.

A desktop study by the Department of Infrastructure, Planning and Natural Resources identified nine dams from a shortlist of 93. All nine dams were located on the Murray-Darling river basin and were mostly equipped with fixed intakes that draw water from deeper colder layers of storage during warmer months. The dams considered to be causing relatively large and persuasive water pollution, alongside Burrendong, were Blowering, Hume, Copeton, Burrinjuck, Wyangala, Keepit, Khancoban and Pindari dams. In April 2011 guidelines for managing cold water releases, developed by the Cold Water Pollution Interagency Group were released. A report on Stage 1 of the Cold Water Pollution Strategy was also published in July 2012 and the work is still ongoing.

Burrendong Curtain timescale

  • Concept design completed – June 2011.
  • Contract for the review of environmental factors awarded to Molino Stewart – September 2011.
  • Structural assessment of the intake tower awarded to AMOG consulting – February 2012.
  • Call for expressions of interest for design, fabrication and installation – September 2012.
  • Call for tenders for design, fabrication and installation – February 2013
  • Contract for the design, manufacture and installation of the world’s first cold water mitigation curtain awarded to Geotech – June 2013
  • Design and fabrication completed and installation began – January 2014.
  • Project completion – July 2014.