Darling Water Savings Project

Australia

The Darling Water Savings Project is a joint feasibility study to investigate options to improve the water supply and management of the Darling River system and Menindee Lakes by developing a 20-year strategic plan for the river system.

The Australian Government’s Water Smart Australia programme will provide 50% of the cost of the study while the remaining 50% will be provided by the New South Wales State Government Department of Natural Resources.

The Menindee Lakes are a series of large (453 sq km) storages which were, in their natural state, ephemeral lakes that were filled only during floods. Between 1949 and 1968 the lakes were turned into permanent storages and have a total capacity when full of 2030 gigalitres (GL), or four times the volume of Sydney Harbour. The lakes are large, shallow storages in an arid area, and therefore the evaporative losses are typically close to one half of the volume stored. This can be as high as 750 gigalitres a year with average losses recently estimated to be 425 gigalitres each year. This is about Melbourne’s annual water use. At present only two of the four main lakes, Pamamaroo and Wetherell, have water in them and the total storage of the system is around 15% of its capacity.

The lakes system is the main water supply for Broken Hill.

In August 2006 an Environmental Impact Statement appraised a series of proposed works for the Menindee system which were designed to improve operational efficiency and in particular to allow the two lower lakes (Menindee and Cawndilla) to be emptied more quickly and in priority to the two upper, and somewhat deeper, lakes. However the reduction in evaporative losses in the works proposed were very small, with median water savings estimated at less than 5 GL per annum. A key focus of the new study must be to identify measures which will substantially increase the reduction in evaporative losses.

Maunsell, in association with Webb, McKeown & Associates and Hassall & Associates Australia, has been selected to undertake the study, which is expected to be completed by February 2007.

Irrigators and local communities are suffering from a prolonged drought and have had restrictions imposed upon them to safeguard Broken Hill’s water supply. Not only will the options identified from the feasibility study have the potential to increase security of supply to users of the Darling River but also the potential to generate savings for the Murray River.

The options identified in the study will have the potential to:

• Improve the environment of the Menindee Lakes;

• Increase security of water supply to Broken Hill and surrounding areas including local Indigenous communities;

• Increase the security of water supply for irrigators dependent on the Darling River; and

• Generate water savings for the Living Murray, which will benefit all the Murray Darling states of New South Wales, South Australia and Victoria.

Community and Stakeholder Participation and Timeframe

Darling River system communities and stakeholders are encouraged to take the opportunity to participate in the feasibility study stakeholder consultation process.

Key aspects of the water savings project timetable include: 

• During October and November 2006 the project team will be engaging with key people and organisations and inviting input and comments from the community, to gain a sound understanding of all aspects of the project,
  
• The feed back will then be incorporated in the development of water saving options, 
  
• Options will then be assessed against a range of criteria, and
  
• Study findings will be reported to State and Federal Government in early 2007.

For more information, go to the Darling Water Savings Project website.