Supply and efficiency measures
Supply and efficiency measures are projects which can adjust the quantity of water required to be recovered to reach the Sustainable Diversion Limit (SDL) for the Murray-Darling Basin. For more information on how the adjustment mechanism works, see Sustainable Diversion Limit Adjustment Mechanism.
Supply measure projects are able to offset a quantity of water which would otherwise be required to be recovered from the Basin, to a maximum volume of 650 GL. They seek to provide equivalent environmental outcomes with a reduced volume of water, and hence reduce the amount of water required to be recovered to meet the SDL. Project examples include environmental works, changes in river operations, and works to reduce evaporation losses. The most recent modelling of the supply measure projects, which has now been incorporated into an amendment of the Basin Plan, indicates an offset of up to 605 GL.
There are currently 36 proposed supply measure projects across the Murray-Darling Basin, of which NSW is the lead or co-proponent state on 22. For a complete list of SDL projects, please see the MDBA register of projects.
NSW supply measure projects:
- Improved flow management works at the Murrumbidgee River – Yanco Creek Offtake
- Computer aided river management (CARM) for the Murrumbidgee
- Nimmie-Caira infrastructure modifications
- Hume dam airspace management and pre releases
- Change to inch rule downstream of Hume Dam
- Modification of Murray Weirs
- Snowy Water Licence Schedule 4 Amendments to River Murray increased flows call out provisions
- Review of Barmah-Millewa environmental water allowance rules
Murray and Murrumbidgee valley national parks works
Efficiency measure projects seek to recover additional water for the environment through improving the efficiency of irrigation, to a maximum volume of 450 GL. This recovery is in addition to the 2,750 GL required to be recovered to reach the SDL. Unlike supply measures, the Basin Plan requires that efficiency measures can only be implemented to the extent that they have socioeconomically neutral or positive outcomes.
Efficiency measure project example include replacing or upgrading less efficient methods of irrigation or water delivery, and lining channels to reduce water within irrigation networks. Efficiency measures work by reducing the amount of water needed for consumptive use, with the savings made available for environmental use.
The Ministerial Council commissioned Ernst and Young (EY) to complete an analysis of the proposed efficiency measures to determine if and how they could be implemented in a socioeconomically neutral manner. The EY report determined that there were a range of efficiency measures which could be implemented in a socioeconomically neutral way, if they were designed and selected based on principles to achieve neutrality. The report is available from the MDBA website.
The NSW Government is supporting the Commonwealth Government to explore where upgrades to or investment in major irrigation infrastructure operators could provide improved efficiencies without reducing the amount of water available for consumptive use.