The Murray–Darling Basin Plan sets limits on the amount of water that can be taken from the rivers for town, industrial and agricultural use in the Basin. These limits are known as Sustainable Diversion Limits. SDLs are set at Basin-wide, catchment and aquifer scales. The Murray–Darling Basin Authority has estimated the Basin-wide SDL for surface water is 10,945 gigalitres per year (GL/y)1. At the catchment scale, SDLs are implemented through Basin States’ water resource plans.
1 See section 6.04(2) of the Basin Plan 2012
During the development of the Murray–Darling Basin Plan, Basin water ministers requested the inclusion of an adjustment mechanism in the Basin Plan. This would allow for better social, economic and environmental outcomes than would otherwise be achieved by the Basin Plan.
The Basin Plan (at Chapter 7) provides for a mechanism to adjust the SDLs to achieve equivalent social, economic and environmental outcomes with less water recovery. The mechanism enables adjustment of the Basin-wide SDL (up or down) by no more than 5% (about 543GL/y).
Environmental, social and economic outcomes are not to be compromised by this adjustment.
Supply and Constraints Measures
The Australian, New South Wales, Victorian and South Australian governments notified a package of 36 supply measure projects in the southern Basin under the mechanism in 2017.
Supply measures can:
- reduce evaporation at water storages
- manage environmental water more efficiently through using infrastructure or changing river operating rules.
Some constraints measures, activities that address barriers to delivering environmental water, have also been notified as supply measures.
Taking into account these 36 projects, the MDBA determined a supply adjustment to the SDLs of 605GL/y. This means there is more water available for Basin communities.
The Basin Plan Amendment (SDL Adjustment) Instrument 2017 amended the Basin Plan to reflect the change in SDLs (13 January 2018). Combined with changes to the Northern Basin SDLs (the Northern Basin Toolkit), the adjusted SDLs are estimated to be 10,945GL/y. This means we now have an annual Basin-wide surface water recovery target of 2,075GL/y* and 62GL/y of Efficiency measures.
* 2,075GL/y = 2,750GL/y (original water recovery target in the Basin Plan 2012) less the 70GL/y adjustment from the Northern Basin Review and the 605GL/y adjustment from the SDL adjustment in the southern Basin
To allow the 605GL/y increase, at least 62GL/y must be obtained through efficiency measures. This keeps the adjustment within the 5% limit set out in the Basin Plan. Efficiency measures are activities that change water use practices and save water.
Read more about Efficiency measures.
Implementation and delivery
Basin States are responsible for implementing the supply and constraints measures. All projects must be ready to enter into operation by 30 June 2024.
The Australian Government is providing:
- up to $1.3 billion to support the implementation of the package of supply measures
- up to $1.775 billion through the Water for the Environment Special Account for implementing constraints and efficiency measures
- This includes $330 million to accelerate delivery of five SDLAM projects in the Murray and Murrumbidgee, find out more about the acceleration program below:
Check the MDBA website for information on: