Basin Plan

The Murray-Darling Basin Plan was developed as a requirement of the Commonwealth Water Act 2007. The Basin Plan determines the amount of water that can be extracted annually from the Murray-Darling Basin for consumptive uses, including urban, industrial, and agricultural uses. This volume is called the Sustainable Diversion Limit, and represents a volume that can be used while ensuring the environmental outcomes and functions of the rivers, waterways, groundwater, and wetlands of the Basin.

The Murray-Darling Basin Authority (MDBA) determined that the average baseline diversion level for surface water in the Basin in 2009, prior to the implementation of the Basin Plan, was 13,623 GL. Based on scientific research, ecological modelling, and social and economic studies, the MDBA has determined that the long term Sustainable Diversion Limit (SDL) for surface water is approximately 10,873 GL per year, or 2,750 GL lower than the 2009 baseline. This difference was recommended to be bridged by a combination of SDL adjustment projects and water recovery, including licence buybacks and infrastructure projects. More information about Sustainable Diversion Limit Adjustments.

Under the Basin Plan, there is an SDL for the Basin as a whole, with additional SDLs applicable to individual valleys and catchments. To meet the SDLs, water will be managed through Water Resource Plans (WRPs), which will replace the existing NSW Water Sharing Plans under which water is currently managed. WRPs will set out the rules and arrangements under which water is managed, including annual limits on water take, the delivery of environmental water, management during extreme events, and strategies to achieve water quality standards. WRPs are currently under development with input from Stakeholder Advisory Panels.

Supply and efficiency measures

The Basin Plan states that up to 650 GL of the water to be recovered can be offset through Supply measures, or works to achieve equivalent environmental outcomes with less water. The Basin Plan also provides for the recovery of up to an additional 450 GL for the environment through efficiency measures funded by the Commonwealth, provided they have a neutral or positive socio-economic impact. More information about Supply and Efficiency measures.

Constraints management

Under the Basin Plan, the MDBA has also developed a strategy to manage constraints, where a constraint is any rule or structure which limits the volume and timing of environmental water delivery within the Basin. Constraints include physical structures, river management practices, and river height operational limits.
While easing constraints will not independently lead to the recovery of more water, work completed by the MDBA has shown that it will allow better outcomes to be achieved through the use of environmental water. More information about constraints measures and specific projects.

Complementary measures

In 2016, the water ministers agreed to consider implementing a range of complementary projects intended to contribute to the triple bottom line outcomes under the Basin Plan.  
Complementary measures are projects that do not provide water offsets or an offset volume, but which help to provide improved environmental outcomes through a range of other interventions. These include management activities such as:

  • The installation of fishways and fish diversion screens
  • Carp management activities including release of the carp herpes virus
  • Investments and infrastructure to manage cold water pollution, and
  • Habitat restoration and riparian management activities.

These projects are intended to be part of an integrated approach to addressing environmental issues, and seek to provide a ‘more than water’ approach to environmental management. Complementary measures projects remain at the conceptual stage, and funding for them has not yet been made available.

In 2017, the MDBA commissioned the CSIRO to assess the relative benefits of complementary measures. Their findings are available on the MDBA website.

Relevant policies and reports

A range of policies and measures are required to be in place to underpin the SDL projects and ensure they can provide maximum benefits to the environment. These policies are aimed at maximising the benefits of the delivery of environmental water, as well as helping to track and account for water recovery towards the SDL.
Also included in this section are reviews and reports on the implementation and effects of the Basin Plan.