Prerequisite policy measures (PPMs) is a term that refers to actions which are put in place to:

  • protect environmental flows throughout the length of the river and between rivers from extraction, re-regulation or substitution
  • allow water for the environment to be released on top of other instream flows, including during unregulated flow events.

When setting the Sustainable Diversion Limit, the Murray-Darling Basin Authority assumes that actions to deliver the above outcomes are in place to allow maximum environmental benefit from use of the Commonwealth’s licensed environmental water. Without these policy measures, more water would be required to meet the environmental outcomes of the Basin Plan, leaving less for consumptive purposes.

Prerequisite policy measures are applied during the operation of the Sustainable Diversion Limit (SDL) Adjustment Mechanism in the Basin Plan. The extent to which these actions were implemented by 30 June 2019 in the River Murray and the Murrumbidgee, will affect the size of any SDL adjustment in 2019 and 2024.

Implementation of PPMs in South Australia focuses on detailing processes and procedures, and making information publicly available to improve transparency.

South Australia provided a range of PPM documentation to the Murray-Darling Basin Authority in June 2019 and the MDBA subsequently assessed these PPMs as being in effect from 1 July 2019. The MDBA also required that PPM policies and associated arrangements undergo a biannual review process.

The current compilation of PPM policies and arrangements, as per the biannual review process (completed 30 June 2023) is provided below. Further refinements of the policy settings will continue as part of the adaptive management approach to improving environmental water arrangements in the Basin.

South Australia’s River Murray Annual Operating Plan for the current water year

South Australia’s River Murray Annual Operating Plan for previous water years

Overview of arrangements and mechanisms used to implement Prerequisite Policy Measures in South Australia

Policy for the Use of River Murray Unregulated Flow (RMUF) in South Australia

Policy for the Application of Losses to Environmental Water

Policy for Environmental Water Return Flow

Policy for Use of Entitlement and Allocation on the Minister’s Reserve Licence

South Australian River Murray Long-Term Environmental Watering Plan

Objectives and Outcomes for Operating the River Murray in South Australia