In 2012, Sustainable Diversion Limits (SDLs) were introduced as part of the Murray-Darling Basin Plan and came into effect on 1 July 2019.
Prior to the establishment of the Murray-Darling Basin Plan, growth in the amount of water taken from the Murray-Darling Basin to support agriculture, industries, cities and towns had led to the emergence of environmental impacts, water quality issues and water shortages. The Murray-Darling Basin Plan, of which the SDLs are a key feature, was established to manage water resources and protect the Basin for future generations.
SDLs ensure that water is available for the environment, whilst retaining flexibility for consumptive use within the limits.
Brickworks Billabong, image credit: Mallee CMA
They do this by limiting the volume of water that can be extracted from each of the Murray-Darling Basin’s 29 surface water areas and 80 groundwater areas.
Specifically, they limit the long-term average annual volume that can be extracted from both surface water and groundwater in Victoria’s catchments.
Victoria is required to report annually on compliance against the SDLs. These reports are published by the Murray-Darling Basin Authority (MDBA) following each water year (July to June).
Water Resource Plans
Under the Basin Plan, Victoria was required to develop Water Resource Plans for each of its three surface water and two groundwater water resource plan areas. Victoria has two water resource plans that cover these areas, which have been accredited by the MDBA and show how the state will comply with sustainable diversion limits. See more .
Sustainable Diversion Limit Compliance
SDL compliance is calculated following the close of each water year (July to June). The Department of Environment, Land, Water and Planning (DELWP) works with water sector agencies to collect water data. This data retrospectively informs the annual actual take and annual permitted take for the preceding year.
Actual take is the volume of water actually taken from waterways in a given water year. It is determined through metering, or otherwise estimated where metered data does not exist.
Permitted take is the annual limit corresponding to a catchment’s SDL. This is the volume allowed to be taken from a river system for consumptive purposes in a given water year. It is calculated retrospectively.
Computer-simulated models representing Northern Victorian water resource systems are updated with climate and streamflow data. These models are used to determine the annual permitted take under the climatic conditions experienced in that year.
The volume actually taken in the year is compared against the volume of annual permitted take to determine whether each system is compliant with its SDL.
More information:
Page last updated: 27/09/22