The Water Act 1989 requires a long-term water resource assessment (LTWRA) every 15 years to determine whether water availability has declined or if waterway health has deteriorated for reasons related to changes in flow.

This is Victoria’s first assessment and it covers southern Victoria. An assessment for northern Victoria will start in 2025 to align with the Murray-Darling Basin Plan review scheduled for 2026.

Sharing our water

Water is limited, so under the Act, the Minister for Water manages how surface water (water that flows along our waterways and into and out of dams and reservoirs) and groundwater (water stored underground in aquifers) is shared between users.

Water-sharing arrangements need to be kept up-to-date. The LTWRA is a formal process to consider whether:

  • A long-term reduction in water availability needs to be shared more equitably between consumptive users and the environment.
  • Water-sharing arrangements need to respond to a deterioration in waterway health related to change in flow.

If a LTWRA shows that a review of water-sharing arrangements is needed, this may be done as part of the development of a new Sustainable Water Strategy.

Sustainable Water Strategies (SWSs) identify and manage threats to the future supply and quantity of a region’s water resources, as well as identifying means to improve waterway health. These strategies are used to make decisions about how water is shared between consumptive users (people and industry) and the environment.

Long-term water resource assessment process

The assessment for southern Victoria commenced in August 2018 and was completed in February 2020.

The LTWRA for southern Victoria began with a technical assessment to:

  • Assess water availability in each river basin and aquifer.
  • In cases of long-term declines, identify if the decline has been shared equally between consumptive uses and the environment.
  • Determine if waterway health has deteriorated due to changes in flow.

The technical assessment was undertaken by the Department of Environment, Land, Water and Planning (DELWP) in collaboration with southern Victoria’s water corporations and catchment management authorities.

The draft technical assessment report was made available for public consultation and review by the Environment Protection Authority (EPA) in late 2019. The EPA checked whether the data used were the best available and whether the conclusions reached are supported by the methodology and the data. The EPA endorsed the methodology and conclusions of the LTWRA.

Feedback on the draft assessment from the EPA and the community was incorporated into the final report before being presented to the Minister for Water.

The LTWRA technical assessment has now been finalised.

The final assessment report of the LTWRA was endorsed by the Minister for Water in February 2020. The final LTWRA reports can be downloaded below.

Based on the findings of the LTWRA, in 2020, the Minister determined that a review of water sharing arrangements was required for seven river basins; Barwon, Moorabool, Werribee, Maribyrnong, Yarra, Latrobe and Thomson.

Water sharing arrangements and the opportunities to change how water is shared in the river basins have now been explored through the Central and Gippsland Region Sustainable Water Strategy, as part of broader planning to improve water security now and into the future.

The Strategy sets out actions required to increase the volume of environmental water across the region in response to the findings of the LTWRA. In setting actions, consideration has been given to the range of values that underpin how we share our water: economic, environmental, Traditional Owner cultural values and uses, social and recreational.

The Central and Gippsland Sustainable Water Strategy sets out our commitment to prioritising water savings through water efficiency measures and investing in manufacturing more of our water supplies, including using more desalination and recycled water where it is fit-for-purpose, and better capturing and using the rain that falls on our cities and towns. This will collectively help to free-up river water to get better environmental outcomes and return water to Traditional Owners.

The Strategy identifies options to recover up to 99.5 GL/year over the next decade. It signals that additional water recovery is likely to be required over the longer-term to maintain and improve waterway health under a drying climate.

The Strategy also includes actions to undertake complementary measures, such as building fishways or managing vegetation, in addition to increasing the water available to the environment to enhance the effectiveness of available environmental water and hence maximise the overall benefit to waterway health.

LTWRA interactive map

Explore the interactive map of the Long-Term Water Resource Assessment results for southern Victoria showing current water availability, decline rates and how shared water has changed.

Illustration of Victoria with features overlayed from the interactive map

Page last updated: 08/09/22