Shifting water availability and demand – the implications of climate change

Climate change is projected to decrease river flows by 20% in the Murray–Darling Basin; however, there is a wide range of uncertainty in how this will unfold, which in turn introduces uncertainty in water allocations and trade patterns. The project aims to assess potential changes in water supply and demand across the southern Murray–Darling Basin, supporting government agencies and water users in making informed decisions.

About this project

This project will explore plausible changes to water supply across the southern basin, including spatial and temporal considerations that affect water allocations and drive patterns of water trade. The project will present this information in a way that informs decision making by both government agencies and consumptive users, using a ‘stress testing’ approach.

By stress testing water allocations in the southern connected system, the project will explore how different water entitlements may be affected by climate change. It will investigate the relationship between allocation reliability and various climate impacts, such as altered rainfall patterns and policy influences. This analysis is crucial as climate change could exacerbate existing disparities in water availability and impact agricultural and environmental water demands.

The project builds on methodologies developed for the Goulburn system to apply stochastic modelling across larger, varied regions of the Murray–Darling Basin. This involves generating diverse climate scenarios to simulate potential impacts on water resources. By incorporating feedback from workshops with the stakeholders such as the MDBA, irrigation authorities, and farmers, the project aims to refine these scenarios and identify relevant metrics for decision-making.

Ultimately, this initiative will provide stakeholders with insights into the vulnerability of water allocation systems under climate change. It will guide adaptation strategies for managing water supply reliability in a changing climate, influencing policy and investment decisions across the basin. This includes assessing long-term entitlement reliability and informing future projects within the One Basin CRC aimed at enhancing water management resilience.

Outcomes

The project aims to provide information about the reliability of different water entitlement products, possible future patterns of water trade, and entitlement robustness under variability and change. 

All of this will have significant implications for robust policy and operational decisions, along with individual farm decisions influenced by water availability and price.