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Climate variability and change

Changes in global and regional climate patterns are having significant impacts on the availability of water for both communities and the environment throughout the Murray–Darling Basin.

We know changes in global and regional climate patterns will have significant impacts on water availability for both communities and the environment across the Murray–Darling Basin. Many of its effects are uncertain and the timeframes are unclear.

The Murray–Darling Basin Authority (MDBA) works with other Australian Government agencies, including the Australian Bureau of Meteorology, the Commonwealth Scientific and Industrial Research Organisation (CSIRO) and Basin state governments to understand climate risk and manage the Basin’s water resources under these changing conditions.

The Bureau of Meteorology projects rainfall will decrease. Increased variability is also predicted, with declines less certain in the northern Basin, which historically, has a more variable and intermittent rainfall pattern. Overall, the southern Basin is receiving less annual rainfall compared to the long-term average.

In 2012, there was widespread agreement across government that a plan was needed to manage our water carefully and protect the Basin for future generations.

The Basin Plan, which is being implemented, has been developed to ensure climate variability and climate change is considered in real-time, and climate change patterns, measured over decades, are considered through regular reviews. To specifically address climate change, regular 10-yearly reviews of the Basin Plan are required, which allow for emerging climate change patterns to be considered.

Climate variability describes the way climate elements such as temperature and rainfall differ from the average in given months, seasons, years, decades or centuries. Water management practices in the Basin already account for climate variability. Water is allocated to users based on availability. In a wet year, more water will be available compared to a dry year.

 

Key facts

The Murray–Darling Basin is complex, diverse and constantly changing in response to the climate and human activities

The Bureau of Meteorology says average rainfall in the Basin is projected to decrease because of climate change. However, there is much variability predicted, with declines less certain in the northern Basin

Projections suggest a likely increase in drought frequency and severity, while at the same time, heavy rainfall is expected to increase
The CSIRO warns that outflows at the River Murray mouth in South Australia are likely to be influenced by climate change

Less rainfall will affect the storage of water and increase demand from irrigators and communities

Monitoring, new science and evaluation are at the core of adaptive management in the Murray–Darling Basin

 

The Basin Plan has been developed to ensure climate variability and climate change is considered in real-time and climate change patterns, measured over decades, are considered through regular reviews.

Monitoring, new science and evaluation are at the core of adaptive management in the Basin. The MDBA will continue to work in close collaboration with the scientific community and key stakeholders to understand, explore and adapt water management mechanisms to factor in the latest climate change science and build Basin resilience in a drier, hotter future climate.

Expert knowledge

We work with other Australian Government agencies to understand climate risk and manage the Basin’s water resources under these changing conditions. These agencies include the:

  • CSIRO
  • Australian Bureau of Meteorology
  • Department of Agriculture, Water and Environment
  • Basin state and territory governments.

Regular reviews, monitoring and evaluation

There are 2 ‘built-in’ formal evaluations of the Basin Plan. The MDBA conducted a preliminary evaluation in 2017 to monitor progress and shape future management decisions, the 2020 Basin Plan Evaluation was a comprehensive assessment of the plan. A formal 10-yearly review is scheduled take place in 2026, providing an opportunity to adapt the Plan based on lessons learnt and community perspectives.

Monitoring the social and economic conditions of the Basin, and the impact of the Plan on communities, is conducted by the MDBA – with community impacts research conducted as part of the Northern Basin Review, and southern Basin research as part of the MDBA 2017 Basin Plan Evaluation.

The Basin Plan has also been subject to many independent reviews to examine different aspects of water reform and management. For example, an independent assessment of social and economic conditions in the Basin was commissioned by the Commonwealth Water Minister in 2019.

The 2020 Basin Plan Evaluation showed significant progress against key elements of the Basin Plan has been made, but also pointed to areas where more work is required. The MDBA made several recommendations and commitments to improve adaptation to climate change and increasing resilience.

Adaptive management

A cornerstone of the strategy for managing water resources in the Basin is adaptive management – ‘learning as you go’ by trialling techniques, monitoring, and making changes as needed.

Water managers must be flexible and dynamic to ensure the best possible outcomes are achieved. This is the modern way of managing natural resources.

Adaptive management allows governments and communities to adjust their approach in response to current climatic conditions, new information and local knowledge when planning for the future.

The features of this approach are planning, management, monitoring and evaluation. Adaptation can happen at any one of these stages.

The adaptive management approach to environmental watering is a practical example of this method at work. The MDBA and its partners have put in place monitoring programs to assess whether water for the environment is reaching the right places at the right times. Timings, flows and target areas are adjusted in response to the results.
Updated: 29 Apr 2022