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The amount of water available across the Murray–Darling Basin rivers is limited and as result there is high competition from communities, farms, First Nations' cultural needs and the environment. Managing these competing interests doesn’t come without challenges.

Challenges facing the Basin include:

  • social and economic issues
  • evolving water markets
  • ensuring the health of the environment improves
  • climate change
  • drought, floods and bushfires
  • fish deaths
  • salinity
  • algal blooms
  • blackwater events
  • acidic soils.

These issues have led to challenges in maintaining good water quality, improving the health of the environment, plants and animals and sharing water fairly across communities, industries and the environment.

Report water quality issues or fish deaths

Find out who to contact if you need to:

  • report a suspected water quality issue (including blue-green algae or blackwater)
  • get more information about water quality in your area
  • use water after a water quality incident
  • report dead or dying fish in your area.

What you need to know

  • Many of the issues facing the Basin are related. For example, climate change can increase the likelihood of drought in parts of the Basin, which can in turn increase salinity, and increase demand from irrigators.
  • Basin state governments and other bodies to manage these issues and challenges on the ground. The MDBA work in partnership with oversight role Many are addressed by the Murray–Darling Basin Plan. Find out more on how water is managed in the Basin.

Social and economic issues

Across the Basin, people have been dealing with issues such as drought, demographic change, commodity price changes and the biggest water reform in Australia’s history.

The Independent assessment of social and economic conditions in the Basin was commissioned in mid-2019 by the Australian Government. The assessment panel is independent to the MDBA, reporting directly to the Minister responsible for water.

The review highlighted there are underlying issues greater than water reform and a whole-of-government response is needed to address changes in population, industry and technology across the Basin.

Learn more about the Independent assessment of social and economic conditions in the Basin Report and read the MDBA’s response.

Evolving water markets

Water in the Murray–Darling Basin can be bought and sold, either permanently or temporarily. This water is traded on markets – within catchments, between catchments (where possible) or along river systems. This form of trading allows water users to buy and sell water in response to their individual needs. Water trading has become a vital business tool for many irrigators and has evolved over time.

The Australian Competition and Consumer Commission (ACCC) has investigated the suitability of water markets across the Basin. The ACCC was asked to recommend options to enhance markets for tradeable water rights, including options to enhance their operations, transparency, regulation, competitiveness and efficiency.

The ACCC’s final report, released on 26 March 2021, highlights there are significant deficiencies associated with the settings and governance of water trading, which undermines the efficiency of water markets and their dependent industries.

Find out more about the ACCC’s final report and read the MDBA’s submission to the ACCC.

The Australian Government will consider the recommendations from the final report and provide a whole-of-government response.

Making sure there’s enough water for the environment

As agriculture, industries and communities have grown over time, water use has increased dramatically and there is now less water where it once naturally flowed. This has damaged the natural environment in many parts of the Basin. Water for the environment is used to improve the health of rivers, wetlands and floodplains, which helps plants and animals as well as people. Water for the environment provides a healthy environment, which is needed to support agriculture, communities, and First Nations.

Learn more about water for the environment

A challenging variable climate

The Basin has a highly variable climate that is prone to extreme weather events. This has implications for water availability, use and management. Changes in global and local climate patterns are likely to reduce the amount of water available for communities and the environment in many parts of the Murray–Darling Basin. While it is hard to predict the exact effects and when they will happen, it is likely there will be less rainfall, more frequent and severe droughts, as well as more frequent heavy rainfall events.

Learn more about climate change and the Basin

Droughts, floods and bushfires

The Murray–Darling Basin has a highly variable climate. This means it is exposed to both droughts and flooding.

When parts of the Basin are in drought, access to water is limited. This affects the whole river system, including plants and animals, the communities of the Basin, and farming and food production. Even when a drought occurs only in certain areas, the effects can be felt through the entire system.

Learn more about drought in the Basin and flooding in the Basin

After a bushfire, materials such as ash, charcoal, soil, sediment and organic matter can enter waterways. This:

  • reduces the amount of oxygen in the water
  • reduces water quality
  • can lead to blackwater events and fish deaths
  • reduces the amount of water flowing into rivers.

Learn more about how bushfires affect water quality

Visit the Emergency services website for assistance during or after an emergency.

Fish deaths

There have been several mass fish deaths in the Basin in recent years. In many instances the cause of fish deaths are unknown, but it some instances they happen because of low levels of oxygen. Low oxygen levels can be caused by blackwater events, algal blooms or acidic water entering the river system. However, the reason for low oxygen levels can’t always be found, and there may be other causes of fish deaths.

Learn more about fish deaths in the Basin.


Too much salt in the water reduces:

  • water quality
  • the health of plants and animals
  • biodiversity
  • land productivity
  • the amount of water available for human consumption.

If salinity levels were allowed to keep rising, life in the Basin would quickly become impossible for most people, plants and animals.

Learn more about salinity in the Basin.

Algal blooms

A certain amount of algae in the rivers is normal, but too much can cause problems. When blue-green algae multiply rapidly, this is called an algal bloom. Algal blooms can produce toxins that make the water unsafe for people and animals to drink, swim in or use in other ways.

Learn more about algal blooms in the Basin.

Blackwater events

Blackwater events happen when there is too much carbon in the water (from decaying organic matter), making the water appear black. These events:

  • affect water quality in the Murray–Darling Basin
  • harm fish and other aquatic life
  • make it harder to treat water so it is fit for humans to drink.

Learn more about blackwater events in the Basin.

Acid soils

When rivers and wetlands dry out, the underlying acidic soil, known as ‘acid sulfate soil’ can be exposed to oxygen, releasing sulfuric acid into the water. This acid harms the Basin’s plant and animal life and threatens the safety of people and communities.

Learn more about acid soils in the Basin.

How the Basin Plan is improving the health of the rivers

The Basin Plan aims to improve the health of the river. It limits how much water can be used by communities and industries, while leaving enough water in the rivers and on the floodplains for the plants and animals that need it. The Plan is designed to improve the Basin’s long-term health.

The MDBA and Basin state governments work together to improve the health of the Basin and manage the Basin’s water resources. Basin state governments are responsible for implementing policies and projects on the ground. The MDBA is responsible for making sure the Plan is properly carried out so that the rivers of the Basin are managed carefully for future generations.