Environmental water

Why do we need to return water to rivers, wetlands and floodplains? Find out more about environmental watering, what it is and why we need to do it, and how governments and communities are working together to help restore the health of the Murray–Darling Basin.

Why do we need environmental water?

In recent decades we have seen the health of the Murray–Darling Basin affected by the combined impacts of droughts and over-use of water resources.

Water resource development has resulted in long-term ecological decline across the Basin from:

  • a reduction in natural small to medium-sized floods
  • reduced flows along the system through to the sea
  • reduced flushing of salt to prevent salinity build up
  • altered seasonality of flow (higher flows which used to happen in winter–spring, now occur in summer–autumn to meet irrigation demands)
  • a reduction in floodplain inundation.

The Basin supports over 30,000 wetlands and rivers and a wide variety of plants and animals. It is a refuge for threatened species and is an important breeding place for birds migrating to Australia from as far away as the Arctic.

A healthy environment, including good water quality, is essential for the people who live and work in the Basin, as well as people outside the Basin who depend on its resources, and value its environment.

The key to improving the health of the Basin's environment is through managing more natural and variable flows.

Following environmental watering, the previously dry river bed is full of water and brimming with life
Before environmental watering, a dry river bed with no water in it. The bush and surrounding land looks dry and dead.
The before and after effect of environmental watering in the Gunbower Forest in early 2010. Photos by David Kleinert.

What are we trying to achieve?

Our environmental objectives are spelt out in the Basin Plan. The Basin-wide environmental watering strategy sets out our long term targets in more detail, including:

  • what environmental outcomes we want from watering
  • how we can work together to achieve these outcomes across borders
  • strategies for managing and using environmental water
  • our approach to determining the Basin annual environmental watering priorities.

Other important elements in the environmental water planning process include the long-term watering plans and water resource plans that the Basin states are preparing for each region.

Each year the priorities are a step towards the long-term environmental outcomes for the Basin, detailed in the Basin-wide environmental watering strategy.

How is environmental water delivered?

Water holders and water managers coordinate the delivery of environmental water with irrigation demands and rainfall. The best outcomes for plants and animals occur when environmental water passes through rivers and wetlands in ways that mimic natural conditions. Flexible and opportunistic management achieves significant environmental results.

Pilby creek following an environmental water release in the Chowilla wetlands. Photo by Corey Brown.

Flooding wetlands and forests does not necessarily mean there will be overbank flows to mimic natural floods. The same effect can be achieved using water management structures. Hattah Lakes, in the Victorian mallee, can receive environmental water by pumping water through a pipeline instead of sending water over the top of the riverbank. This means that the same environmental outcomes can be achieved using less water.

Water managers, including the Australian Government, Basin states, The Living Murray program, and river operators, are working together to achieve more benefits from delivering water. This can result in plants and animals receiving a much needed drink, using water that was already on its way for another purpose.

The MDBA and environmental water managers are constantly improving environmental flow regimes, this includes using the same water for multiple watering events, and returning water to the river so that it can be re-used downstream.    

Where does the water come from?

Water is recovered for the environment through improvements in irrigation infrastructure or water buybacks.  The Australian Government is investing more than $5 billion in water savings infrastructure and on-farm efficiency projects. A capped amount of 1,500 GL of water is being purchased from willing sellers in the market. Together, the water saved and purchased is building the Australian Government's portfolio of environmental water. Some Basin states, The Living Murray program and other smaller programs also have their own holdings.