Commonwealth environmental water is water which is made available for the purposes of protecting or restoring the environmental assets of the Murray-Darling Basin.
Why do we need environmental water?
About 40 per cent of the Murray-Darling Basin's natural river flow is diverted for human use, including for irrigation, in an average non-drought year.
Over time reduced flows have caused environmental problems, including:
- increased salinity
- increased algal blooms
- diminished native fish and bird populations
- poor wetland health
How will environmental water help the Murray-Darling Basin?
Commonwealth environmental water that is held in the Murray-Darling Basin is required to be managed in accordance with the environmental watering plan that forms part of the Murray-Darling Basin Plan.
Commonwealth environmental water supports Basin communities and industries by ensuring sustainable water use with benefits such as:
- improving the ability of wetlands to naturally filter water to improve its quality for drinking and irrigation purposes
- improving fishing, swimming and boating opportunities, generating tourism
- increasing native fish and bird populations that will better control invasive insects
- increasing the number of native birds and bees to pollinate agricultural plants
How is environmental water managed?
Commonwealth environmental water is actively managed to ensure that the maximum outcome is achieved from the available water. At any point in time, the options for managing water include delivering it to environmental assets within the current year, carrying over water to future years by leaving it in storage (where possible), or trade of water.
The use of Commonwealth environmental water is supported by a network of environmental water partners throughout the Basin, such as environmental water advisory groups, catchment management authorities, state governments, river operators, scientific organisations and site managers. These partners are helping to manage Commonwealth environmental water by proposing options for where it is best used, helping to deliver the water, and to monitor the outcomes.
Environmental watering actions are undertaken by:
- adding water to complement existing river flows
- using infrastructure to release water from dams, through river operating structures, such as weirs and regulators, and through irrigation channel networks
- working with river operators to mimic natural flows. For example, pulse flows encourage fish movement and spawning, and base flows support refuge habitats.
The objectives for the use of Commonwealth environmental water vary depending on conditions as set out in the table below. This approach ensures that the most effective objectives are pursued depending on conditions and water availability.
|Extreme Dry||Dry||Moderate||Wet||Very Wet|
|Ecological watering objectives||Avoid damage to key environmental assets||Ensure ecological capacity for recovery||Maintain ecological health and resilience||Improve the health and resilience of aquatic ecosystems||Build future capacity to support ecological health and resilience|
Key areas of the Basin are still recovering from extended drought. Commonwealth environmental water will continue to support this ecological recovery to strengthen the resilience of Basin rivers and wetlands to future droughts.
How is environmental watering monitored?
Monitoring and evaluation will help determine the extent to which environmental water is meeting its aims and where there is scope for improvement. It also will provide information to support good governance, adaptive management, and build knowledge.
Annual and Outcomes reports are published to provide further information on the use of Commonwealth environmental water. In addition specific monitoring arrangements are put in place for significant uses of water.
Examples include monitoring of the outcomes from use of environmental water delivered in June 2011 to the Murrumbidgee River by Charles Sturt University; monitoring the response of fish to the delivery of environmental water in the Edward-Wakool river system by the NSW Narrandera Fisheries Centre and Murray Catchment Management Authority; monitoring the ecological response of Commonwealth environmental water delivered during 2011-12 to key areas of the Murray Darling Basin (Edward-Wakool river system, Lower Murrumbidgee River, Murray River, Goulburn River and Broken Creek) by the Murray-Darling Freshwater Research Centre in collaboration with the University of NSW, the University of Melbourne and Charles Sturt University; and monitoring the response of environmental water delivered to the Lower Murray River (including the Lowers, Coorong and Murray Mouth) by the South Australian Research and Development Institute.
Photo point monitoring and webcams are providing up-to-date and easily accessible information on watering actions at some sites. To watch the webcam videos, see Webcam.