Water for the River Murray channel

The Government of South Australia works with the other Basin states (Victoria and New South Wales), the Murray-Darling Basin Authority and the Commonwealth Environmental Water Holder (CEHW) to deliver water for the environment to the entire river channel.

The specific ecological objectives for environmental watering in the river channel are to:

• enable carbon, nutrients and seeds to move from the floodplain to the channel
• provide areas of slow flow and areas of faster flows
• maintain water quality for phytoplankton, plants and animals
• flush salt from the river into the Southern Ocean
• disperse organic and inorganic matter and animals between river and wetlands
• control erosion and sedimentation build-up within normal ranges
• establish groundwater and soil conditions to maintain native vegetation along the river and across the floodplains
• maintain the river red gums, black box, river cooba and lignum populations in the floodplains
• support a diversity of native flood-dependent and water-dependent plants in the wetlands
• support native fish including Murray cod, catfish, golden perch, silver perch and smaller native fish like Australian smelt, bony herring, Murray rainbowfish, unspecked hardyhead, carp gudgeon, and flathead gudgeon
• prevent populations of non-native fish, like carp, from growing
• provide habitat for frogs, waterbirds, and other fauna.

Find more information about these objectives and specific targets in the Long-term Environmental Watering Plan for the South Australian River Murray Water Resource Plan Area (find it here).

How water delivery works

Water for the environment is released from several upstream sources (such as dams like Hume and Eildon), and travels hundreds of river kilometres over many weeks.

Delivering water to the Channel not only benefits the ecosystems of the Channel, wetlands, floodplains and weir pools along, it also travels to the end of the system and helps keep the Murray Mouth open, allowing salt, nutrients and sediment to move through.

The effects of Channel (and floodplain) watering vary depending on the flow conditions we are able to deliver but can include:

• creating faster flows in the river channel to support native fish and the transport of seeds, propagules and nutrients
• adding water to flow peaks to raise water levels and inundate wetlands and floodplain, therefore supporting native plant growth (including long-lived trees such as river red gum, black box and river coobah).

Timing

Watering requirements are identified annually, guided by long-term ecological monitoring data and requirements from the SA River Murray Annual Environmental Watering Plan and the Long-Term Environmental Watering Plan for the SA River Murray Water Resource Plan Area. The volume and timing of water for the environment delivered to the Channel each year vary, although the majority is typically prioritised to arrive in spring or early summer.

Does watering work?

Long-term scientific monitoring tracks the ecological condition of the channel in connection with the goals listed above. Monitoring also informs decision-making around how we manage delivery of water for the environment. The monitoring program includes trees and understorey vegetation, fish, frogs, waterbirds, woodland birds, soils and groundwater.

The CEWH Flow-MER (Monitoring Evaluation and Reporting) in the Lower Murray collects data on ecological outcomes in the channel. The monitoring program collects data on vegetation, fish, microinvertebrates and water quality. Annual reports from the monitoring program are available here.

Highlights from 2023-2024 ecological monitoring

How to stay informed

• Sign-up to receive the weekly River Murray Flow Report via email for information on when water levels will rise, expected water level depths and the expected duration. View previous reports
• Visit the National Parks and Wildlife Service SA website
• Find out how to get involved in environmental water planning by contacting us at dew.ewater@sa.gov.au
• Subscribe to our mailing list to receive updates on your chosen location and hear about opportunities to get involved.

More information

• Southern Connected Basin Environmental Water Committee annual reports
• Basin-Wide Environmental Watering Strategy
• Environmental watering plans
• Environmental watering results and outcomes.