Coordinated deliveries of environmental water flows are supporting river health across the northern Murray–Darling Basin, as summer conditions place increasing pressure on water quality and connectivity.
The Commonwealth Environmental Water Holder is delivering water in the Border Rivers and Gwydir catchments to support local environmental outcomes and maintain a connection with the Barwon-Darling River.
The Barwon-Darling summer refresh flows began in late December 2025 and are planned to continue through early February, in response to drying conditions that emerged late last year.
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Why summer environmental flows are critical
Summer is a high-risk period for many inland river systems, particularly during extended hot and dry conditions.
In the Barwon River near Mungindi, flows had ceased for almost a week over late December and early January, while rising temperatures contributed to declining water quality.
Environmental water deliveries during this period help maintain minimum flows, support deeper refuge pools for native fish and reduce the risk of water quality deterioration.
How the current water deliveries are being managed
Approximately 4,960 megalitres of Commonwealth Environmental Water is being released from Glenlyon Dam in the Border Rivers catchment.
In the Gwydir valley, two additional releases from Copeton Dam are flowing along the Gil Gil Creek and the Mehi River, supporting native fish movement and improving connectivity with the Barwon River.
Around 17,980 megalitres will be delivered from the Gwydir catchment, with the three coordinated releases expected to continue for about a month across the Border Rivers, Gwydir and Barwon-Darling systems.
Benefits for river connectivity and water quality
The summer refresh flows are delivering multiple environmental benefits, including reconnecting rivers and creeks that had become fragmented under low-flow conditions.
Deeper pools are being maintained in the Dumaresq, Macintyre, Gwydir and Barwon-Darling rivers, providing critical refuge for native fish during hot weather.
The flows are also helping to improve water quality and wet riverbanks and creek edges, supporting healthier riparian vegetation.
Recent localised rainfall in the upper Barwon catchment near Collarenebri has further bolstered the environmental flows as they move downstream.
Coordinating water delivery across jurisdictions
Environmental water is actively managed and protected as it flows through the Barwon-Darling system.
CEWH staff are working closely with Queensland and New South Wales government agencies, including environmental water managers and fisheries specialists, to plan, coordinate and deliver the releases.
While parts of the northern Basin received above-average rainfall during 2025, drying conditions began in November and have continued into 2026.
CEWH said conditions will continue to be monitored through the summer, with further environmental water deliveries planned before autumn if required.