Commonwealth Environmental Water Holder Reaches 20,000-Gigalitre Milestone in Murray–Darling Basin

The Commonwealth Environmental Water Holder (CEWH) announced during National Water Week, held from 19 to 25 October, that it has delivered 20,000 gigalitres of environmental surface water across the Murray–Darling Basin since beginning operations in 2009.

The volume represents approximately 17 years of environmental watering operations aimed at improving the health and resilience of rivers, wetlands, and floodplains in Australia. According to the CEWH, 20,099 gigalitres of surface water has been delivered in total, representing about 93 percent of its available water holdings.

Commonwealth Environmental Water Holder Dr Simon Banks stated that the operations have evolved from individual watering actions at single sites into complex, coordinated events designed to connect multiple river systems and floodplains. Dr Banks noted that the program relies on partnerships with scientists, water managers, landholders, and First Nations groups.

According to data from the agency and its science program, Flow-MER, water deliveries from 2014 through June 2025 supported flows across more than 28,500 kilometres of waterways and inundated over 470,000 hectares of wetlands, lakes, and floodplains through approximately 1,200 watering actions.

The CEWH reported several specific ecological outcomes across the Basin over the 17-year period, including:

• Building resilience across 11 internationally significant Ramsar wetlands.
• Delivering 15,500 gigalitres to support native fish spawning, migration, and survival.
• Allocating 13,000 gigalitres to support river and wetland vegetation.
• Facilitating large-scale waterbird breeding events, including at the Macquarie Marshes and the lower Murrumbidgee floodplain.
• Aiding the recovery of threatened species such as the southern bell frog, Murray hardyhead, and Australasian bittern.
• Flushing 4.3 million tonnes of salt from the Basin to mitigate poor water quality.
• Maintaining river connectivity during dry periods, such as providing 90 percent of flows in the Barwon-Darling in 2017–18, as well as supporting connectivity to the Coorong.

The agency currently manages a water portfolio with an estimated market value of approximately $12 billion, which includes around 2,200 gigalitres in Long-Term Diversion Limit Equivalence (LTDLE) holdings.

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