The Murray–Darling Basin (MDB) is one of Australia’s most ecologically and economically significant regions. Stretching across 4 states and one territory, it encompasses approximately one million square kilometres – about one-seventh of the Australian continent – and supports extraordinary biodiversity, including dozens of water-dependent threatened species and ecological communities. It also underpins Australia’s most productive agricultural region and is of deep cultural significance to First Nations peoples.
Yet the MDB is also one of the world’s most degraded and biologically invaded river systems. Decades of water extraction, habitat modification, cold water pollution and the unimpeded spread of invasive species have left the Basin’s ecosystems in a profoundly diminished state. The listing in 2026 of the River Murray downstream of the Darling River and associated aquatic and floodplain systems as a critically endangered threatened ecological community (TEC) is a stark signal of how severe conditions have become [1].
The Murray-Darling Basin Plan (the MDB plan) is built principally around recovering environmental water – restoring some of the flows taken from rivers over many decades. Environmental water is essential, and progress under the MDB plan has been meaningful. However, water alone cannot restore the MDB’s ecological integrity. As the discussion paper for this review acknowledges – and as is confirmed by the conservation advice for the listed TEC [1], the Native Fish Recovery Strategy [2], and the 2025 MDB assessment of resilience, adaptation and drivers of change [3] – restoring environmental flows must be integrated with addressing the non-flow drivers of ecological degradation.