Australia's largest drainage basin provides one-third of the nation's food supply despite extreme scarcity.

Countries & Cities · Published 15 October 2026 Swipe more like this →

In short: The Murray-Darling Basin is a vast, flat, and arid landscape that sustains a massive agricultural industry. While it covers one-seventh of Australia, its rivers are among the world's least productive in terms of water flow, creating a constant, high-stakes tension between environmental health and the demands of irrigation.

The Murray-Darling Basin spans most of New South Wales and Victoria, along with parts of Queensland, South Australia, and the Australian Capital Territory. It is defined by the Murray and Darling rivers, which drain the interior of south-east Australia. Despite its size, the basin is characterized by low rainfall and high evaporation, resulting in some of the lowest water flow rates of any major river system globally. The hydrology is highly varied; while alpine-fed rivers like the Murray maintain more consistent flows, others in the Darling and Lachlan systems are prone to years of zero flow.

Agriculture is the primary driver of water use in the region, accounting for about 95 percent of the 11,500 gigalitres of water extracted annually for human use. This reliance on irrigation, which supports crops like rice and cotton, has been a source of intense controversy. The system was severely tested during the early 2000s drought, known as the Big Dry, when many rivers ceased flowing entirely. These conditions have led to significant ecological degradation, including the loss of native fish populations and the invasion of non-native species like carp and cane toads.

Management of the basin has evolved from early, limited advisory bodies to the creation of the Murray-Darling Basin Authority in 2008. The authority was tasked with creating a legally enforceable plan to balance environmental sustainability with social and economic needs. The resulting Basin Plan, which became law in 2012, aimed to set sustainable limits on water extraction. However, the process remains fraught with conflict, as rural communities fear for their economic survival while environmentalists argue that the current levels of water diversion continue to compromise the long-term health of the river systems.

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