A basin of contradictions
The Murray-Darling Basin is a vast, semi-arid region covering over one million square kilometers, or 14% of Australia's landmass. It is the nation's agricultural heartland, producing around $30 billion worth of food and fiber annually and containing 40% of all Australian farms. This enormous productivity depends on a river system that is one of the most variable in the world, prone to extreme droughts and floods. For over a century, management of the basin has focused on regulating the rivers through dams and weirs to provide a reliable water supply for agriculture.
This regulation led to a critical miscalculation: over-allocation. By the late 20th century, state governments had issued water licenses that, in total, promised more water to users than the river system could sustainably provide. The "Millennium Drought" from 1997 to 2010 showed this reality, with river flows reaching historic lows and ecosystems pushed to the brink of collapse. In response, the Murray-Darling Basin Plan was legislated in 2012. This plan aims to manage the basin as a single, connected system and recover 2,750 gigalitres of water per year for the environment by setting Sustainable Diversion Limits (SDLs)—caps on how much water can be taken.