Murray–Darling basin

The Murray-Darling Basin drains one-seventh of Australia and is by far the most significant agricultural area on that continent. Most of the 1,072,000 square kilometre basin is flat, low-lying and far inland, and receives only modest rainfall. The many rivers it contains tend to be long and slow-flowing, and carry a volume of water that is large only by Australian standards.

The basin drains roughly three-quarters of New South Wales, half of Victoria, a substantial portion of southern Queensland, and part of South Australia. In general, the climate is hot and dry, much of it semi-arid; however the catchment area also includes the inland slopes of the Great Dividing Range, which tend to be cool and have higher rainfall (or, in the case of the Australian Alps which straddle the New South Wales-Victoria border, snowfall).

Although the Murray-Darling Basin receives only 6% of Australia's rainfall, it is the scene of 70% of Australia's irrigation. It contains 42% of the nation's farmland and produces 40% of the nation's food.

Total water flow in the basin averages 14,000 gigalitres per year, of which 11,500 gigalites is removed for irrigation, industrial use, and domestic supply. Agricultural irrigation accounts for about 95% of the water removed.

Major streams

• Murray River
  • Darling River
    • Paroo River
    • Warrego River
    • Condamine River
    • Barwon River
    • Gwyder River
    • Namoi River
    • Macquarie River
  • Murrumbidgee River
    • Lachlan River
    • Molonglo River
  • Edward River (anabranch)
  • Goulburn River
  • Kiewa River
  • Mitta Mitta River