The Murray–Darling Basin is a one million square kilometre area in the south east of Australia. It is called a Basin because water is collected by the natural landscape before it eventually flows into the two major Basin rivers, the Murray and the Darling.
The Basin is Australia’s most important water catchment, providing water to 2.3 million people, countless native habitats and thousands of farms. It is an area of significant cultural importance to First Nations people and it spans an area that includes parts of New South Wales, Queensland, South Australia, Victoria and the Australian Capital Territory.
You should know
Location and size of the Basin
The Murray–Darling Basin is in the south east of Australia and covers 14% of Australia’s land area. As the map below shows, it covers large areas of New South Wales and Victoria, all of the Australian Capital Territory, and some of Queensland and South Australia.
The Basin is divided into two parts. Water in the northern Basin runs into the Darling River and water in the southern Basin runs into the River Murray.
To the south and east of the Basin are the mountains of the Great Dividing Range. Most of the rivers that flow into the Basin start as fast-flowing streams in these mountains. However most of the Basin lies on flat plains which are not far above sea level, and the rivers in these areas tend to flow more slowly.
Rivers in the Basin
The rivers in the Basin form Australia’s largest river system.
The two main rivers in the Basin, the Murray and the Darling, are two of Australia’s longest rivers.
There are around 20 other major rivers in the Basin, including the Murrumbidgee, Goulburn, Lachlan, Macquarie, and Ovens rivers. The rivers do not flow directly from their sources to the sea, but wind through the land. This means that most of the rivers run slowly, and water soaks into the land along the river. A large amount of water evaporates as the rivers flow, especially in the drier regions.
Most rivers in the Basin flow into the Murray or Darling rivers before the Murray eventually reaches the Southern Ocean. However some rivers, like the Paroo, Lachlan and Wimmera rivers, do not flow into other rivers, but end in wetlands or marshes.
Where the Murray–Darling Basin starts and ends
The Basin gets its water from the many tributaries that flow into the Murray and Darling rivers.
Most of the rivers in the Basin start in the Great Dividing Range. This is a series of mountains on Australia’s east coast, which stretches from the north of Queensland, through New South Wales and into Victoria.
The Basin ends in South Australia where the Murray Mouth meets the Southern Ocean.
The Basin at a glance
- The Murray–Darling Basin covers an area of more than one million square kilometres. It is about the size of France and Spain joined together, or a little bigger than Egypt.
- The Basin covers 14% of mainland Australia, 75% of New South Wales, more than 50% of Victoria, 15% of Queensland, 8% of South Australia and all of the Australian Capital Territory.
- The length of the Basin is almost 1400km, from the source of the Warrego River in Queensland to the headwaters of the Goulburn River in Victoria.
- The width of the Basin is as much as 1200km along the Murray valley in the southern Basin. However most of the Basin measures 800km to 900km wide from the Great Dividing Range in the east to the plains beyond the Darling River in western Queensland and New South Wales.
- The Basin is made up of 22 major catchments (also known as sub-basins).
- The Basin is the 20th largest river catchment in the world.
For a more detailed description of the geography of each river catchment, see the Basin catchment profiles.
