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AUSTRALIA'S LARGEST RIVER SYSTEM

WHAT IS THE MURRAY-DARLING BASIN?

The Murray–Darling Basin is Australia’s largest river system, and one of the biggest systems in the world. It covers over a million square kilometres of land in south-eastern Australia, collecting the water draining west of the Great Dividing Range.

Much like an enormous bowl, the Basin collects water that flows inland to the west across flat floodplains, forming rivers, creeks and wetlands as it goes. Passing through five states and territories — Queensland, New South Wales, Australian Capital Territory, Victoria and South Australia — its water eventually flows out to sea at Goolwa in South Australia.

Although the two longest rivers in the Basin are the Darling and Murray rivers, the system includes 23 major rivers in all.

Throughout the Basin there is great variation in climatic conditions and landscapes. From the warm, sub-tropical environment in the north, the Basin ranges through cooler, humid highlands to the east; cold alpine country further south; temperate regions in the south-east, and hot, arid plains in the west before reaching the sea.

Australia-Basin

QUICK FACTS

Australia’s largest river system
Total area over one million km2
Longest rivers — Darling and Murray
Total of 23 major rivers
Outlets into the sea at Goolwa, SA
Passes through five states and territories
Produces over one-third of Australia’s food

BASIN ENVIRONMENTS

Across the Basin’s vast area, water flows in river channels; creates lakes and wetlands (such as billabongs, marshes, mudflats, mangroves); spreads across floodplains; recharges groundwater (often called the water table) and eventually creates an estuary environment where the fresh water of the river meets the salty sea water.

This variety of environments within the Basin supports a huge range of Australia’s plant and animal life. Many plant and animal species rely on the seasonal changes of water flow for their survival. Wetlands are an extremely important environment for many fish and bird species that need them for their feeding and breeding cycles.

The diversity of environments also allows the production of a great range of food types across the Basin, including tropical fruits in the north, dryland cropping and livestock grazing to the west, and cooler weather produce found in the southern regions.

RIVERS OF THE MURRAY–DARLING BASIN

Rivers graph

BASIN BIODIVERSITY

The Murray–Darling Basin is home to hundreds of species of native fauna and flora. The river and surrounding environments support many fish, birds, marsupials, reptiles, amphibians and insects, and terrestrial (land) and aquatic (water) plants.

Both plants and animals rely on the seasonal flooding and drying cycles of the river system for their survival. For example, trees such as mighty river red gums need to ‘get their feet wet’ at different times but also need to dry out for new seedling trees to grow.

This variety of plants and animals is called biodiversity and is the foundation of a healthy ecosystem. We all depend on healthy functioning ecosystems because they support our daily needs and many of our most important industries, such as agriculture, forestry, fisheries and tourism.

Squirrel Glider

LIFE IN THE BASIN

The Basin’s waterways sustain the land and communities surrounding them. It is home to over two million people and is Australia’s most important agricultural region. Producing over one third of Australia’s food supply, the Basin is often described as ‘Australia’s food basket’.

Its large area and climatic range means Basin land is used for a variety of agriculture. The majority is used for grazing, however, more than 100 different types of crops and livestock are grown in the Basin, including cereal grains, fruits, vegetables, grape vines, nuts; rice, cotton; sheep, dairy and beef.

Wheat Harvesting