About Kati Thanda–Lake Eyre Basin

Lake Eyre Basin sign, Birdsville track. Photo M Turner

Kati Thanda–Lake Eyre Basin is one of the world's largest internally draining river systems – its streams do not reach the sea.

It spans 1.2 million km², which is almost one-sixth of Australia. The Basin includes large parts of South Australia, the Northern Territory and Queensland, and western New South Wales. The Basin contains nationally important cultural, social, natural and economic values.

Catchment area

At the heart of the Basin lies Kati Thanda–Lake Eyre. At 9,700 square kilometres in area, it is the fourth largest terminal lake in the world. Australia's lowest point, 15 metres below sea level, is found on the bed of the Lake. But Kati Thanda–Lake Eyre usually contains little or no water, as its catchment is entirely within the arid zone.

Land use

Land uses include:

• grazing
• mining
• oil and gas production
• tourism
• conservation and
• Aboriginal activities.

The area is rich in Aboriginal and non-Aboriginal history.

People

About 60,000 people live scattered across the Lake Eyre Basin. They live in towns, such as Longreach and Alice Springs, small settlements like Marree, or isolated homesteads on huge grazing properties. There are also mining developments, notably the Moomba Gas Fields, and Aboriginal communities and outstations, such as Alpurrurulam and Nepabunna.

Many people make their homes in the Basin – graziers, mine workers, Aboriginal people, tourist operators, public servants and conservationists. They bring a range of skills, opinions and beliefs to their communities.

The Basin is part of the arid rangelands where most land is leased for grazing.  Much of the Basin is owned by Aboriginal people or is under Native Title claim.

Aboriginal culture

For tens of thousands of years, the Basin has supported Aboriginal people, reflected today in diversity of Aboriginal cultures and the many sites of cultural significance. Early Aboriginal life in in their traditional country of the Lake Eyre Basin was governed by the boom-and-bust cycles of the climate. Heavy rainfall and flooding of the river channels boosted food production. During dry periods, they sought refuge at scattered waterholes and springs.

Plants and animals

The vegetation of the Basin is made up mostly of desert-adapted plants – mulga, saltbush, spinifex and Mitchell grass. Yet what draws people especially are the big river channels that flow through the arid landscape, and the permanent waterholes, ephemeral lakes and mound springs. Along the creeks the vegetation includes shady and welcoming river gums and coolibahs.

The natural moister areas are important to conserve. They include the Coongie Lakes, which are recognised internationally under the Convention on Wetlands (known as the Ramsar Convention). After rain large flocks of waterbirds gather in the Basin to breed, attracted by the masses of aquatic invertebrate animals and abundant fish in the flooded waterways and lakes.

Threats

Natural extremes of drought and flood make the Basin vulnerable to wind and water erosion, which can be increased by poor land management.

Localised threats include:

• mining infrastructure and works
• vegetation clearing
• damage at waterholes.

Widespread threats include:

• over-grazing
• erosion
• roads and tracks that impede water flow
• pests and weeds.

Water

Creeks and rivers run only for short periods following rain. Rainfall in Australian deserts is sporadic, and river flows in the Lake Eyre Basin fluctuate more dramatically than in any other basin around the world.

When the streams flow, they travel southward towards Kati Thanda–Lake Eyre. The water travels through a huge dispersal system of braided channels, floodplains, claypans, waterholes and wetlands. The shallow water is exposed to extreme evaporation, potentially 2.5 metres per year. Most of the rain falling in the catchment never arrives at Kati Thanda–Lake Eyre.

The Basin is flat, with higher areas in the north-west (the MacDonnell Ranges) and south (the Flinders Ranges). In the flat landscape, water spreads far and wide during flooding. Because of high evaporation over thousands of years, salt has become concentrated in low-lying areas.

Mound springs are natural water seepage from the Great Artesian Basin, whose waters lie buried deep beneath the surface. The springs support rare and confined species. These unusual water bodies add further appeal and conservation value to the unusual aquatic systems of the Lake Eyre Basin.

Working together

The Lake Eyre Basin is still in good health. So that future generations will be able to use and enjoy this special place, lessons can be applied from the Murray–Darling Basin – where over-allocations of water led to a decline in the health of the Basin and a need to re-balance water use to ensure a sustainable working river. Most importantly, no water is diverted from the rivers of the Lake Eyre Basin. With community and industry, governments are supporting a collaborative effort to ensure ongoing health of the river systems. The Lake Eyre Basin Intergovernmental Agreement allows voices from all interests in the Basin to gain a hearing.

The Lake Eyre Basin Intergovernmental Agreement sets out how we work together to maintain the health of the Basin.

If you need more information, contact lebsecretariat@awe.gov.au