Excessive extraction of water from the Great Artesian Basin for pastoral use over the past century combined with large scale mining ventures in recent times, such as Olympic Dam and Santos, has led to significant impacts on the ecological sustainability of the springs. Arrows represent water flow paths. The majority of the water enters the GAB on the western slopes of the Great Dividing Range in Queensland, where the permeable sandstones appear at the surface. Smaller quantities of water are also thought to enter from the Western Desert in the south-east region of the Northern Territory. Research has shown that the water can take up to 1.5 to 2 million years to travel from the recharge areas in eastern Queensland to the discharge areas around Lake Eyre in SA, which means that the water in this region is fossil water.
Arrows represent water flow paths.
Due to the size and complexity of the GAB, it supports many spring complexes where the groundwater is forced to the surface. The south-western region of the GAB around Lake Eyre contains the largest number of active and unique springs. Some springs have characteristic mounds which have been formed by the combined action of water, sand, silt and clay and the deposition of limestone from the groundwater. Arrows represent water flow paths. Due to their isolation in the desert over many millennia, they have developed unique ecology with many rare and endangered species of flora and fauna.