What is the Great Artesian Basin?

The Great Artesian Basin (GAB) is an underground aquifer system, or artesian basin, located in Australia. Covering almost 1,711,000 square kilometers, it is the largest artesian basin in the country and is the primary source of water for many towns and agricultural regions in the outback.

Here are some key points about the Great Artesian Basin:

1. Size and Location: The GAB spans across the states of Queensland, New South Wales, South Australia, and the Northern Territory. It covers an area of approximately 1,711,000 square kilometers (around 662,000 square miles), making it larger than the state of Texas.

2. Geology: The GAB is a sedimentary basin that formed over millions of years by the accumulation of sediments, such as sandstone, limestone, and shale. These layers of rock create confined aquifers, which allow water to be stored underground.

3. Water Sources: The water in the GAB originates from rainfall in the highlands and coastal regions of Queensland and New South Wales. The water slowly seeps down through the porous sandstone layers and becomes confined between layers of impermeable rock, forming the artesian basin.

4. Groundwater System: The GAB operates as a natural plumbing system, where groundwater flows from recharge areas in the east towards discharge areas in the west and south. The water is stored in porous aquifers and is often pressurized, allowing it to flow to the surface through natural springs or bores (man-made wells).

5. Importance: The GAB is a critical water resource for many rural communities, remote townships, and agricultural activities. It provides water for drinking, irrigation, and livestock farming, sustaining thousands of people and supporting the economy of outback regions.

6. Management: Due to its importance and vulnerability to over-extraction, the GAB is carefully managed by state governments and water authorities to ensure sustainable and equitable water use. Strict controls are in place to limit water extraction, prevent groundwater depletion, and maintain the integrity of the basin.

Overall, the Great Artesian Basin is a valuable natural resource that plays a vital role in sustaining life and economic activities in the arid regions of Australia. Its effective management and conservation are crucial for the future sustainability of this unique and fragile ecosystem.