An ancient underground water basin the size of Libya in Australia, known as the Great Artesian Basin, is crucial for the country to avoid a water crisis due to climate change and drought. This vast basin covers 1.7 million sq km and holds 65 million gigalitres of water, making it one of the largest artesian groundwater basins globally. It is slowly replenished by rain filtering through porous sandstone rock, with 1 million megalitres added annually. According to hydrogeologist John Hillier, the basin could potentially meet Australia's water needs for 1,500 years if fully utilized. He and other experts caution that the water supply in the basin is at risk due to declining artesian pressure, which causes water to come to the surface through bores and springs. If the artesian pressure drops too low because of excessive water extraction, the ancient water source may become inaccessible except through expensive pumping. Some parts of the basin are as deep as 3 km from top to bottom, lying up to 2 km below ground. The basin, formed between 100 and 250 million years ago, is made up of alternating layers of water-bearing sandstone aquifers and non-water-bearing siltstones and mudstones. Water from the basin is obtained through bores and is the sole source of water for mining, tourism, and grazing in Queensland, New South Wales, South Australia, and the Northern Territory. The Great Artesian Basin Coordinating Committee states that the underground water from the basin contributes A$3.5 billion (US$2.4 billion) annually to various industries such as farming, mining, and tourism. The mining and petroleum sector uses 31,000 megalitres of water from the basin each year for production processes, including at BHP-Billiton's Olympic Dam mine in South Australia. BHP-Billiton plans to increase its water usage significantly to double production, drawing extra water from the basin and a new desalination plant. Xstrata Plc is also considering the basin as a water source for a large thermal coal mine in Queensland that would produce 20 million tonnes annually for 30 years. The pastoral industry is the largest consumer of water, using 500,000 megalitres annually to irrigate some of Australia's most productive farmlands. Angus Emmott, who owns a cattle property in central Queensland, depends on basin water during droughts. He believes that the bores are essential for the social and economic value of the region. With climate change, the reliance on the Great Artesian Basin will increase, so it is important to use the water efficiently and avoid wastage. Since it was first utilized in 1878, around 87 million megalitres have been extracted from the basin, with up to 90 percent of it being wasted. Due to decreasing water pressure, over 1,000 natural springs have disappeared and one-third of the original artesian bores are no longer flowing. The extraction of ancient basin water into the atmosphere is also contributing to Australia's greenhouse gas emissions, releasing 330,000 tonnes of CO2 annually. A 15-year project called the Great Artesian Basin Sustainability project, which began in 1990, aims to preserve the water supply and the hydraulic pressure needed to access it. Currently, there are about 3,000 bores that release water into 34,000 km of open bore drains, with 90 percent of the water evaporating due to the outback heat. However, more than 1,052 bores have been regulated and many kilometres of open drains have been removed, with pipelines being installed instead, saving 272 gigalitres of water per year. Farmers are now using technology such as mobile phones, satellite, and computer imaging to fence off bores and control livestock access to bores and bore flows. According to Emmott, this change in land management has led to improved pasture and stock management. The capping and piping program has also prevented issues such as bogging of domestic animals, maintenance costs of drains, and soil salination. Farmers and scientists emphasize the importance of sustainable usage of the Great Artesian Basin to prevent a future water crisis due to increased demand on basin water. Emmott emphasized the importance of taking care of communities, as it is crucial for their existence. A $17 million sustainability report on the Great Artesian Basin will focus on ensuring water for future mining, pastoral, and environmental development. The increase in mining activity in the basin due to the global commodities boom has raised concerns about securing groundwater allocations for economic development. Andy Love from Flinders University will lead the study on this issue. Love stated that finding a balance between development and environmental protection is essential, but it cannot be achieved without a better understanding of how much groundwater can be extracted safely.