Great Artesian Basin, c.670,000 sq mi (1,735,300 sq km), between the Eastern Highlands and the Western Plateau, E central Australia, extending S from the Gulf of Carpentaria, Queensland, to NE South Australia and N New South Wales. It is the world's largest artesian water-bearing area. The arid basin receives water from the Eastern Highlands as rain is absorbed by porous rock and flows underground toward the center of the saucer-shaped basin. Thousands of wells, some over 1 mi (1.6 km) deep, tap underground water-bearing rock formations. The rolling surface of the basin supports a pastoral economy mainly based on livestock watering systems. The highly mineralized artesian water cannot be used for agriculture.