The depth of an artesian basin varies significantly based on regional geology and the specific subterranean aquifer structure being tapped. For instance, the Great Artesian Basin in Australia—one of the largest and deepest groundwater reservoirs in the world—extends downward from shallow depths in marginal recharge areas to maximum subterranean depths exceeding 3,000 meters (nearly 10,000 feet) beneath the earth's surface in central depression zones. This massive vertical scale traps enormous volumes of water under intense natural hydrostatic pressure between impermeable layers of confining rock and shale, enabling sustained artesian flow across vast arid inland distances.