There are three aspects to water management at BHP Billiton Cannington:
The Cannington mining operation uses large quantities of water in mining (dust suppression and drilling), processing (in the grinding mill and flotation and leaching plants), in rehabilitation (eg to water seedlings used for rehabilitating disturbed land) and for domestic purposes in the administration building and village (potable water).
Because of the arid nature of the region there are no permanent bodies of water of sufficient size to supply the mine and processing plant with its water requirements. Therefore, all of the water is obtained from the Great Artesian Basin.
Artesian water is found in layers of porous rocks that may be up to hundreds of metres below the surface. These layers of water-bearing rock extend from the western slopes of the Great Dividing Range across nearly all of outback Queensland to the north east of South Australia. They cover a total area of 1.7 million square kilometres (22% of Australia) and contain 8.7 billion megalitres of water (a megalitre [ML] is a million litres; an Olympic swimming pool contains about 2 ML). This is equivalent to 4.35 billion Olympic swimming pools!
The blue area on this map shows the extent of the Great Artesian Basin.
Because of the higher elevation of the water bearing rocks in the Great Dividing Range the underground water in the basin builds up considerable pressure. This allows artesian water to flow freely from bores and springs over much of the basin, where it is used for drinking water for stock, irrigation of pastures and crops, domestic water in towns, in mining operations and many other purposes.
Water used at BHP Billiton Cannington comes from an aquifer (water-bearing rock layer) 300 metres below the surface in a bore field about 20 km away from the mine. From the borefield the water is pumped along an underground pipe line to the mine site.
The borefield that supplies water to BHP Billiton Cannington.
