Utilization of mine water resources and managing water in open pit mines is increasingly important in water-stressed areas. This paper aims to review information and present new data and discussion on water that is utilized during mining of black coal and brown coal in Eastern Australia. Coal from underground and open pit mines is produced for export and generation of electricity in the Australian National Electricity Market (NEM). Utilization of mine water resources in this context refers to water that is extracted or seeps into a mine void, water that is used by mine operations, or water that is available from the mine to be utilized for other uses (e.g. for irrigation), either during mine operation or after closure during mine site rehabilitation. Trends of water utilization over recent years with primary energy generation will be presented, along with associated water utilization for coal at NEM scale, and for selected mine sites. Challenges for management of water resources in a catchment (watershed) context are considered, particularly open pit mines that are located on floodplains, with increased large rainfall events, and reduced water availability over the long-term due to climate change. Rehabilitation options for open pits after mine closure typically favor pit lakes for various beneficial uses, however, deficits of available water mean that it may take decades to hundreds of years for hydraulic equilibrium. Examples are presented of small to large pit scales (35-2000 hectare pit areas, with <20, 20-1000 and >1000 Gigalitre volumes). The goals of safe, stable and sustainable management of open pits requires reliable models of potential hazards of pit interactions with aquifers, wetlands and rivers.    
 

open pit mine,water,rehabilitation,watershed