M.A. (Geography and Environmental Management) / Water can be regarded as a scarce commodity in South Africa and one cannot rely solely on the discovery of new water resources to meet the ever increasing demands. Water is arguably the most precious resource in South Africa and its proper management in all spheres of activity is imperative ( Middleton and Stern,1987 ). This is no different in the mining industry where a primary consumptive use of water is in the tailings dams and associated return water. Restricted implementation of Government water plans and a series of droughts has forced users of water to optimise their use of water. A key to correct water management of a tailings disposal system on a gold mine lies in accurate and meaningful water balance. To provide an accurate water balance, quantifying the water loss is necessary. The water loss in a tailings system is mainly due to evaporation and interstitial flow. For the purpose of this study, evaporation is dealt with in more detail.