Climate-resilient water supply for a mine in the Chilean Andes

Climate change is affecting flow volumes and regimes in glacier- and snow-melt-fed catchments. Together with increasing demands for water, this is putting many water users under increasing water security risk. The mines of the high Andes are one user group experiencing increased water stress. This paper illustrates the climate change problem using a 40 year hydro-climate data set from the headwaters of the Aconcagua basin in central Chile and describes the integration of climate, hydrology, mine water system and financial risk models to evaluate potential water supply solutions. It is concluded that existing water supplies are not sufficiently secure under baseline conditions and less secure under future climate scenarios. Recirculating water from the tailings storage facility, despite the large capital and operations costs involved, is considered the optimal climate-resilient solution and also offers social and environmental advantages. However, considerable modelling uncertainties exist, primarily related to spatial precipitation.