Moreno, J, Martin, J & Luppnow, D 2012, 'Thickened tailings water balance – dealing with excess water', in R Jewell, AB Fourie & A Paterson (eds), Paste 2012: Proceedings of the 15th International Seminar on Paste and Thickened Tailings, Australian Centre for Geomechanics, Perth, pp. 65-71, https://doi.org/10.36487/ACG_rep/1263_06_Moreno (https://papers.acg.uwa.edu.au/p/1263_06_Moreno/) Abstract: Thickened tailings facilities are often designed to contain limited amounts of supernatant water, or even planned to rely on evaporative capacity of the receiving environment. While this is feasible depending on particular site conditions, it may be difficult to estimate water storage volumes. The latter is necessary to size a cost-effective pond for managing free water released from the tailings mass and it is one of the components when deciding whether to evaporate it or to return it into the process. This paper presents some of the design issues found by the authors when dealing with excess water for thickened tailings facilities. The approach is to discuss water balance timescales, incorporating true-surface flux boundary infiltration models, variability of the underflow density and probabilistic inputs. The objective is to identify the most influencing factors when designing water management elements for thickened tailings facilities.