The simultaneous efficient use of water and energy in long distance hydraulic transport of copper or iron concentrates in dynamic energy and/or water cost scenarios has been recently studied as an optimization problem (Ihle, Int. J. Miner. Process, 2012, submitted), including static input parameters of hydraulic interest, such as the specific gravity of solids, slurry particle size distribution and loose packing concentration. It is common that such variables fluctuate throughout the concentrate line operation, and thus the optimal estimated values in the light of the aforementioned optimization model. In the present paper, a continuation of the latter analysis including the effect of input parameter variability by means of a Monte Carlo analysis is proposed. Results show that, under a variety of unit water and energy cost scenarios, lack of process follow-up in front of relatively small variations of input parameters might cause important effects in optimal water and energy consumption, ultimately resulting in increased operational costs. By taking a copper concentrate long distance pipeline example case detailed in Ihle (2013b), present simulations reveal fluctuations on water and energy use close to 8% and 17%, respectively, whereas total costs may have variations up to 18%. (C) 2013 Elsevier B.V. All rights reserved.