Water quality simulation of a future pit lake ... The concurrence of all these phenomena makes the water quality modelling a difficult task in which hydrodynamic, thermal and geochemical considerations have to be studied in a coupled way. For this reason Mike 3 Flow Model FM software package from DHI Water and Environment (Denmark) was selected. Mike 3 comprises three modules, two of which were used in this work: the hydrodynamic module (HD), based on the solution of the three-dimensional shallow water equations considering the temperature evolution, and the Ecolab module, that allows the implementation of any environmental problem in which the evolution of the state variables can be described by means of a system of ordinary differential equations (ODEs, from now on).