The process of finding optimal solution for utilization of hydro-energetic potential of a river flow is a very complex procedure, because it is necessary to find a compromise between an energetically optimal solution and a solution with lower negative influence on the environment and sociological conditions, which is often contradicatory in practice. In order to show more precisely the complexity in choosing an optimal solution for utilization of hydro-energetic potential of a river flow, a mathematical model of multi-criteria optimization and multi-criteria rating for different variants of utilization of the River Moraca basin is presented in this paper.