This work aims at studying the results of an optimization mode/applied to the Paranaiba river basin, Brazil This system is made by the junction of three river branches located In a region with a well-defined seasonal hydrological behavior The ratio between the total energy storage in the system and the active storage for every reservoir is evaluated from the optimal operational results. This relationship allows recognizing systematic patterns on the relative use for every reservoir, when compared to the entire system. The main parameters that define reservoir behavior are identified, with highlights on the position of the power station In the cascade, the relationship between the river flow and the active storage, and the installed capacity of the power station In addition, the parameter "hydrological scenario" is also another factor that defines the relative use of the reservoirs.1731726