Present state of the operation procedure manual of HPP Vrhovo, which defines the operation procedures in the range between low and extreme flows, determines appropriate reservoir water levels only in a relation to upstream incoming flows from the gauging stations and consequently doesn’t take the effects of increasing flow levels on the reservoir morphologic conditions into account. A 2D sediment transport model was used to determine new, optimised operating rule curve (ORC) at the HPP Vrhovo dam profile station on Sava River with regard to sediment transport effects on the reservoir bathymetry.