The Romanian legislation regarding the delimitation of minor riverbeds provides uniform rules for defining the notion of minor riverbed, as well as for regulating the concrete ways of establishing the limits and delimitation in land of the minor riverbeds of surface waters in public ownership of the state. For non-permanent frontal accumulation lakes, the surface of the minor riverbed is assimilated with the surface occupied by water along the entire length of the accumulation basin, at the level corresponding to the transit of the maximum flow with the annual probability of exceedance 50%, representative for characterizing the current flow regime. Within this paper, a case study was carried out for the non-permanent accumulation Ciurea, located on the Nicolina River, in Iași County.