Methods and system for modeling wellbore treatment operations in which the flow of treatment fluids may be diverted are provided. In one embodiment, the methods comprise: receiving, at a processing component, one or more treatment operation inputs characterizing a treatment operation for a wellbore system comprising a wellbore penetrating at least a portion of a subterranean formation and a treatment fluid comprising a diverter, wherein at least one of the one or more treatment operation inputs comprises the inlet concentration of the diverter in the treatment fluid; and using the processing component to determine a wellbore system pressure distribution and a wellbore system flow distribution based, at least in part, on the one or more treatment operation inputs and a diversion flow model, wherein the diversion flow model captures an effect of the diverter on fluid flow in the wellbore system.