The methodology developed demonstrates the feasibility and effectiveness of using MOO as a transparent process to explore the trade-offs between different objectives for river system planning. The conceptual model incorporates the major system complexities of conflicting water users, multiple supply storages, and GW/SW interactions. This model is therefore adaptable to an actual representation of the Lachlan catchment, as well as to other areas. These outcomes aid in bridging the gap between use of optimization for water resource decision-making in research and in practice.