During the past decades, the command and control approaches were used to access a safe water supply policy. However, traditional methods of water management rarely consider complex interactions and outcomes of water allocations which can show their effects in feedback loops. These methods also might deteriorate the situation in long terms as they have not taken into account the outcome of such plans on the future of a watershed as a whole system. Dynamic simulation methods provide flexible tools to accomplish a holistic analysis. This ability of system dynamics method is used in this research to show the feedback of water allocation. Bookan dam is one of the constructed dams in Urmia Lake basin upstream of which four dams are being constructed. Three well known archetypes are shown in this paper that help to recognize the effect of a reservoir water supply on downstream flow. The result of dam construction and water supply priorities on Bookan dam inflow is investigated too. The difference of inflow reduction to Bookan reservoir for the best and worst policies is about 18.4 MCM which is a significant amount. Also the best preference of water demand allocation for four dams was defined as agricultural demand, domestic demand, industrial demand and environmental demand
