Recent droughts in the unstable and uncontrolled development, especially sharp drop in aquifer has led to a significant reduction in dams' inflow and many dams in Iran do not have the performance that planned at the time of the study. One of the crucial dams to entry severe hypotension, are Karkheh. Karkheh catchment is one of the most important watershed in Iran that there are many dams under construction and under study in it. Thus, accurate planning given the impression in recent years and the decline in groundwater levels, which is essential to consider these studies.
To determine the face of the Karkheh basin water resources development, this basin simulated in MODSIM under various scenarios and the results of it were analyzed. Natural runoff model, where the entrance is, the needs of all dams except for a limited number comes at a high level. In the absence of actual runoff model is input in any of the dams studied, needs are not met. In this case, in order to reduce the need for agricultural, agro-second removed in all dams and a relative increase in the supply of agricultural need were observed.