In current study, an irrigation examination and acquisition of environmental water in Kor River fields, that is dominated from Doroudzan dam to Bakhtegan Lake, was done by an integrated economy-environmental model. The model was considered by economic, hydrologic and agronomic components. In the economic component, an optimal harvesting of water was done using non-linear programming in two scenarios; with and without environmental water constraint. Solutions from simulation of environmental data in the hydrologic component, was used as initial data in the economic component. In the agronomic component, actual crop yield in wet, normal and dry years was determined using the relationship between crop yield and irrigation water amount. Results showed that, the current allocation pattern of surface water in wet, normal and dry years in Kor River basin is different from the optimal pattern. Water pricing without considering demand and supply and the absence of water markets in the region can be the causes of this difference. Additionally, optimal cropping pattern of the region was determined by the model that can be taken into account for preservation of surface water resources.