The new approach to water resources management requires, first of all, the combined efforts of professionals from various disciplines such as hydrology, economics, ecology, engineering, and sociology as well as a cross-sectoral integration in the planning and management process. Additionally, the increased water resources problems and the new management approach require improved water resources management tools based on sound scientific principles and efficient technologies. Key characteristics of such improved technologies are that they, to a larger extent than the existing tools, must facilitate an integrated view of water resources as well as cooperation among different disciplines and sectors involved in water resources management. This involves, amongst others, an integrated description of the entire land phase of the hydrological cycle, an integrated description of water quantity, quality and ecology, and integration of hydrological, ecological, economical and administrative information in information systems specifically designed for decision-makers at different levels. To address the multi-disciplinary of water management, we are introduced an integrated approach to water resources management at the basin scale. Integrated water resource management can be described as a facilitated stakeholder process to promote coordinated activities in pursuit of common goals for multiple objective development and management of water founded in sustainable water resource systems. This research develops and applies a comprehensive decision support tool for examining these issues in the river basin scale. Decision making in water resource management is typically a complex and confusing exercise, characterized by trade-offs between socio-political, environmental, and economic impacts. So we are used a decision support system (DSS) for water resources planning and management in systems with multiple disciplines, and multiple decision makers. This DSS is a method based on compound models that is proposed for regional water resources planning involving multiple decision makers. This method combines modeling techniques such as river basin simulation (RIBASIM), hydrological model (SWAT), multicriteria and multiparticipant decision methods, and supports plan generation and evaluation, individual and group preference elicitation, negotiation taking aim at a consensus plan and risk analysis for climate change in future. The integrated use of Scenario Planning and Multi-Criteria Decision Analysis (MCDA) has been advocated as a powerful combination for providing decision support in strategic decisions. So AHP-FUZZY method has been used for water policy or scenario evaluation in our decision processes. In this study, we used the framework to examine a variety of water allocation mechanisms and policy options for the Zayandehrood River Basin in Iran.