Dam construction and large reservoir projects are essential for sustainable economic developments especially in developing countries like Iran. Such big projects, could have major social and environmental impacts. At this point, Environmental Impact Assessment (EIA) in dam construction is needed in order to study and address the social, environmental as well as economic issues. In the framework of a joint research project between master students of Amirkabir University of Technology in Tehran, Iran, and Ecole Polytechnique Fédérale de Lausanne (EPFL), Switzerland, integrated matrix oriented tools were analysed and improved in order to answer the complex challenge of EIA of a large reservoir and pump-storage hydropower plant. For this purpose, a modified Leopold and ICOLD matrix is used. Furthermore, the Gomez and Probst network thinking method is applied, in order to identify the involved factors and improve the understanding of the complex problem. This methodology is applied to the case of the Azad pump-storage hydropower plant in Iran. This case study highlights better the advantages which is provided in the combined model. The results show that using network thinking analysis approach could enhance the matrix methods and helps in improving the quality of EIA report for large reservoirs and dams.