Abstarct: Today, excessive use of water is one of the biggest problems affecting human society. As in most parts of the country, precipitation is often negligible and sometimes appears as destructive floods, we can use the construction of water reservoirs as a management method for optimal use. In this research, the hierarchical analysis process using the geometric mean technique in the GIS environment has been used to locate suitable areas for the construction of coastal reservoirs. Accordingly, nine effective criteria consistent with the local conditions of the region, including topography, geology, hydrology, fault, economic and social conditions, environmental, security, permeability, and climate have been considered. In this regard, the information laxyers related to each of the selected criteria were classified and prioritized in the GIS environment and were weighted baxsed on two methods of hierarchical analysis (AHP) and network analysis (ANP). In this way, questionnaires including pairwise comparison of criteria were prepared and made available to expert experts. Oral judgments were used to complete the questionnaire and Expert Choice and Super Decisions software were used to perform calculations. According to the results obtained from the weighting of factors, the fault (0.455) and topography (0.044) respectively allocated the highest and lowest weight among the criteria. Finally, by combining and overlapping laxyers, a zoning map of suitable areas for the construction of reservoirs was obtained. Zoning maps were classified into four classes. According to the obtained results, a large percentage of the area of the western cities of Mazandaran province, including Tenkabon, Ramsar, Babolsar and Mahmudabad, are in higher priority for the construction of reservoirs, and it also indicates the accuracy of the results of the AHP and ANP methods, which include almost similar results.