Abstract Water scarcity in arid and semi‐arid regions represents a significant obstruction to social and economic development. Also, flood hazards affect the life of many people in these areas. This study aims to develop a new model for integrated management of surface water and groundwater, which involves rainwater harvesting and recharge to groundwater aquifers. Integrated hydrological models, including geographic information system (GIS), watershed modelling system (WMS) and groundwater modelling system (GMS) were used. This research provides an integrated vision for exploiting the rainwater in Wadi Watier, South Sinai, Egypt and shows new insights on how to protect these areas from flood risks and store water to solve the water scarcity in this region. Based on physical properties of sub‐basins and soil properties, fourteen dams were suggested and designed to protect the study area from flood risks; five dams were used for storage and nine dams for groundwater recharge. The results showed that the dams could collect about 160.72 million m3 of rainwater which can be stored or recharged into groundwater aquifers. This will increase the national income and provide stability for residents in these areas that suffer from water shortage. Decision‐makers can use these models for sustainable flood management in similar areas.