Water is seen as key factor for development. Its scarcity raises concerns at all scales. In regards to water resources, Annaba and El-Taref are intimately connected, the different activities (groundwater and superficial), focused on increasing supply, have been considered as a response to water demand.The actual system use of water resources is not able to sustain water needs that are more and more growing in different expansion sectors. Consequently, a strategy should therefore be sought to integrate the various sectoral needs in available water resources in order to reach the economic and ecological sustainability. We will try to respond to this problem by use of Water Evaluation and Planning (WEAP) model. This study is the first attempt to estimate water demand and analysis of multiple and competing uses of hydro-system in Seybouse's Wadi basin and to make comparison with proposed water storage estimates. This model was applied according to five different scenarios which reflect the best and worst conditions of the supply and demand, not only to evaluate water demand deficit, but also to help planners to the alternative management.The model stimulation showed that the area study is sensitive to a serious water scarcity by 2030. It is possible to observe an improvement with integration of other management strategies for a best operating system.