In a context of water scarcity, managers are dealing with quantitative and qualitative management of surface and groundwater resources. For a long time, scientists and water managers have looked at groundwater and surface water as two separate entities. Through the Charente basin example, we explain how a coupled surface-groundwater modelling can improve water management for low flows. The papers is structured into three parts: (1) a global presentation of water resources and water management situation of the Charente basin; (2) the place of modelling techniques and tools in quantitative water management; and (3) according to the Charente basin's water management situation and goals, discussion around the choice of an adapted model for low flow water management, comparison with the decision support system model use currently in Charente (TBR) and first conclusions concerning coupled model usefulness in water management