In arid and semi-arid zones, water resources are faced with several problems, especially the extensive drawdown of the water table and the continuous degradation of quality. Stable isotopes, specifically oxygen-18 (18O) and deuterium (2H), are used in this study to identify the origin of water masses and the history of their movement at the surface and underground. Isotopic tracing also make it possible to understand the groundwater recharge mechanism, to determine the origin of water mineralization and to estimate their recharge attitude. The isotopic values in δ18O and δ2H of Cenomano-Turonian waters are respectively between - 6.3 and 0.5‰ with an average of - 5.2‰ and between - 39.2 and 2.2‰ with an average of - 29 ‰. The majority of points are closed to GMWL and the LMWL. This reflects that the recharge of the Cenomano-Turonian aquifer is ensured by precipitation of Atlantic origin. The 18O vs. EC diagram concentrations show that the groundwater mineralization is governed by dissolution phenomenon. The lack of correlation between 18O and chloride levels indicates that the mineralization is acquired by dissolution of the minerals. This is also confirmed by the hydrogeochemical approach, which suggests that water mineralization is not mainly linked to evaporation or seawater intrusion, but essentially comes from the dissolution of minerals, following water-rock contact. The recharge altitude varies between 400 and 1400 masl. Some points have altitudes far exceeding the maximum altitude of the study area (about 800 masl). This reflects that the recharge zone of these points is outside the study area. The mixing ratios deduced from the mass balance of stable isotopes shows that surface water contributes between 32.16 and 70.42% to the Cenomano-Turonian aquifer recharge. The study provides valuable information on the water isotopes that could be used by policymakers and water managers for more informed decisions about how to allocate and use this precious resource.