The region of Essaouira, situated along the Moroccan Atlantic Ocean, grapples with the inherent instability of water resources, a characteristic often observed in regions marked by arid and semi-arid climates. Understanding these vital resources is of great importance to ensure their management. In the past few decades, the Essaouira region has experienced significant disruptions to its socio-economic and environmental equilibrium due to the dual challenges of climate change and the excessive exploitation of surface and groundwater resources. Climate studies estimate a significant decrease in precipitation and an increase in temperatures over the next 30 years. The study carried out in this work is based on hydrogeochemical data from 2017, 2018, 2019, and 116 samples from 2020. The investigated samples are, respectively, neutral and hypothermal from a pH and T ° point of view. Piezometric monitoring showed a drop in water level throughout the basin. Water mineralization increases from 2017 to 2020. The mineralization is controlled by the effect of marine intrusion and by the dissolution of carbonates and evaporites. This study focuses on assessing the physico-chemical quality of water, specifically the concentrations of major chemical elements (Ca2+, Mg2+, Na+, K+, Cl−, HCO3−, SO42−, and NO3−), in accordance with the World Health Organization's (WHO 2017) standards. The results show that the water requires treatment of (Cl−) and (SO42−) before human consumption and that it is suitable for irrigation purposes based on parameters like Na% and SAR. The use of remote sensing via the application of the normalized difference water index (NDWI) on a series of six satellite images from the Thematic Mapper (TM) and Operational Land Imager (OLI) instruments shows an increase in surface water between 2006 and 2016 following the commissioning of two large dams (Zerrar and Igouzoullene). Beyond 2016, a drop in water surfaces estimated at around 5 km2 occurred.