In order to characterize the groundwater of the Poro region and to apprehend the phenomena at the origin of their mineralization, physicochemical analyzes were carried out on 124 water samples. The descriptive analysis of physicochemical parameters showed that the waters are acidic and weakly mineralized overall. The levels of manganese and iron are sometimes very high and above the drinking water standard WHO drinking water. The Piper diagram revealed that the waters are approximately 98% calcium carbonate and calcium sulphate chlorinated carbonate at 2%. The Principal Component Analysis (PCA) has highlighted two major phenomena in the acquisition of mineralization of water. The main phenomenon is the dissolution of the rock by the water-rock contact and the second is related to the inflow of water by superficial infiltration. Overall, the groundwater in the study area is of good quality. Very few nitrates have been detected and the measured concentrations are well below the drinking water guideline. Concentrations of manganese and iron sometimes exceed the aesthetic criteria and could be a concern for the health of children.