The groundwater of Bouhmama shows important chemical variations induced by the aridity of the climate, mineral dissolution and agricultural activity. The use of geochemical techniques has identified that the evolution of the chemical facies takes place from the calcium bicarbonate pole in the limestone outcrops in the West towards a major facies of calcium sulfate type in the center and downstream of the plain. These chemical facies are determined by the water-rock interaction, dissolution and mineral precipitations, through cationic exchanges along the water flow towards its outlet and the infiltration of irrigation waters loaded with salts and fertilizers in the irrigated perimeters. PCA (Principal Component Analysis) explaining 85.64% of the variance shows that except for bicarbonates all elements are responsible for the mineralization of groundwater.