The region of Tadjenanet is in eastern Algeria in the high plains, characterized by a varied age detritus Mio-Plio-Quaternary. Some geological formations can be an important source of groundwater (alluvial sand, shell limestone, gravel). Its location in semi-arid area involves evaporation pronounced even tilt the balance in a chronic deficit, excluding periods characterized by rainfall events. Agriculture in the study area is the first socio-economic activity and the largest consumer of water resources. It is therefore necessary to consider for effective water management. Indeed, the combination of hydrogeological and hydro chemical geological mapping, geophysics, harvested from field data and their interpretations can be an excellent tool for deciding the suitability of water for irrigation. The analysis of the physicochemical data shows an increase in the concentration of nitrates reaching 200 mg · l–1, as well as the analysis by the Richards SAR parameter shows that most groundwater samples are generally suitable for agricultural purposes with 33%, belong characterizing poor quality. Indeed, the groundwater in the region generally requires prior treatment before consumption and use depending on the type of crop. The assessment of the quality of the water in the region and its consequences on the soil and the types of crops has enabled the authorities concerned to manage the water supply adequately to preserve and protect this vital source for the future from any risk of contamination.