The study area is found in the main rift valley of Ethiopia in which surface and groundwater are the main source for domestic and agricultur al purposes. The main objective of the study is to investigate the hydrochemistry and water quality of the area using graphical, multivariate and water quality analysis techniques. The spatial distribution of major cation and anions ions reveals in order of Na + > Ca 2+ and HCO 3 - > Cl - > SO 4 2- > F - > NO 3 - respectively. Na-HCO is the main hydrogeochemical facies resulting from deep rock-water interactions and long residence time. The principal component analysis shows that the first 3 factors explain 82.02% of the total variance of the hydrochemistry that shows hydrolysis of silicate minerals and to some extent, anthropogenic effects are the main factors that control groundwater chemistry. Water quality index values show the majority of the samples comprised very poor water (34.2%), distributed in the south-eastern parts of the study area, followed by excellent water (15.77%) in the western and good water (21.05%) in north western, north eastern and southern parts of the study area. The poor water types covers 21.05% and the remaing 8.10% is unfit water. The study result shows that the major drinking water quality problems in the area is fluorides concentration in which the values exceed the WHO standards with the average value of 8.3 mg/l . This water quality problem is high towards the discharge area with a parallel enrichment of F. In terms of irrigation water quality, the Sodium Absorption Ratio shows that the surface waters (Rivers) samples (SAR=2.57) were highly suitable for irrigation compare to groundwater with SAR value 22.4 . The sodium hazard versus salinity hazard of the entire surface water sample fall into category C 1 3 -S and shows very low electrical conductivity and sodium hazard index which is suitable for irrigation purpose The study result will be helpful for water managers and government offices to protect the local people from water quality problems,bone fluorosis and tooth decay on bones which is common in the area. Furthermore, This study, helps local farmers and agricultural activities in the extended rift valley farmlands. 1 > K + > Mg 2+