Surface water has become one of the most vulnerable resources on the earth due to the deterioration of its quality from diverse sources of pollution. Understanding the spatiotemporal distribution of pollutants and identification of the sources in the river systems is a prerequisite for the protection and sustainable utilization of water resources. In order to check the quality of Wuseta River, water quality parameters such as; water temperature, pH, electrical conductivity, turbidity, total dissolved solids (TDS), phosphate, nitrate, dissolved oxygen(DO), five day biochemical oxygen demand(BOD5), total Hardness, chloride, sulphates and total coliform were examined from the six water sample points and the minimum and maximum value were distinguished as 20.2 and 22.2°C; 6.8 and 7.6; 100 and 750 µS/cm; 10.6 and 200NTU; 65 and 526.7; 0.1 and 6mg/l; 1 and 4.2mg/l; 2.1 and 8.7mg/l;10 and 95mg/l; 24.3 and 200mg/l 8 and 36mg/l; 0 and 72mg/l; 3500 and 92000CFU respectively. Principal component analysis (PCA) was utilized to identify the most significant water quality parameters and the probable source of the pollutants. The statistical analysis result from PCA/factor analysis (FA ) shows conductivity, TDS, DO, BOD5, and temperature are major factors that bring variation in water quality in the area. Based on National Sanitation Foundation Water Quality Index (NSFWQI) results, the river has good to medium quality. Generally, the observation, significant variables concentrations, water sample laboratory results, and interview results proved that the river has been polluted by all forms of human intervention, domestic animal excreta, agricultural activities, and different household wastes. Keywords: Water quality, Multivariate statistical analysis, principal component analysis, cluster analysis, Water Quality Index