Water pollution is a major environmental problem due to rapid population growth that over exploit and pollute the water resources. In this work the physico-chemical study of Asejire and Eleyele reservoirs are carried out to examine the water pollution levels. Eleyele and Asejire reservoirs are the two major sources of pipe-borne water in Ibadan with a population of about four million people. Water samples were collected from both sites from January 2003-December 2007 and analysed for 13 physico-chemical parameters. The data were subjected to Principal Component Analysis (PCA) to define the parameters responsible for the main variability in water pollution. The PCA produces 5 significant main components explaining 66.6% and 69.8% variance in Asejire and Eleyele reservoir, respectively. Generalized Linear Model (GLM) is applied to study the variability in turbidity level which shows that four parameters in each reservoir are important to explain the turbidity variation. Also many parameters in Asejire lie within the SON and WHO permissible limits while in Eleyele reservoir many parameters lie out. This therefore is an indication that water in Eleyele reservoir is more polluted than in Asejire reservoir.