Water provides for the basic essentialities of human existence. Water of good quality is essential for socioeconomic growth. Besides it also sustains various species of plants and animals by regulating their metabolic activities. Chemical, biological and physical characteristics of water define its quality for use. The lake is located on the banks of the Ponnaiyar River, about 6 km south-east of Hosur, close to the Hosur Krishnagiri road. The lake issituated on the other side of the reservoir. The water samples of Thorapalli lake were collected and analyzed for its physico chemical characteristics for the period from January 2018 to December 2018. The present study was undertaken to characterize the physicochemical parameters such as Temperature (T), pH, Total Alkalinity (TA), Electrical Conductivity (EC), phosphates, Nitrates, Total Hardness (TH), Dissolved oxygen (DO), Turbidity (TY), Total Dissolved Solids (TDS), Biochemical oxygen demand(BOD), and Chemical oxygen Demand(COD). Each parameter was compared with its standard permissible limit as prescribed by World Health Organization (WHO). The study reveals that few of the parameters have values beyond the desirable limit prescribed by WHO.