It is important to make an assessment of quality for the best use of water resources distribution and utilization. It becomes necessary to have an idea of the present and future demand of water for various use e.g. irrigation, industries, public health and river conservation. In the present study an attempt has been made to evaluate water quality of Cauvery River around Krishna Raja Sagar (KRS) Dam for a period of one year. In order to evaluate the quality of Cauvery River, water samples were collected from different locations in various seasons during 2011 -12. Analysis of sediment reveals that the Cauvery River water is contaminated by certain Heavy metals with organic load. Concentrations of all metals increase in the downstream. Concentration of Heavy metals in sediments was in the order of Fe>Ni>Zn>Pb>Cu>Cr. Cr concentration exceeded the upper limit of standards. Increase of metal concentration indicate an increase in the pollution load due to application of fertilizers in the agricultural fields, ashes generated by the agricultural land and industries, industrial effluents and anthropogenic activities and discharge of wastes to the River. It was observed that the impact of human activity was severe on most of the parameters. It was observed that the main cause of deterioration in water quality was due to the lack of proper sanitation, unprotected river sites and high anthropogenic activities.