Since ionic concentration in the lake influence the lake’s ability to assimilate pollutants and maintain nutrients in water, a detailed study on water quality was undertaken to get an insight on the natural and anthropogenic processes operating in Hussain Sagar Lake during idol immersion in September- 2007. The water samples were collected before and after the immersion of idols and were analyzed for various parameters. The analysis results indicate that water quality of lake- decline after the idol immersion along with other anthropogenic activities. For conservation of this lake, suitable methods are suggested like immersion of idols in artificial ponds and two-size idol system should be practice to retain the glory and pristine beauty of this lake.