The lake is eutrophying fast and algal blooms and fish deaths are becoming common. Spread of macrovegetation is evident and 25% of the lake area is covered with Water Lilly - Nymphaea nouchali. The council has been campaigning for preventing the pollution that is entering the lake by subterranean drainage from hotels and restaurants built on the lake watershed.

The council conducts a Volunteer Water Quality Monitoring programme for educating School Students of Kodaikanal about water quality and reasons for the eutrophication of the lake. We need help in purchase of equipment for quicker water analysis. Our studies indicate that the oxygen levels are sometime as low as 4mg per litre. The oxygen level reaches the maximum during the monsoon rains of October- November, when it is about 11mg per litre.

Biological methods of monitoring based on bioindicators is being given priority as opposed to physical and chemical analysis. The Council is evolving an index for river purity based on macrobiological insects like Stoneflies; Caddis flies; Dobson flies.