Recent investigations into the level of heavy metal enrichment in the water of Varal Devi Lake in Bhiwandi have indicated that significant contamination has occurred over the past few years. Elevated levels of Manganese have been observed in most parts of the lake causing toxicity. Current levels of manganese in the Varal Devi Lake water have arisen from natural sources and due to anthropogenic activities (Idol Immersion). These results reiterate the importance of identifying the causes of toxicity in assessments of water contamination. The results obtained were compared with standards prescribed by WHO (1993) and BIS (10500-1991). It was found that the concentration of heavy metal is above the water quality standards. The findings of the study revealed that the water quality degraded after the immersion of idols.