While industries and urbanisation have brought about significant deterioration in the water quality of rivers and lakes across the country, an aspect that often stays concealed is the role of cultural activities in contributing to this degradation. Delhi is dependent on the river Yamuna, the second largest tributary of the Ganga, for its domestic, industrial and agricultural needs. Yamuna, being one of the sacred rivers in the country, is often the site of rituals and rites. Last rites of the dead are often performed at its banks, and the practice of immersion of idols is among the major reasons why the river is so polluted.