Rivers have always been important for human beings, with the most important civilizations starting and flourishing on the banks of rivers. It's importance in the Indian civilization is very clear by the fact that the Hindus have worshipped the rivers. The mighty Ganga has been the most revered and worshipped river which has been supporting life in a large part of the country. It is still part of daily lives of millions who take a dip in the river as a daily routine. But the river's cleansing power has limited to spiritual feeling, I guess, as the Indians have been unconcerned about the filth that the Ganga is forced to carry. I won't be surprised if, in future, some kid, while crossing a bridge on the Ganga, mistakes it for a huge sewer, like the Yamuna in Delhi.