A woman washes clothes in the Ganges outside the site of the 2010 Kumbh Mela, the largest religious gathering in the world. Tens of millions take the pilgrimage to visit this festival that takes place in Allahabad, Haridwar, Ujjain and Nashik over the course of twelve years. The water that begins it's flow from the glaciers in the Himalaya and Tibetan plateau is a freshwater lifeline for nearly 20 percent of the Worlds population, almost 1,5 billion people. Around 18,000 glaciers store a massive 12,000 square kilometres of freshwater here. Together with snow-melt they contribute to the summer flow of Ganges and other major life giving rivers such as the Indus, Brahmaputra, Yangtze and Yellow Rivers.