ORIGINATING IN TIBET and flowing 1,557 mi (2,507 km) from northwest to southeast through INDIA, the Ganges River empties into the BAY OF BENGAL. Known as the Ganga in India, it is the most important river in South Asia, sustaining the lives of literally hundreds of millions of people daily. Along with its sister river the INDUS, the two create the broad and densely populated Indo-Gangetic Plain that stretches in a great arc from the ARABIAN SEA, along the Himalayan foothills to the Bay of Bengal. The divide between the two great river complexes is a mere 300 ft (91 m) in elevation.
The early civilizations that were born on the banks of the Indus moved easily across to the waters and fertile lands of the Ganges. The great literary traditions of oral hymns of the Vedas tell of the conquest and settlement of the Ganges by Aryan-speaking migrants. The Ganges has always been a primal and spiritual force to the millions who have lived along its banks across the millennia of history. Still today, the Ganges is the holiest of rivers in the Hindu tradition, and the faithful flock to it for spiritual cleansing and healing.
The Ganges is a goddess, Ganga devi, one of the two daughters of Meru (the HIMALAYAS). The river is honored in the ancient Vedas and in the two great epic poems, the Ramayana and the Mahabharata. Even the Lord Vishnu bathed in these holy waters that wash away all sins. Great annual festivals bring massive crowds to sacred sites along the Ganges and especially during the Melas that occur every few years on auspicious dates. The waters of the river are considered immaculate, and any amount can purify people, places, and objects.
The Ganges River basin covers almost 25 percent of India's area. The Himalayas bound it to the north and the Vindhya Range in the south. The Ganges has its source from the huge and ancient glaciers of the Himalayas. Fittingly, the three great rivers of South Asia, the Indus, the Brahmaputra, and the Ganges all have their source fairly close together in the Himalayan foothills. The Indus winds down into KASHMIR and on through the Punjab and Sind to the Arabian Sea. The Brahmaputra journeys to the north on a long journey in Tibet only to join the Ganges far downstream in BANGLADESH and strengthen its rush to the sea. In the northern part of the Ganga River basin, practically all of the tributaries of the Ganga are perennial streams being fed by the snowmelt of the Himalayan Mountains. However, in the southern part of the catchment basin, located in the states of Rajasthan and Madhya Pradesh, many of the tributaries have significant flows only during the monsoon months of June through September. It is during these times the Ganges is most prone to flooding.
The Yamuna, the principle tributary to the Ganga in India, originates less than 100 mi (62 km) east of the source of the Ganges. It flows to the south and almost parallel to the Ganges for most of its 870 mi (1,400 km) course. They join at the holy city of Allahabad, where they are said to converge with the mythic Saraswati River creating a site of pilgrimage for Hindus. Other major rivers that bring the waters of the Himalayas down to the Ganga are the Ghaghara, which joins near Chhapra in Bihar, and the Gandak, which comes in near Patna.
Within the borders of Bangladesh, the Ganges meets the Brahmaputra (called Jamuna in Bangladesh) and greatly increases in volume. Here the Ganges takes on the name Padma as it continues, creating one of the world's largest river deltas. The Padma splits into innumerable watercourses that are known as the Mouths of the Ganges as they spill into the Bay of Bengal.
Pollution by growing population pressure is the river's greatest challenge. Over 380 million humans live within its catchment basin. Little public sanitation exists to deal with the sewage that is generated. Industrial effluents, many toxic, grow in volume with continued economic development.
Water volumes of the Ganges and its many tributaries can drop significantly during the dry period of the annual monsoon cycle. Lands that are flooded in the wet season must be irrigated by tube well during the dry season, as all arable land must be worked to support such a large population.