The Ganga System

The Ganga is the most important river of India, both because of the size of its basin and its cultural significance. It rises in the Gangotri glacier near Gaumukh, at an elevation of 3,900 metres, in the Uttarkashi district of Uttarakhand. At this point it is known as the Bhagirathi. The river cuts through the Central and the Lesser Himalayas in narrow gorges. At Devprayag, the Bhagirathi meets the Alaknanda, and from this confluence onward the combined stream is known as the Ganga.

The Alaknanda itself has its source in the Satopanth glacier above Badrinath. It is formed by the Dhauli and the Vishnu Ganga, which meet at Joshimath, also called Vishnu Prayag. Several other tributaries join the Alaknanda at points named for these confluences: the Pindar joins at Karna Prayag, while the Mandakini, also known as the Kali Ganga, meets it at Rudra Prayag.

The Ganga enters the plains at Haridwar. From there it flows first southward, then to the south-east and east, before splitting into two distributaries, the Bhagirathi and the Padma. The total length of the river is 2,525 km. Within India, it is shared by Uttarakhand (110 km), Uttar Pradesh (1,450 km), Bihar (445 km) and West Bengal (520 km). The Ganga basin covers about 8.6 lakh square kilometres in India alone, making the Ganga river system the largest in the country. It includes a number of perennial rivers originating in the Himalayas in the north and non-perennial rivers originating in the Peninsula in the south. The Son is its major right bank tributary, while the important left bank tributaries are the Ramganga, the Gomati, the Ghaghara, the Gandak, the Kosi and the Mahananda. The river finally discharges into the Bay of Bengal near Sagar Island.

The Yamuna is the westernmost and the longest tributary of the Ganga. It has its source in the Yamunotri glacier on the western slopes of the Banderpunch range, at 6,316 metres. It joins the Ganga at Prayag, formerly known as Allahabad. On its right bank, the Yamuna is joined by the Chambal, the Sind, the Betwa and the Ken, all of which originate in the Peninsular plateau. On its left bank it is joined by the Hindan, the Rind, the Sengar and the Varuna. Much of the Yamuna's water feeds the western and eastern Yamuna canals and the Agra canals for irrigation purposes. The states drained by the Yamuna include Uttarakhand, Himachal Pradesh, Haryana, Delhi and Uttar Pradesh.

The Chambal rises near Mhow in the Malwa plateau of Madhya Pradesh and flows northwards through a gorge upstream of Kota in Rajasthan, where the Gandhisagar dam has been constructed. From Kota it traverses down to Bundi, Sawai Madhopur and Dholpur, and finally joins the Yamuna. The Chambal is famous for its badland topography, known as the Chambal ravines.

The Gandak comprises two streams, the Kaligandak and the Trishulganga. It rises in the Nepal Himalayas between the Dhaulagiri and Mount Everest and drains the central part of Nepal. It enters the Ganga plain in the Champaran district of Bihar and joins the Ganga at Sonpur, near Patna.

The Ghaghara originates in the glaciers of Mapchachungo. After collecting the waters of its tributaries — the Tila, the Seti and the Beri — it comes out of the mountain, cutting a deep gorge at Shishapani. The river Sarda, also called the Kali or Kali Ganga, joins it in the plain before the Ghaghara finally meets the Ganga at Chhapra.

The Kosi is an antecedent river with its source to the north of Mount Everest in Tibet, where its main stream, the Arun, rises. After crossing the Central Himalayas in Nepal, it is joined by the Son Kosi from the west and the Tamur Kosi from the east. It forms the Sapt Kosi after uniting with the river Arun.

The Ramganga is a comparatively small river rising in the Garhwal hills near Gairsain. After crossing the Shiwalik, it changes its course to the southwest direction and enters the plains of Uttar Pradesh near Najibabad. Finally, it joins the Ganga near Kannauj. …