The Ganges is a trans-boundary river of Asia which flows through India and Bangladesh. The 2,525 km (1,569 mi) river rises in the western Himalayas in the Indian state of Uttarakhand. It flows south and east through the Gangetic plain of North India, receiving the right-bank tributary, the Yamuna, which also rises in the western Indian Himalayas, and several left-bank tributaries from Nepal that account for the bulk of its flow. In West Bengal state, India, a feeder canal taking off from its right bank diverts 50% of its flow southwards, artificially connecting it to the Hooghly River. The Ganges continues into Bangladesh, its name changing to the Padma. It is then joined by the Jamuna, the lower stream of the Brahmaputra, and eventually the Meghna, forming the major estuary of the Ganges Delta, and emptying into the Bay of Bengal. The Ganges–Brahmaputra–Meghna system is the second-largest river on earth by discharge.
Nepal measures about 880 kilometers (547 mi) along its Himalayan axis by 150 to 250 kilometers across. It has an area of 147,516 km2 (56,956 sq mi).
The Yamuna is the second-largest tributary river of the Ganges by discharge and the longest tributary in India. Originating from the Yamunotri Glacier at a height of about 4,500 m (14,800 ft) on the southwestern slopes of Bandarpunch peaks of the Lower Himalaya in Uttarakhand, it travels 1,376 kilometres (855 mi) and has a drainage system of 366,223 square kilometres (141,399 sq mi), 40.2% of the entire Ganges Basin. It merges with the Ganges at Triveni Sangam, Prayagraj, which is a site of the Kumbh Mela, a Hindu festival held every 12 years.
The Mahananda is a trans-boundary river that flows through the Indian states of Bihar and West Bengal before crossing into Bangladesh. It is an important tributary of the Ganges.
The Chambal River is a tributary of the Yamuna River in Central and Northern India, and thus forms part of the drainage system of the Ganges. The river flows north-northeast through Madhya Pradesh, running for a time through Rajasthan, then forming the boundary between Rajasthan and Madhya Pradesh before turning southeast to join the Yamuna in Uttar Pradesh state.
The Ganges Basin is a major part of the Ganges-Brahmaputra-Meghna (GBM) basin draining 1,999,000 square kilometres in Tibet, Nepal, India and Bangladesh. To the north, the Himalaya or lower parallel ranges beyond form the Ganges-Brahmaputra divide. On the west the Ganges Basin borders the Indus basin and then the Aravalli ridge. Southern limits are the Vindhyas and Chota Nagpur Plateau. On the east the Ganges merges with the Brahmaputra through a complex system of common distributaries into the Bay of Bengal. Its catchment lies in the states of Uttar Pradesh (294,364 km2), Madhya Pradesh (198,962 km2), Bihar (143,961 km2), Rajasthan (112,490 km2), West Bengal (71,485 km2), Haryana (34,341 km2), Himachal Pradesh (4,317 km2), Delhi, Arunachal Pradesh (1,484 km2), the whole of Bangladesh, Nepal and Bhutan. Several tributaries rise inside Tibet before flowing south through Nepal. The basin has a population of more than 500 million, making it the most populated river basin in the world.
The Gandaki River, also known as the Narayani and Gandak, is one of the major rivers in Nepal and a left-bank tributary of the Ganges in India. Its total catchment area is 46,300 km2 (17,900 sq mi), most of it in Nepal. In the Nepal Himalayas, the Gandaki is notable for its deep canyon. The basin also contains three mountains over 8,000 m (26,000 ft), namely Dhaulagiri, Manaslu and Annapurna Massif. Dhaulagiri is the highest point of the Gandaki basin.
The Burhi Gandak River is a tributary of the Ganges. It is also known as the Sikrahna river. The Burhi (“Old”) Gandak flows parallel to and east of the Gandak River in an old channel.
The Kosi or Koshi is a transboundary river which flows through China, Nepal and India. It drains the northern slopes of the Himalayas in Tibet and the southern slopes in Nepal. From a major confluence of tributaries north of the Chatra Gorge onwards, the Kosi River is also known as the Saptakoshi for its seven upper tributaries. These include the Tamur River originating from the Kanchenjunga area in the east and Arun River and the Sun Kosi from Tibet. The Sun Koshi's tributaries from east to west are the Dudh Koshi, Likhu Khola, Tamakoshi River, Bhote Koshi and Indravati. The Saptakoshi crosses into northern Bihar, India where it branches into distributaries before joining the Ganges near Kursela in Katihar district. The Kosi is the third-largest tributary of the Ganges by water discharge after the Ghaghara and the Yamuna.
The Seti River is an important tributary of the Karnali river system that drains western Nepal.
The ongoing pollution of the Ganges, the largest river in the Indian subcontinent, poses a significant threat to human health and the environment. The river provides water to about 40% of India's population across 11 states. It serves an estimated population of 500 million people, more than any other river in the world.
Bihar is located in the eastern region of India, between latitudes 24°20'10"N and 27°31'15"N and longitudes 83°19'50"E and 88°17'40"E. It is an entirely land–locked state, in a subtropical region of the temperate zone. Bihar lies between the humid West Bengal in the east and the sub humid Uttar Pradesh in the west, which provides it with a transitional position in respect of climate, economy and culture. It is bounded by Nepal in the north and by Jharkhand in the south. Bihar plain is divided into two unequal halves by the river Ganges which flows through the middle from west to east. Bihar's land has average elevation above sea level of 173 feet.
Bihar is India's most flood-prone state, with 76% of the population of North Bihar living under the recurring threat of devastating flooding. Bihar makes up 16.5% of India's flood-affected area and contains 22.1% of India's flood-affected population. About 73.06% of Bihar's geographical area, 68,800 square kilometres (26,600 sq mi) out of 94,160 square kilometres (36,360 sq mi), is affected. Each year, floods kill many and damage livestock and other assets worth millions. In total, floods have claimed 9,500 lives since the government started publishing figures in 1979. North Bihar districts are vulnerable to at least five major flood-causing rivers during monsoon – the Mahananda, Koshi, Bagmati, Burhi Gandak, and Gandak rivers – which originate in Nepal. Some South Bihar districts have also become vulnerable to floods, from the Son, Punpun, and Phalgu rivers. The 2013 flood affected over 5.9 million people in 3,768 villages in 20 districts in the state. The 2017 flood affected 19 districts in North Bihar, killing 514 people and affecting over 17 million.
The Sharda River, also called Kali River and Mahakali River, originates at [Limpiyadhura] in the Himalayas at an elevation of 3,600 m (11,800 ft) in the Darchula district in Sudurpaschim, Nepal. It flows along Nepal's western border with India and has a basin area of 14,871 km2 (5,742 sq mi). It joins the Ghaghra River, a tributary of the Ganges. It takes the name Kali River from the union of the two streams at Gunji as it flows through the hills. After Brahmadev Mandi near Tanakpur, it enters the Terai plains, where it is called the Sharda River.
The Punpun River is a tributary of the Ganges. It originates in Palamu district of Jharkhand and flows through Chatra, Aurangabad, Gaya and Patna districts of the Indian states of Jharkhand and Bihar. Punpun is a place named after the Punpun river in Patna which is situated on the bank of Punpun river. On the bank of Punpun people celebrate Chhath Puja.
The Kamala River originates in Nepal and flows through the Indian state of Bihar.
The West Rapti, also known as the Kuwano, is a river which drains Rapti Zone in Mid-Western Region, Nepal, then Awadh and Bhojpur-Purvanchal regions of Uttar Pradesh state, and finally India before joining the Ghaghara. It is a major left bank tributary of the Ganges, and is also known as the Karnali in Nepal.
The Babai River originates in and completely drains Inner Terai Dang Valley of Mid-Western Nepal. Dang is an oval valley between the Mahabharat Range and Siwalik Hills in its eponymous district. Dang was anciently home to indigenous Tharu people and came to be ruled from India by the House of Tulsipur who also counted as one of the Baise Rajya —a confederation of 22 petty kingdoms in the Karnali (Ghagra) region. About 1760 AD all these kingdoms were annexed by the Shah Dynasty during the unification of Nepal, except Tulsipur lands south of the Siwalik Hills were not taken. Since Dang Valley was somewhat higher, cooler, better-drained and therefore less malarial than most of the country's Inner Terai, it was settled to some extent by Shah and Rana courtiers and other Paharis long before DDT was introduced to control the disease-bearing Anopheles mosquito.
The Lower Sharda Barrage, is a dam nearly 28 km from Lakhimpur city in Uttar Pradesh, India.
