Rivers of Bihar (with Map)

• Bihar has an area of 3.82 lakh hectares of water, which is 4.1 per cent of the total geographical area of the state.
• Bihar is located in the eastern part of India which is in the central portion of the Indo-Gangetic plain and is bounded by the Himalayas from the north and the plateau from the south which is the source of the entire river flowing here.
• Although an entirely landlocked state, Bihar is very rich in water resources, both ground and surface water resources. The rivers of Bihar form the major source of surface water resources. 

Rivers of Bihar

• Bihar is a completely agriculture-based state, and here the rivers play an important role in making the economy of the state.
• This state is endowed with many places with many seasonal and perennial rivers. These form the source of surface water in this state.
• Some of the northern and southern alluvial state tracts have the availability of water throughout the seasons. The Ganga River separates this state into two unequal parts. Additionally, the rivers of Bihar are split into two groups based on where they are located, namely the rivers of the South Rivers of Bihar and the North Rivers of Bihar.

Northern Bihar Rivers

• The plains of Bihar are segregated into two sections by the River Ganga according to the Bihar River Map.
• The alluvial plain lying to the north of the Ganga River is termed as the North Plains of Bihar.
• This region is bestowed with a range of rivers, labeled as the Northern Rivers in Bihar.
• Seasonal as well as perennial rivers contribute to the rich water resources of these plains.
• Key rivers flowing into the Ganga in this region include but are not limited to, the Burhi Gandak, Gnadak, Mahananda, Kosi, and Ghaghra.
• Certain rivers like Kamla-Balan and Bagmati-Adhwara follow a course where they first converge into the river Kosi and subsequently flow into the River Ganga.
• These rivers in Bihar are based in the Himalayas, a geographical location shared between Tibet and Nepal.
• During the monsoon, the water levels in these northern rivers in Bihar tend to rise, with precipitation increasing up to 80 times the average levels.
• The process of changing river courses has given birth to Ox-bow lakes, locally known as Chairs in this region.

Southern Bihar Rivers

• Southern Bihar’s plains feature diverse tracts that are enriched by rivers such as the Kiul, Sone, Badua Chandan, and Karmnasa, all of which feed into the Ganga river.
• The rivers in Bihar at the southern plains primarily have their origins in either the Vindhyachal hills or the Chhotanagpur or Rajmahal hills.
• The land drainage along the southern bank of the Ganga river is hindered by leaf-like obstructions.
• Distinct land formations, known as ‘Tal’ or low-lying areas, prominently mark the southern plains, a feature owing to the unique courses of the various rivers.

List of Rivers of Bihar

Name of Basin	Total Catchment Area (Sq.km)	Catchment in Bihar (Sq Km)	Name of Main River	Length of Main River in Bihar (Km)
Ghaghra	127950	2995	Ghaghra	83
Gandak	40553	4188	Gandak	260
Burhi Gandak	12021	9601	Burhi Gandak	320
Bagmati-Adhwara	14384	6500	Bagmati	394
Kamla-Balan	7232	4488	Kamla	120
Kosi	74030	11410	Kosi	260
Mahananda	23700	6150	Mahananda	376
Main Ganga Stem	136970	16205	Ganga	445
Karmnasa	7792	5127	Karmnasa	24 76 km (forms Common boundary between Bihar and UP)
Son	70228	1483	Son	202
Punpun	9026	7536	Punpun	235
Kiul-Harohar	17225	12806	Kiul	41
Badua	2215	2215	Badua	130
Chandan	4093	2371	Chandan	118

List of Rivers of Bihar	Origin	Seasonality
Ghaghra	Tibet	Perennial
Kosi	Tibet	Perennial
Son	Amarkantak, MP	Perennial
Gandak	Tibet	Perennial
Bagmati	Nepal	Perennial
Mahananda	Darjeeling	Perennial
Burhi Gandak	Chanpatia	Perennial
Kamla	Nepal	Perennial
Ganga Stem	Gangotri, Uttarakhand	Perennial
Harohar	Jharkhand	Seasonal
Punpun	Palamau, Jharkhand	Seasonal
Karamnasa	Kaimur	Seasonal
Chandan	Deoghar	Seasonal
Kiul	Khajuri, Jharkhand	Seasonal
Badua	Chakia Plateau	Seasonal

Major Rivers of Bihar (with important details)

Ghaghra River

• The Ghaghara originates in the glaciers of Mapchachungo. Alternatively known as Karnali or Kauriala, it is a trans-boundary perennial river originating from the Tibetan plateau near Lake Mansarovar.
• It cuts through the Himalayas in Nepal and is joined by the Sharda River at Brahmaghat in India
• It is a major left-bank tributary of the Ganga and joins it at Chhapra in Bihar.
• The Ghaghra river basin has a total catchment area of 1,27,950 Sq Km, of which the area lying in Bihar is 2995 Sq Km, the rest 70,303 Sq Km being in Nepal and 54,652 Sq km in UP.
• Sixteen districts of UP and three districts namely Gopalganj, Siwan and Chapra of Bihar are covered by the catchment of this basin in India.
• Nearly the entire plains of the catchment lie below the south of the Indo-Nepal border line in India. This forms part of the alluvial Gangetic plains.
• In Bihar State, the tributaries such as the Little Gandak, the Jharahi and the Daha joining the Ghaghra on its left bank flow through silted cross sections.
• There are also some low-lying lands called ‘Chaurs’ which remain submerged for a considerable period due to drainage congestion.

Gandak River

• It is formed by the union of the Kali and Trisuli rivers, which rise in the Great Himalayan Range in Nepal. From this junction to the Indian border the river is called the Narayani
• It enters the Ganga river opposite Patna in a place called Sonepur after a winding course of 765 km
• The Burhi Gandak flows parallel to and east of the Gandak River
• The upper catchment area of the river is bleak and desolate lying in the rain shadow area of the Himalayan range
• The middle and the lower courses of the river flows through the V-shaped valleys, incised meanders, and have paired and unpaired terraces on either sides.
• The total catchment area of the Gandak river basin upto its outfall into the Ganga is 40,553 Sq Km of which- 4,188 Sq Km lie in Bihar, 895 Sq Km lies in UP and the rest 35,470 Sq Km lies in Nepal.
• The basin is roughly trapezoidal in shape up to Valmiki Nagar. The river has a very steep slope in the mountains but after it debouches into the plains, the slope gradually becomes flatter.
• Like other rivers of North Bihar, it also brings an enormous quantity of sediment load along with its flow during the monsoon period.
• The river Gandak flows more or less on the ridge line and therefore, any breach in the banks causes great devastations. The problem of flooding gets ‘further aggravated when the Ganga is also in flood simultaneously and the outfall of the river Gandak is choked resulting in backflow of the Ganga into the Gandak.
• The river has been embanked on both banks and the problem is one of proper maintenance of these embankments. Any breach in the embankment, therefore, results in catastrophe in the area.

Burhi Gandak River

• This 320km long river originates from Chautarva Chaur near Bisambharpur in the district of West Champaran district of Bihar
• It initially flows through the East Champaran district.
• After flowing for a distance of about 56km the river takes a southerly turn where two rivers – the Dubhara and the Tour- join it.
• Thereafter, the river flows in a south-easterly direction through the Muzaffarpur district for about 32km.
• It flows parallel to and east of the Gandak River in an old channel.
• The main tributaries of the Burhi Gandak are – Masan, Balor, Pandai, Sikta, Tilawe, Tiur, Dhanauti, Kohra, and Danda.
• Samastipur is situated on it.
• There is no major or medium project over the Burhi Gandak river system.
• The catchment area of the Burhi Gandak is 12,021 Sq Km out of which 2420 Sq Km of the hilly catchment lies in Nepal and the rest 9601 Sq Km lies in Bihar. The catchment is fan-shaped up to the confluence of the Dhanauti and thereafter its shape is elongated, narrow and rectangular. 
• The Burhi Gandak river basin is bounded by the Someshwar range of hills in the north, the Bagmati basin in the east, the Gandak river basin in the west and the main Ganga stem in the south.
• The sediment brought by Burhi Gandak river formed inland deltas where the steep slope of terai converged into the flat slope of the plains. This resulted in the meandering and braiding tendencies in the river leading to shifting of courses. Such changes in the river course and avulsions and cut-offs of the meander loops formed local depressions known as Mauns.

Bagmati River

• It is a transboundary river between Nepal and India.
• It rises in the Shivapuri Hills to the north of Kathmandu and flows southward through the city.
• It passes across the Kathmandu Valley, which is situated in Nepal.
• It gets divided from Kathmandu through Patan, passing via Province No. 2 of the Southern region of Nepal that eventually seeps into the Bihar state of India.
• This river is assumed to be sacred by a pair of religions, Hindus as well as Buddhists. 
• Major tributaries – Bishnumati, Manohara, Hanumante, Dhobikhola and Tukucha.
• The River ultimately joins the Narayani River, located in southern Nepal.
• The merged waters of the Bagmati and Narayani eventually make their way southward and into the Ganges.
• During floods the rivers of the basin spill over its banks and inundate large part of lands in the district of Sitamarhi, East Champaran, Muzaffarpur, Darbhanga, Samastipur and Khagaria.

Kosi River

• Aka Saptakoshi for its 7 Himalayan tributaries, it is an antecedent transboundary river flowing through Nepal and India
• Some of the rivers of the Kosi system, such as the Arun, the Sun Kosi, and the Bhote Koshi, originate in the Tibet
• This 729km long river is one of the largest tributaries of the Ganga and joins it at Kursela in Kathiar district
• The highest peak in the world, Mt.Everest and the Kanchenjunga are in the Kosi catchment.
• Bagmati is an important tributary of the Kosi.
• Over the last 250 years, the Kosi river has shifted its course over 120km from east to west
• Its unstable nature has been attributed to the heavy silt it carries during the monsoon season, Due to this, it is also termed as “The Sorrow of Bihar”.
• The Kosi drains a total catchment area of 74030 Sq Km out of which only 11410 Sq Km lies in India and the rest 62620 Sq Km lies in Tibet and Nepal.
• It is a snowfed river and hence perennial. The catchment area falling within Indian territory is distributed under several districts of Bihar namely –
  • Madhubani
  • Darbhanga
  • Saharsa
  • Supaul
  • Madhepura
  • Araria
  • Purnea
  • Katihar
  • Bhagalpur
  • Khagaria
• The districts on the left bank of the river Kosi are flood prone
  • Supaul
  • Saharsa
  • Madhepura
  • Araria
  • Purnia
  • Katihar
• The districts on the right bank of the river Kosi are flood prone
  • Madhubani
  • Darbhanga
  • Khagaria

Mahananda River

• 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 Mahananda river system consists of two streams- one is locally known as Fulahar river and the other Mahananda.
  • The Fulahar originates in the Himalayas in Nepal and traverses through the Indian state of Bihar and merges with the Ganges in left opposite to Rajmahal.
  • The Mahananda originates in the Himalayas: Paglajhora Falls on Mahaldiram Hill near Chimli, east of Kurseong in Darjeeling district at an elevation of 2,100 metres.
    • It flows through Mahananda Wildlife Sanctuary and descends to the plains near Siliguri.
    • It touches Jalpaiguri district.
• It joins the Ganges at Godagiri in Nawabganj district in Bangladesh.

Karmnasa River

• The Karmanasa River is a tributary of the Ganges.
• It originates in Kaimur district of Bihar and flows through the Indian states of Uttar Pradesh and Bihar.
  • The Karamnasa rises near Sarodag on the northern face of the Kaimur range about 29 km west of Rohtasgarh in Mirzapur district of UP at an elevation of 350m and forms a boundary between Bihar and UP from the point River Gurwat joins Karamnasa.
  • Then it flows through Varanasi district in UP and finally falls in Ganga near Chausa.
• The Total geographical area of the basin is 5127 sq km. The total length of the river is 192 km of which 92 km lies in UP, 24 km in Bihar and balance 76 km forms the common-boundary between Bihar and UP.
• Its tributaries are the Durgavati, the Chandraprabha, the Karunuti, the Nadi, the Goriya and the Khajuri.

Son River

• The Son, 784km long, originates near Amarkantak in MP, just east of the headwater of the Narmada River, and flows north-northwest through MP before turning sharply eastward where it encounters the southwest-northeast running Kaimur Range
• The Son parallels the Kaimur hills, flowing east-northeast through UP, Jharkhand, and Bihar states to join the Ganga just above Patna.
• Geologically, The lower valley of the Son is an extension of the Narmada Valley, and the Kaimur Range an extension of the Vindhya Range.
• It is the Ganga’s longest south bank tributary, at 760 km.
• Dehri is the major town situated on Son River.
• Tributaries of Son river
  • Right – Gopad Rive, Rihand River, Kanhar River, North Koel River
  • Left – Ghaggar River, Johila River, Chhoti Mahanadi River
• Its chief tributaries are the Rihand and the North Koel. It is largely forested and sparsely populated.

Punpun River

• It originates in the Palamu district of Jharkhand.
• It flows through Chhatra, Aurangabad, Gaya, and Patna of both Jharkhand and Bihar.
• It flows in the north-east direction and joins the Ganga at Fatuha, Patna, Bihar.
• River Punpun is mentioned in the Padma Puranas, and Vayu is connected to Gaya Mahatmya.
• The Punpun basin drains a total catchment area of 9026 Sq Km lies in Bihar and Jharkhand and 7536 Sq.Km in Bihar. The catchment covers the districts of Patna, Jahanabad, Gaya, Aurangabad.
• Due to low bank and inadequate channel capacity, all the channels in the lower reaches spill heavily over their banks even during norinal floods.
• Spilling is more acute on both banks of the Punpun north of Jahanabad-Kinjer road. The spill of the Punpun after flowing north-eastwards meets the spills of its’ two. tributaries the Morhar and the Dardha.

Kiul River

• It originates in the Giridih district of Jharkhand, India.
• It flows through the Sheikhpura, Jamui, and Lakhisarai, districts of the Indian state of Bihar before joining the Ganges near Surajgarha, Bihar.
• It is 110 kilometres long and covers an area of about 16,500 square kilometres.
• The Kiul-Harohar river system drains an area of 17225 Sq Km in Bihar and Jharkhand and 12806 Sq.Km in Bihar as per GIS. The upper catchment of the river system lies in Chotanagpur plateau area which is characterised by low hills and slopes with depressions and valleys.

Chandan River

• It is a significant river that flows near the city of Bhagalpur in the Indian state of Bihar. The river is also known by the name of Champa River, which has been identified as the historical name of the river.
• The basin is drained independently by the river Chandan and the chir. The river Bilasi runs almost parallel to the Chandan river on its left and falls into Chandan which ultimately outfalls into the Ganga.
• The river originated from the hills of Deoghar in Jharkhand state at an elevation of 274 M and after travelling 110Km length bifurcates into number of small channels with deltaic river characteristic before meeting the river Ganga through Jamunia Nala.
• The important tributaries of Chandan are Orhni, Kuldar and Chatri.