Rivers and Drainage System | BPSC Preparation: All subjects - BPSC (Bihar) PDF Download

Rivers and Drainage System

Drainage refers to the flow of water through well-defined channels, while a drainage system is the network of such channels. Bihar is abundant in both ground water and surface water resources. It is bordered by the Himalayas to the north and a plateau to the south, which are the sources of all the rivers flowing through the state. Bihar receives water not only from rainfall but also from the rivers that flow within its territory.

• The physical topography of Bihar gives rise to trellis (grid) and dendritic drainage patterns. Many rivers flow through alluvial deposits where the slope is minimal, creating wide flood plains. 
• These rivers have large catchment areas and are crucial for irrigation, hydroelectric power generation, water transport, and providing fish for the fishery industry. Additionally, they enrich the state's natural resources in various ways. 
• Bihar also has an inexhaustible source of ground water, which is used for drinking, irrigation, and industrial purposes.

Major Rivers in Bihar

Rivers are a significant part of the geography of Bihar, and they play a vital role in the state’s economy. The river system in Bihar can be categorized based on the origin of the rivers and their drainage patterns. The two categories are:

Rivers Originating from Himalayas/North Ganga Plain

Origin and Characteristics

• These rivers originate from the Himalayas, located to the north of Bihar.
• They flow through the Northern plain regions, formed by the Ganges and its tributaries, and eventually drain into the Bay of Bengal, located to the southeast.

Major Rivers

• Ganga
• Ghaghara (Saryu)
• Gandak
• Burhi Gandak
• Kosi
• Kamla Balan
• Bagmati
• Mahananda

Perennial Nature

• These rivers are perennial, meaning they have water throughout the year. This is due to their source in the glaciers of the Himalayas.
• They are known for their fertile floodplains, where they deposit alluvium and frequently change their courses due to meandering.

Major Rivers Originating from the Himalayas

Ganga River

• Origin : The Ganga River originates from the Gaumukh glacier, located near the Gangotri Glacier in Uttarakhand, India. The Gangotri Glacier is situated at an elevation of 5,611 meters, north of the Kedarnath peak.
• Entry into Bihar : The river enters the state of Bihar near Chausa, in the Buxar district. Here, it forms a natural boundary between the Bhojpur and Saran districts.
• Length and Drainage Area : The total length of the Ganga River is approximately 2,500 kilometers. Out of this, 445 kilometers flow through the state of Bihar. In Bihar, the river has a drainage area of 15,165 square kilometers.
• Flooding and Navigation : The slope of the Ganga River is very gentle. During the monsoon season, this gentle slope causes the river water to spread over the embankments on both sides, creating flood-like conditions. The river is navigable throughout the state, making it a vital source for trade and transport.
• Tributaries : The Ganga has many tributaries that join it from both the north and south directions. From the north, the major tributaries include: Ghaghara, Gandak, Bagmati, Kamala Balan, Burhi Gandak, Kosi, and Mahananda rivers. From the south, the tributaries include: Karmanasa, Son, Punpun, Harohar, Kiul, Phalgu, and Chandan rivers.
• Bridges : The river has several bridges that connect North Bihar to South Bihar. Notable bridges include: Mahatma Gandhi Setu (road only), Rajendra Setu (road and rail), Jayprakash Setu (road and rail), Vikramshila Setu (road), Sri Krishna Setu (road and rail), Bakhtiyarpur-Tajpur Bridge (road), and Aguani Ghat Bridge (road).

Ghaghara/Saryu River

• Origin : The Ghaghara River originates from the Mapchachungo glacier in the Tibetan Plateau, near Lake Mansarovar in Nepal. It is also known as the Sharda River.
• Entry into Bihar : The river enters Bihar near Guthani in the Siwan district and joins the Ganga River at Revelganj in the Saran district. It joins the Ganga from the northwest direction in Chhapra.
• Cultural Significance : The Ghaghara River is highly sacred to Hindus and Buddhists. Its fast flow gives it the name Ghaghara or Ghaghar.
• Length and Flow in Bihar : The total length of the Ghaghara River is 1,080 kilometers, of which it flows for only 83 kilometers in Bihar. In the mountainous region, it is known as the Karnali River.
• Tributaries : The Ghaghara River is the second largest tributary of the Ganga, after the Yamuna. Important tributaries include: Choti Gandak, Khauna, Jharhi, Daha, Tel, and Sondi rivers.

Gandak River

• Origin : The Gandak River is an important waterway in North-Western Bihar. It originates from the Mustang glacier located in the Annapurna mountain range in Nepal. The glacier is situated near the villages of Manangmot and Kutang.
• Name in Nepal : In Nepal, the river is known as Kali. It flows through different streams in Nepal before entering Indian territory.
• Entry into India : The Gandak River enters India near the town of Triveni in Nepal. From there, it continues its journey through Indian states, including Bihar.

Gandak River

• The Gandak River originates in the Himalayas, flowing from the Nepal region into India. It begins its journey at a height of approximately 2,400 meters, making its way through the rugged terrain before entering the plains. The river is known for its significant length, spanning around 425 kilometers, with a substantial portion of its course (260 kilometers) flowing through the state of Bihar.
• As it meanders through the North Ganga plains, the Gandak River takes on a south-east direction. It serves as a natural boundary between the Indian states of Uttar Pradesh and Bihar for a portion of its course. The river enters Bihar from Valmikinagar, located near the Someshwar range, and continues its journey through several districts, including West Champaran, East Champaran, Muzaffarpur, Gopalganj, Siwan, Saran, and Vaishali in Bihar. Additionally, it flows through Gorakhpur and Deoria districts in Uttar Pradesh before finally joining the Ganga River downstream of Hajipur and Sonpur.
• The Gandak River is also known by various names, including Triveni, Narayani, and Kali Gandak. It plays a crucial role in the region's irrigation system, with the Triveni canal receiving water from this river. The river's importance is further highlighted by the Valmikinagar Barrage, which is situated on its banks.
• One of the notable features of the Gandak River is its propensity to change course, especially during the rainy season, leading to flood situations. While flood protection embankments have been established to mitigate flooding, abandoned river courses and accumulated rainwater during the monsoon create flood-like conditions. The river has also given rise to chaurs (marshy lands), lakes, and other water bodies along its banks.
• The total length of the Gandak River is 425 kilometers, with 260 kilometers flowing through Bihar. Its important tributaries include the Rohua, Manaur, Bhabsa, Gangri (or Gogri), Mahi, Dabra, and Avsa rivers.

Burhi Gandak

• The Burhi Gandak River, originating from the Someshwar hills, flows parallel to the Gandak River and is known for its meandering course. In its upper reaches, it is referred to as Sikrahana. The river passes through several districts in Bihar, including West Champaran, East Champaran, Muzaffarpur, Samastipur, Khagaria, and Begusarai.
• The Burhi Gandak follows the old course of the Gandak River, which was shifted westward from its present course. This is why the river is known as Burhi Gandak. Its course, from northwest to southeast, is similar to that of the Gandak River. The Burhi Gandak meets the Ganga River near Khagaria. With a length of 320 kilometers in Bihar, it is one of the fast-flowing rivers in the state.
• Important tributaries of the Burhi Gandak include Harha, Kapan, Mason, Banaganga, Pandai, Maniyari, Karha, Kohaura, Urai, Telabe, Prasad, and Tiur. This river system is characterized by a continuous chain of old and abandoned channels, such as Chatnaha, Kachnanala, Hardyanala, and Balnanala. Areas covered by the Burhi Gandak feature several chaurs, marshy lands, and water bodies.

Kosi River

• The Kosi River, originating from Mount Gosainthan in the northeastern part of Kathmandu, Nepal, is a significant waterway with a total length of 730 kilometers. However, only 260 kilometers of this river flows through the state of Bihar. The river has a vast catchment area of 86,900 square kilometers.
• Known for carrying heavy silt and sediments, the Kosi River frequently changes its course due to the massive load it deposits at its mouth. This characteristic has earned it the nickname "Sorrow of Bihar," as the northern Bihar plain is often affected by severe floods. Over the past 200 years, the Kosi River has shifted its course approximately 150 kilometers from east to west. In Nepal, it is called Saptakoshi, referring to its seven upper tributaries. Some of its major tributaries include Sun Kosi, Arun Kosi, Bagmati, Kamla Balan, Tamur Kosi, Fariani Dhar, Dhemana Dhar, and Bhuthi Balan.

Bagmati River

• The Bagmati River originates from the Mahabharat range in the Nepal Himalayas and enters the plains of Bihar from Rasulpur village in the Sitamarhi district. This river holds great significance in Nepal, where it is considered sacred. Notable temples, such as the Kathmanda and Pashupati temples, are located along its banks.
• Stretching over a total length of 394 kilometers, the Bagmati River is the second longest river in the state of Bihar. It flows through various districts, including Darbhanga, Sitamarhi, Sheohar, Muzaffarpur, Samastipur, and Khagaria, before joining the Kosi River in the Badlaghat district of Bihar.
• However, the Bagmati River is known for its unpredictable behavior, as it frequently changes its course, causing significant disruption in the districts it traverses. Its tributaries include Lalbakia, Lakhendei, Chankhala, Jamune, Sipri Dhar, Choti Bagmati, Kola, Bhurengi, and Adhwara.

Kamla Balan River

The Kamla Balan River originates from the Mahabharat range of hills in Nepal, near Sindhuliagarhi. This river, once known as "Jiwachh Kamla," is considered the second holiest river in Mithila, after the Ganga. In Mithila, it is affectionately referred to as "Kamla Mayi."

Rivers in Bihar

Rivers in Bihar can be classified into four categories:

• Rivers originating from Himalayas
• Rivers originating from the Plateau Region
• Rivers originating from South Ganga Plain
• Rivers flowing through Bihar

Rivers Originating from the Himalayas

There are three rivers which originate from the Himalayas. These rivers are:

• Kamala River
• Mahananda River
• Kosi River

Kamala River

Origin and Course

• The Kamala River begins its journey in the Madhubani district of Bihar, India.
• It enters Indian territory in the district of Madhubani, Bihar, about 3.5 km upstream of Jainagar town.
• The river flows through a catchment area of 4,488 sq km in Bihar.

Barrage and Length

• A barrage known as the Kamla Barrage has been constructed by the State Government near Jainagar to manage the river's flow.
• The total length of the Kamala River is 328 km, with 208 km in Nepal and 120 km in Bihar.

Distributaries and Tributaries

• After flowing approximately 120 km in Bihar, the Kamala River splits into various distributaries.
• Its main tributaries include the Dhauri, Soni, Balan, and Trisula rivers.

Confluence with Other Rivers

• One of its streams joins the Bagmati River at Badlaghat in Khagaria district.
• Another stream merges with the Kosi River at the boundary of Saharsa and Darbhanga districts.

Flooding and Damage

• The Kamala River is notorious for its severe flooding during the rainy season.
• When there is a breach in the embankment, it causes catastrophic floods, resulting in significant damage to life and property.=

Mahananda River

Origin and Course

• The Mahananda River originates from the Mahaldiran hill in the Darjeeling district of West Bengal, India.
• It is known for its unpredictable nature, often changing its course.
• This river is the easternmost river in the North Bihar plains, flowing southwest after emerging from the Himalayas.
• It forms part of the boundary between India (West Bengal) and Bangladesh.

Length and Entry into Bihar

• The total length of the Mahananda River is 376 km.
• It enters Bihar through the Kishanganj district and flows through the Kishanganj, Purnia, and Katihar districts of Bihar.

Confluence with Ganga and Tributaries

• The Mahananda River meets the Ganga River near Manihari in Katihar district before entering Bangladesh.
• Its important tributaries include the Mechi, Balason, Ratwa, Kanakai, Nagar, Dank, Pitanu, Changa, and Burhi Gangi rivers.

Rivers Originating from the Plateau Region/South Ganga Plain

These rivers originate from the Peninsular Plateau and flow northward to meet the Ganga River. Notable rivers from the Peninsular Plateau include:

Son River

Origin and Historical Significance

• The Son River originates from the Maikal range of the Amarkantak hills in Madhya Pradesh, near the source region of the Narmada River.
• In ancient times, it was known as ‘Sonbhadra’ and ‘Hiranyawah’.
• Over the last 2500 years, its course has shifted westward.
• The Son River is the longest southern tributary of the Ganga in Bihar.

Course through Bihar

• The river flows through the Rift valley, forming the boundary between the Palamu district of Jharkhand and the Rohtas, Aurangabad, Bhojpur, and Patna districts of Bihar.
• It enters Bihar through the Rohtas district and flows through Madhya Pradesh, Uttar Pradesh, and Jharkhand before reaching Bihar.
• The Son River finally meets the Ganga River near Danapur in Patna.

Geographical Features

• The Son River divides the Kaimur hills from the North Koel river valley, located to the south.
• Major cities along the Son River include Arrah, Dehri, and Sonbhadra.

Length and Tributaries

• The Son River is one of the largest rivers in India, with a length of 780 km, although only 202 km of its course is in Bihar.
• Its main tributaries include the Rihand, North Koel, Gopad, and Kanhar rivers.

Flood Management

• The Son River has a steep gradient, leading to quick runoff and ephemeral water regimes.
• Being wide and shallow, the river leaves disconnected pools of water for most of the year.
• The channel of the Son River is very wide, measuring about 5 km at Dehri on Sone, but the floodplain is narrow, ranging from 3 to 5 km in width.
• Flooding due to the Son River is managed with the Anicut at Dehri and the Indrapuri Barrage.

Punpun

• Origin and Course : The Punpun River starts from Chauraha Hill in the Palamu district of Jharkhand and flows into Bihar, where it traverses through districts such as Gaya, Aurangabad, Arwal, and Patna before joining the Ganga River near Fatuha in Patna. 
• Length and Characteristics : The river is approximately 200 km long. It is primarily rainfed and seasonal, resulting in minimal water flow during the dry season. However, during the monsoon, the Punpun River can cause significant flooding, particularly damaging areas east of Patna city. 
• Tributaries : Notable tributaries of the Punpun River include Dordha, Butane, Madar, Morhar, Ramrekha, Baraki, Yamuni, and Bilro. 
• Importance : The Punpun River is the second most important river in South Bihar, playing a crucial role in the region's ecology and hydrology.

Phalgu

• Origin : The Phalgu River originates from the northern part of the Chota Nagpur plateau in the form of several streams. The main stream, known as ‘Niranjana’ (or Lilajan), merges with the Mohana stream near Bodhgaya to form the Phalgu River. 
• Historical Significance : Bodhgaya, located on the banks of the Niranjana River, is where Gautama Buddha is believed to have attained enlightenment. 
• Cultural Importance : The Phalgu River is considered sacred not only in Bihar but across India. At its banks in Gaya, people perform ‘Pind Daan’ ceremonies to honor the souls of their ancestors. 
• Seasonal Behavior : During the monsoon season, the Phalgu River experiences heavy flooding. In other seasons, it diminishes into various streams and flows through sandy regions. 
• Division of Streams : The river divides into two streams near Barabar Hill in Jehanabad district and further splits into multiple streams like Dhohar, Dhanruji, Khuri, Lokain, etc.

Karmanasa

• Origin and Course : The Karmanasa River originates near Sarodag on the northern face of the Kaimur range of hills. It flows through Buxar district and meets the Ganga River, forming part of the Uttar Pradesh-Bihar border. 
• Tributaries : Key tributaries of the Karmanasa River include the Durgavati, Chandraprabha, Karunuti, Nadi, and Khajuri rivers. 
• Cultural Perception : The Karmanasa River is often regarded as cursed and unholy. Its catchment area includes the Kaimur hill region and the plains of Buxar district.

Sakri

• Origin : The Sakri River originates from the Hazaribag plateau in North Chota Nagpur. 
• Course through Bihar : The river enters Bihar near Govindpur in Nawada district and flows through Gaya, Nawada, Patna, and Munger districts. 
• Confluence with Ganga : The Sakri River meets the Ganga River along with the Kiul and Morhar rivers. 
• Irrigation Canal : An irrigation canal has been constructed from the Sakri River in Nawada district. The water from this canal is used for irrigation purposes in Gaya and Patna districts.

Ajay

• Origin : The Ajay River begins in Batpad, located in the Jamui district of Bihar. 
• Course : The river flows east and south, passing through Jharkhand and West Bengal before joining the Ganga River. 
• Length in Bihar : The river stretches for 202 km within the state of Bihar. 
• Alternate Names : The Ajay River is also known by other names such as ‘Ajyabati’ or ‘Ajmati’.

Chandan

• Formation : The Chandan River is formed by the confluence of five streams, which is why it is also called ‘Panchanan’. These streams come together to create a larger river near Giriak in the Nalanda district of Bihar. 
• Geographic Feature : The formation of the Chandan River is influenced by the barrier of the Rajgir hill, which causes the five streams to flow together as a single river.

Kiul

• Origin : The Kiul River originates from the Hazaribag plateau and enters Bihar through a narrow gorge near the Satpahari hill in the Jamui district. 
• Length in Bihar : The total length of the Kiul River within Bihar is 111 km. 
• Tributaries : Important tributaries of the Kiul River include Harohar, Anjan, Barnar, and Ulan. 
• Confluence with Ganga : The Kiul River meets the Ganges in Surajgarha village, located in the Lakhisarai district of Bihar.

Rivers of Bihar and their Place of Origin

Major Cities Along River Banks in Bihar

Waterfalls in Bihar

Bihar is endowed with stunning natural landscapes, and its diverse waterfalls greatly enhance the state's beauty. Waterfalls occur where water cascades from a significant height due to a steep slope in a river. These formations are typically found in areas with alternating layers of soft and hard rocks.
Here are some of the notable waterfalls in Bihar:

• Kakolat Waterfall: Situated in the southeastern part of Kakolat hills, approximately 35 km from Nawada near Govindpuri division, Kakolat Waterfall is the most renowned tourist destination in Bihar. With a total height of 47 m (160 ft) and a main drop of 24 m (80 ft), this waterfall features a natural pond at its base. It is located near the border of Bihar and Jharkhand and is often referred to as the "Niagara of Bihar." A fair is held here during Chaitsankranti. The waterfall is fed by seven streams originating from the Kodarma plateau.
• Karkat Waterfall: Nestled in the Kaimur district, Karkat Waterfall is a picturesque and captivating spot where water cascades down from a ravine. The area offers facilities for boating, swimming, and fishing, making it a popular destination for visitors. Additionally, the Kaimur Wildlife Sanctuary is located nearby.
• Telhar Waterfall: Located in the Kaimur district, Telhar Waterfall boasts a height of 262 ft as it plunges into a deep pool. Swimming in the pool is prohibited due to its significant depth and strong undercurrents.
• Tamasin Waterfall: This waterfall, situated on the Mahane river, descends from a height of 15 m (50 ft).
• Dhua Kund Waterfall: Located on the Kao river in Tarachandi near Sasaram (Rohtas), Dhua Kund Waterfall has a height of 30 m. It consists of a pair of waterfalls, and the water is harnessed for hydroelectricity generation with a capacity of 50-100 MW. This waterfall is part of the larger Manjhar Kund waterfall.
• Manjhar Kund Waterfall: Situated in the Kaimur hills near Sasaram (Rohtas), Manjhar Kund Waterfall is located on the Karmanasa river. A famous Raksha Bandhan fair takes place here annually.

Lakes in Bihar

The rivers of North Bihar, including the Ganga, Burhi Gandak, Kosi, and Mahananda, have created many natural lakes by altering their courses over time. These lakes are locally known as “Man,” “Tal,” or “Chaur.” They serve as fishing grounds, habitats for migratory birds, and sources of water for irrigation.
Some important oxbow lakes in Bihar are:

• Saraia Man (Betia)
• Soneburg Man (Harsidhi)
• Kharagpur Lake (Kharagpur)
• Siuri Man (Jogpatti)
• Moti Lake (Motihari)
• Pithra Man (Pithra)

Kanwar Lake:   

• Located in Manjhaul village, Begusarai district, Kanwar Lake is Asia’s largest freshwater oxbow lake, covering an area of 16 square kilometers.
• The lake was formed by the meandering of the Burhi Gandak River and is renowned for its diverse aquatic plants.
• During the winter months of November and December, migratory birds from Siberia visit the lake.
• Due to its rich aquatic flora, Kanwar Lake has been designated as a “Reserved Area.”
• The lake is home to around 110 bird species, leading to the establishment of a Bird Breeding Station in the area.
• However, the lake has experienced shrinkage due to sedimentation, eutrophication, and excessive plant growth, resulting in a decline in water levels.

Simri Lake:   

• Simri Lake is located 25 kilometers from Saharsa in the Simri division.
• The lake is actually a combination of several smaller lakes, including Jamunia, Sarria, Kumini, and Gobara lakes.
• Its shape resembles a horse-shoe, and it is situated with Kanwar Lake to the southwest and Kusheshwar Asthan Lake to the northwest.

Lakes in Bihar

Bihar is home to several beautiful lakes, each with its own unique features and significance. Here are some of the notable lakes in the state:

Gogabil Lake

• Location: Manihari sub-division, Katihar district.
• Also Known As: ‘Ghogha Chap’ or ‘Ghogha lake’.
• Area: Approximately 5 sq km.
• Water Sources: Receives water from monsoon rains and the Mahananda River.

Kusheshwar Sthan Lake

• Location: Kusheshwar Sthan sub-division, Darbhanga district.
• Area: About 100 sq km.
• Features: Known for its rich biodiversity and religious significance.
• Economic Importance: Major center for fisheries and trade.
• Conservation Status: Declared a bird sanctuary in Bihar in 1972.

Jagatpur Lake

• Location: Bhagalpur district.
• Area: Approximately 400 hectares, shrinking to 50 hectares during summer.
• Conservation Efforts: Preservation of various bird species with the help of local communities and the State Government.

Udaypur Lake

• Also Known As: Saraiya Man.
• Location: West Champaran district.
• Features: Popular tourist destination, attracting many migratory birds.

Muchilinda Lake

• Location: 3 km south of Mahabodhi Temple, near Mucharim village, Gaya district.
• Legend: Associated with the story of Muchalinda, the Snake King, who protected Lord Buddha during a storm while he meditated.

Anupam Lake

• Location: Kaimur Wildlife Sanctuary.
• Nearby Attractions: Karkat and Telhar waterfalls.
• Biodiversity: Rich in flora and fauna.

Wetlands in Bihar

Wetlands are areas covered by aquatic plants and swampy vegetation. According to the National Wetland Conservation Programme (NWCP), India has about 115 wetlands, out of which Bihar has 3 recognized wetlands:

• Kanwar or Kobar Wetland in Begusarai
• Kusheshwar Sthan Wetland in Darbhanga
• Baraila Wetland in Vaishali

Hot Springs in Bihar

A spring is a natural point where water flows out from the ground. This occurs when an aquifer is filled to capacity, causing the water to overflow onto the land surface. Bihar is home to several hot springs, where the water temperature ranges from 30°C to 70°C.
Rajgir is known for its many popular and historical hot springs, including:

• Saptdhara
• Surya Kund
• Makhdum Kund
• Nanak Kund
• Brahma Kund, which is famous for its extremely hot water reaching 150°C.