Major Rivers of Bihar
The Ganges (Ganga)
The Ganges, known as Ganga in Hindi, is the most sacred river in India and flows through the heart of Bihar. It enters the state near Buxar and flows eastward, covering a distance of about 445 km within Bihar before entering West Bengal.
The river holds immense religious significance for Hindus, with important pilgrimage sites like Patna and Munger located along its banks. The Ganges basin in Bihar is one of the most fertile regions in India, supporting intensive agriculture and dense population.
Key Facts:
- Length in Bihar: Approximately 445 km
- Major cities on its banks: Patna, Munger, Bhagalpur, Buxar
- Major tributaries in Bihar: Gandak, Kosi, Son, Punpun
- Religious significance: Considered the most sacred river in Hinduism
The Kosi River
Known as the "Sorrow of Bihar," the Kosi River is infamous for its devastating floods that have shaped the region's history. Originating in the Himalayas of Nepal, it flows through northern Bihar before joining the Ganges near Kursela.
The Kosi is known for frequently changing its course, sometimes shifting by as much as 120 km in a single year. This unpredictable nature has led to numerous floods throughout history, affecting millions of people in the region.
Key Facts:
- Nickname: "Sorrow of Bihar" due to devastating floods
- Length: Approximately 729 km
- Major tributaries: Sun Kosi, Arun, Tamur
- Notable feature: Has shifted its course by over 120 km in the last 250 years
The Son River
The Son River is the largest southern tributary of the Ganges in Bihar. It originates in Madhya Pradesh and flows northeastward through Uttar Pradesh and Bihar before joining the Ganges near Patna.
Known for its pristine waters and scenic beauty, the Son River valley has been an important center of human settlement since prehistoric times. The river is also significant for irrigation and hydroelectric power generation.
Key Facts:
- Length: Approximately 784 km
- Major dam: Indrapuri Barrage
- Historical significance: Mentioned in ancient texts as Suvarnarekha
- Economic importance: Irrigation, fishing, and sand mining
The Gandak River
The Gandak River, also known as Narayani in Nepal, is a major tributary of the Ganges that flows through western Bihar. It originates in the high Himalayas of Nepal and enters India near Valmikinagar.
The Gandak basin is known for its fertile alluvial soil, making it one of the most productive agricultural regions in Bihar. The river is also home to the endangered Gangetic dolphin and supports a rich diversity of aquatic life.
Key Facts:
- Length: Approximately 630 km
- Major dam: Gandak Barrage at the Indo-Nepal border
- Wildlife: Home to the endangered Gangetic dolphin
- Cultural significance: Associated with the sage Valmiki, author of the Ramayana
The Bagmati River
The Bagmati River originates in the Kathmandu Valley of Nepal and flows southward into Bihar, joining the Ganges near Patna. In Bihar, it traverses districts like Sitamarhi and Muzaffarpur before merging with the Ganges. The river’s banks around Patna host several ghats and temples, making it both culturally and religiously significant.
Though seasonal fluctuations can be large—swelling during monsoons and shrinking in dry months—the Bagmati is crucial for irrigation and groundwater recharge in northern Bihar. It also supports local fisheries and is lined by numerous small settlements that depend on its water.
Key Facts:
- Total length: Approximately 621 km (across Nepal and Bihar)
- Basin area in Bihar: Covers parts of Sitamarhi, Muzaffarpur & Patna districts
- Significance: Pilgrimage sites along its banks; supports agriculture and irrigation
- Challenges: Prone to flooding in monsoon; faces pollution and encroachment issues near urban areas
The Mahananda River
The Mahananda River rises from the Mahaldiram Hill at Darjeeling in West Bengal, then flows through Siliguri and enters Kishanganj district of Bihar. It continues southward, forming part of the Bihar–West Bengal border, before joining the Ganges near Manihari in Katihar district. The Mahananda’s catchment supports both hilly and alluvial plains.
In Bihar, the river is vital for irrigation and inland fisheries. Towns like Kishanganj and Katihar rely on its waters. During monsoons, its tributaries swell, often causing localized flooding, but in winters the flow reduces significantly, exposing sandbars that are used by locals for agriculture.
Key Facts:
- Total length: Approximately 360 km (entire course)
- Basin area: Covers parts of Kishanganj, Purnia & Katihar districts in Bihar
- Significance: Supports irrigation, fisheries, and links hill-fed water to the Ganges
- Challenges: Seasonal flooding in monsoon; bank erosion and sedimentation
