“Gandak River”

•  River System: Gandak is a major Himalayan river and a left-bank tributary of the Ganga.

• Names: In Nepal, it is known as Gandaki/Narayani; in India, it is called Gandak. The upper river is associated with Kali Gandaki.
• Origin: The Gandaki system originates in the Himalayan/Tibetan Plateau region and drains central Nepal before entering India.
• Major Tributaries: Kali Gandaki, Trishuli, Budhi Gandaki, Marsyangdi, Seti, Madi and Daraudi constitute the major tributaries of the Gandaki system.
• Course in India: It enters India near Valmikinagar in West Champaran, Bihar, flows through northern Bihar and joins the Ganga near Hajipur/Sonpur.
• Gandak Barrage: The Gandak Barrage at Valmikinagar is an important India–Nepal water-management and irrigation project. The bilateral Gandak Agreement was signed in 1959 for construction of the barrage in Nepal.
• Flood Significance: Heavy rainfall in the Nepalese catchment can rapidly increase Gandak discharge, making it important for flood management in Bihar and eastern Uttar Pradesh.
• Ecological Importance: The river system is associated with the Valmiki Tiger Reserve region and important riverine ecosystems.
• Map Point: Gandak lies broadly between the Kosi system to the east and the Karnali–Ghaghara system to the west.

UPSC Prelims Question

Q. Consider the following statements regarding the Gandak River:

1. It is a left-bank tributary of the Ganga.
2. It is known as Narayani in Nepal.
3. The Gandak Barrage is associated with an India–Nepal water agreement.
4. It joins the Ganga near Patna/Hajipur.

Which of the statements given above are correct?

Answer: 1, 2, 3 and 4

Explanation: Gandak/Narayani is a transboundary Himalayan river, enters India near Valmikinagar and joins the Ganga near Hajipur/Sonpur. The 1959 Gandak Agreement provides the bilateral framework associated with the Gandak Barrage project.