Important Rivers Causing Floods in Bihar

• Kosi: The Sorrow of Bihar, because its floods occur regularly with heavy sediment deposition and change of course within a few decades.
• Gandak: An important Himalayan river with a catchment that rises in, and partly covers, Nepal; major source of flooding in north-western Bihar.
• Burhi Gandak: It is flows through the northern side of Bihar and causes flooding.
• Bagamti: Starts in Nepal and is a cause of flooding in north Bihar.
• Kamla-Balan: This river is a Himalayan river, which add on flood in northern Bihar.
• Mahananda: It passes through north-eastern Bihar and is related to flood vulnerability in that region.
• Ghaghra: A tributary on the way to Ganga from east side, it is a Himalayan river, which experiences high waters, contributing floods in plains.
• Ganga: The main river of Bihar; Flood due to high water level and overflowing tributaries.

Ganga — Tributaries of Ganga (Left-Bank and Right-Bank)

Left-bank tributaries

• Ghaghra
• Gandak
• Burhi Gandak
• Kosi
• Mahananda

Right-bank tributaries

• Son
• Punpun
• Karmanasa
• Kiul
• Chandan

Important Tributaries of Flood-Prone Rivers

Prelims Practice Questions

Q.What is the popular name of states river known as ` Sorrow of Bihar ‘?

A. Gandak

B. Kosi

C. Punpun

D. Ghaghra

Answer: B. Kosi

Explanation: Kosi river is Sorrow of Bihar due to frequent flooding, huge amount of sediment load and shifting its course.

Q. Which of the following are left bank tributaries of Ganga passing form Bihar?

A. Son and Punpun

B. Gandak and Kosi

C. Kiul and Chandan

D. Karmanasa and Son

Answer: B. Gandak and Kosi

The Gandak and Kosi join Ganga from the left or northern bank when viewed downstream.

 Q. Which of the following river has its basin extending into Nepal?

A. Punpun

B. Kosi

C. Son

D. Kiul

Answer: B. Kosi

Kosi has a Himalayan catchment, extending into Nepal. Downstream flows can be augmented due to heavy monsoon rainfall in its upper catchment.