Kosi River

1. It is a transboundary river which flows through China, Nepal and India. 
2. It drains the northern slopes of the Himalayas in Tibet and the southern slopes in Nepal.
3. The Kosi River is also known as Saptakoshi for its seven upper tributaries which includes:
   1. Tamur river
   2. Arun river
   3. Sun Kosi
   4. The tributaries of Sun Kosi include Dudh Koshi, Likhu Khola, Tamakoshi River, Bhote Koshi, and Indravati.
   5. Kamalā, Bāgmati (Kareh) are the major tributaries of Kosi River in India, besides minor tributaries such as Bhutahi Balān
4. Kosi is the 3rd largest tributary of the Ganges by water discharge after Ghaghra and Yamuna.
5. In the past, the river has shifted its course for more than 133 km (83 mi) from east to west during the last 200 years.
6. The Kosi River is known as the "Sorrow of Bihar" as the annual floods affect about 21,000 km² of fertile agricultural lands thereby disturbing the rural economy.