➤ It originates from Mount Gosainthan which is located to the North-East of Kathmandu, capital of Nepal.
➤ The total length of this river is 730 km. Out of this, it flows for only 260 km in Bihar.
➤ It brings heavy silt and sediments with it after emerging from Himalayas and deposits this heavy load on its mouth, due to which it changes its course frequently. This river has very peculiar nature of shifting its course. Because of this nature of Kosi, the plain region of Northern Bihar is mostly affected by frequent floods. Thus, it is known as ‘Sorrow of Bihar’.
➤ It is known as Saptakoshi in Nepal for its seven upper tributaries. Its important tributaries are Sun Kosi, Arun Kosi, Bagmati, Kamla Balan, Tamur Kosi, Fariani Dhar, Dhemana Dhar, Bhuthi Balan, etc. The river Kosi is formed by the confluence of three streams namely the Sun Kosi, the Arun Kosi and Tamur Kosi all taking their origin in the Himalayan region of Nepal and Tibet.
