The Kosi

The Kosi is also an antecedent river. It is often referred to as the 'Sorrow of Bihar’. Arun is its main stream which originates from the northern slopes of Mt. Everest in Tibet (China). After piercing the Greater Himalayas in Nepal, it is joined by the Sun-Kosi from the west and the Tamur-Kosi from the east. Both these rivers run for a fairly long distance parallel to, and north of, the Mahabharata Range and join River Arun to form the Sapt-KosL This river cuts across the Mahabharata Range and the Shiwalik Hills, and emerges into the Bihar Plains near Chatra in Saharsa District. In Bihar Plains, it splits into numerous capricious channels. It is known that about 200 years ago, the Kosi used to flow by the side of Purnea town, but now by its westward migration it is about 160 km to the west of Purnea. In July, 2008, the Kosi River shifted its course towards east by more than 100 km. The devastating flood was declared as a national calamity. The Kosi river joins the Ganga River 30 km west of Manihari. It has however, been tamed since 1962 by the construction of embankments on its two banks.