Keywords: Kosi, Floods, Bihar, Embankment, Disaster. Kosi or the Sapta-Koshi (named after its seven tributaries: The Sun Kosi, Indravati, Dudh Kosi, Tama Kosi, Likhu Khola, Arun & Bhote Kosi) is a transboundary Himalayan River, which flows through Tibet & Nepal before entering India at Bhimnagar and finally meets the River Ganga at Kursela, Bihar. Along with having a length of about 720 Km and a total catchment area of about 71,500 km, Kosi holds important historical significance too, it had been mentioned in ancient epics like Mahabharata as “Kausiki”, in Valmiki Ramayana, and also in Markandeya Purana as a primal force, due to its violent nature. However, in recent times, it has earned a new name “The Sorrow of Bihar,” primarily because of the devastating annual floods that its constant course changes bring to the region. It is said to have changed its course by about 150 km westwards in the last 200 years alone. There have been several attempts to tame the river and control ...