Himalayan Catastrophe that Engulfed North Bihar

The recent Kosi megaflood, caused by a breach in the Kosi embankment in Nepal on August 18, 2008 and a sudden change in the course of the Kosi River, was one of the most significant and damaging flood events ever to hit Bihar. The Kosi disaster also ranks as one of the greatest disasters in India. This preliminary note briefly discusses some of the available details of the megaflood, the past great floods on the river, the special hydro-geomorphic characteristics of the basin, and the probable reasons for the failure of structural measures designed to mitigate the flooding problems on this Himalayan river with unique behavioural characteristics.