The breach of the Kosi embankment in Nepal in August 2008 marked the failure of conventional ways of controlling floods. After discussing the physical characteristics of the Kosi River and the Kosi barrage project, this paper suggests that the high sediment content of the Kosi River implies a major risk to the proposed Kosi high dam and its ability to control floods in 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.