The Kosi embankments were built in late 1950s to retain the Kosi River which is a transboundary river between Nepal and India and is one of the largest tributaries of the Ganges.It was conceptutalised during the first Bihar Government of CM Shri babu and his deputy Anugraha Babu. According to the agreement with Nepal, the responsibility of maintaining these embankments was vested in the Government of Bihar.
History of breaches
1963 : The inaugural breach had to be faced on the western embankment in Nepal in 1963 near the village Dalwa. Binodanand Jha of the Congress Party was the chief minister and the responsibility of the breach was passed on to rats and foxes that dig holes in the body of the embankments through which water seeps and the embankment fails. The other reason for the failure was given that because of the bad road conditions, the boulders could not be brought to the site.
1968 : Then came the breach of 1968 at five places in Jamalpur (Darbhanga). This was caused due to the highest flow of 913,000 cu ft/s (25,900 m3/s) ever recorded in the river but an enquiry held by the Chief Engineer – Floods of CWC, P N Kumra revealed that the failure was once again caused by the rats and foxes. The state was under the President’s Rule then.
1971 : The Bhatania Approach :Bundh that was constructed in 1968-69, collapsed between 10th to 19th kilometer below Bhimnagar in 1971 and many villages were washed away but eastern embankment had not breached.
1980 : The next incident occurred in 1980 near Bahuarawa on the eastern embankment in Salkhua block of Saharsa district near 121st kilometer below Bhimnagar. The river eroded the embankment in about 2 kilometers reach but just after eroding, it receded very fast and did not spill onto the countryside. The state was ruled by Dr Jagannath Mishra of Congress Party then.
1984 : In 1984, a tragedy as bad as Jamalpur struck the eastern embankment near Hempur village in the Navhatta block of Saharsa district, 75 kilometers below the Bhimnagar barrage. It had uprooted half a million people and had engulfed 96 villages in 7 blocks of Saharsa and Supaul districts. People could go back to their villages only after the Holi festival of 1985 when the breach got plugged. The breach was repaired at a cost of Rs. 8.2cr. Bindeshwari Dubey of Congress Party was the Chief Minister.
1991 : In 1991, there was a breach in the western embankment near Joginia in Nepal that led to a political crisis in Bihar and the Water Resources Minister of the state had to resign his post. This resignation was never accepted by Lalu Prasad Yadav who was the Chief Minister of the state then. This was a repeat performance of Bahuarawa breach where the river had receded after eroding the embankment.
2008: see 2008 Bihar flood