Floods in Bihar

When heavy rains occur in the mountains of central and eastern Nepal the water flows into the major drainages of the Narayani, Bagmati, and Koshi rivers.

A recent fact-finding report on the Kosi floods of 2008 – prepared by a civilian organization, the Fact Finding Mission on the Kosi, composed of various experts such as Sudhirendar Sharma, Dinesh Kumar Mishra, and Gopal Krishna – highlighted the fact that although India has built over 3000 km of embankments in Bihar over the last few decades, the propensity for flooding has increased by 2.5 times during the same time period, not to mention that embankments failed during each major flooding event.

In the case of the Kosi, it found that because of siltation the river bed had risen several feet in relation to the adjoining land.

The high and low lands separated by embankments have created a situation where the lowlands have become permanently waterlogged.

Upon completion of the system of embankments, 3,465 km had been constructed and were administered by the Water Resources Department (WRD).

The river, which flowed in a South Easterly course between Rajmahal and Farakka during early decades of this century, has now formed a concentration of meander loops to accommodate the additional discharge due to the barrage.

Due to the obstruction caused by the Barrage, each year nearly 640 million tonnes of silt are accumulated in the riverbed.