The Kosi river basin: Reducing flood risk

Extending across Tibet (China), Nepal and India the Kosi River represents the largest river basin in Nepal. The Kosi River is a powerful river system with a history of shifting directions and causing havoc in Nepal and India. Such is the potential damage that can be caused by the Kosi, it has become known as the “Sorrow of Bihar.” Thousands of families in Nepal and millions in India continue to live in fear that at any moment, the Kosi River might burst its banks and create widespread suffering.

Communities along the Kosi flood plains do not have to think too far back to remember the power and impact a flood can have. In 2008, the Kosi River broke out of its embankment near Paschim Kusaha Village in Sunsari district of Nepal. The ensuing flood affected 70,000 families and displaced 7,000 families in Nepal, while affecting another 3.5 million people in India. The breach of the embankments and ensuing flood were not caused by the monsoon rains.  In fact, the monsoon was below average during that time, so the potential impacts could have been far worse.

The 2008 Kosi River flood is a stark reminder of Nepal’s vulnerability to floods and the need to address this vulnerability through disaster risk reduction and preparedness rather than a focus on relief.

In 2011, the Government of Nepal officially launched the Nepal Risk Reduction Consortium (NRRC). The NRRC is a unique institutional arrangement that brings together humanitarian, development and financial partners to reduce Nepal’s vulnerability to natural disasters. Based on the National Strategy for Disaster Risk Management (NSDRM) and additional consultations, the NRRC established 5 flagship priorities for disaster risk reduction.

Flagship 3 of the NRRC is focused on Flood Risk Management in the Kosi River Basin. Coordinated by the World Bank and the Ministry of Irrigation, Flagship 3 aims to enhance flood forecasting and early warning systems of the Kosi River while reducing vulnerability of at-risk communities.

The Kosi River has a demonstrated history of changing river paths, making it a complicated and dynamic river to address flood risks. In October 2011, the World Bank undertook a rapid assessment of the 15 Kilometre section of the eastern Kosi embankment maintained by the Government of Nepal (include link to study). This assessment found critical infrastructure needing immediate repair and strengthening works.

The immediate needs were well understood by all relevant stakeholders and, in February 2012, the Government of Nepal and Government of India agreed that the two countries will work jointly towards strengthening a 15km stretch of the eastern Kosi embankment maintained by the Government of Nepal.

The Government of India has confirmed that the required immediate repairs have been completed and they are continuing to monitor the functionality of the embankments. The World Bank has been credited with its work in identifying the critical need of addressing the embankment strengthening and repair works.

While the progress in reducing the risk of floods from the Kosi River has been positive, more work is required. The World Bank and Global Facility for Disaster Risk Reduction (GFDRR) has just released a detailed report on the long-term interventions required for reducing flood risk in the Kosi River. This report will serve as a guideline for the additional work that needs to be carried out in the Kosi River Basin.