2008 Kosi Flood
| Geolocation: | 26° 29' 45.3547", 86° 53' 35.2191" |
|---|---|
| Total Population | 3.33,300,000 millionmillion |
| Total Area | 14001,400 km² 540.54 mi² km2 |
| Climate Descriptors | Humid mid-latitude (Köppen C-type), Monsoon |
| Predominent Land Use Descriptors | agricultural- cropland and pasture |
| Important Uses of Water | Agriculture or Irrigation, Domestic/Urban Supply, Fisheries - wild, Livestock |
| Water Features: | Kosi River |
| Riparians: | India |
| Water Projects: | Kosi Barrage and Embankment System (The Kosi Project) |
| Agreements: | Agreement Between the Government of India and the Government of Nepal on the Kosi Project (1954), Amended Agreement Between His Majesty’s Government of Nepal and the Government of India Concerning the Kosi Project (1966) |
Contents
Summary
Natural, Historic, Economic, Regional, and Political Framework
The Kosi River (also referred to as the Koshi, or Sapta Koshi) is a major tributary of the Ganges that flows through Tibet,
Nepal and India. The Kosi system was described as an inland delta built by the large sediment flux by Gole and Chitale (1966). The dynamic nature of the Kosi is most easily seen in its westward movement within the Indian State of Bihar – a shift of over 120 km in the past 250 years.
Following disastrous floods in the Kosi basin in 1954, India and Nepal began a National Flood Control Policy. The program included 3 major stages – the construction of a barrage in Nepal to harness the western migration of the river and allow for the development of hydropower and irrigation projects, the construction of eastern and western embankments above and below the barrage to reduce flood event frequency, and an additional dam (as yet unbuilt) at Barakshetra, Nepal to provide additional flood prevention and hydropower.
Because of the great instability and sedimentation rates of the Kosi, the embankment system requires regular monitoring and maintenance. Changes in river geomorphology due to scouring and deposition of transported sediment can affect the stability of embankment sections and spurs. The breach in 2008 occurred when two spurs collapsed over a 24-hour period, leading to a breach in the embankment between them. The failure occurred due to scouring of the spurs, not because of extreme precipitation. The flow on August 18, 2008 was less than 20% of the recorded maximum flow. [1]
Issues and Stakeholders
Flood Prevention: Coordination/trust/communication between local/community, regional/state, national levels required to inspect, monitor, report, and repair transboundary project infrastructure.
NSPD: Governance, Values and Norms
Stakeholder Types: Federated state/territorial/provincial government, Sovereign state/national/federal government, Local Government, Non-legislative governmental agency, Community or organized citizens
Flood Response: Limited communication (early warning) and limited response capacity lead to disastrous results.
NSPD: Governance, Assets, Values and Norms
Stakeholder Types: Federated state/territorial/provincial government, Sovereign state/national/federal government, Local Government, Non-legislative governmental agency, Development/humanitarian interest, Community or organized citizens
Due to different tabulation methods by local government, NGO, and other reports, it is difficult to provide a precise value on the extent of the damage in both India and Nepal. However, the lives lost due to flooding (in the hundreds) are small compared those lost to illness in the aftermath (thousands). The flood destroyed standing crops (primarily rice, other grains, jute and sugarcane) and washed away the nutrient rich topsoil and deposited tons of sand, rendering land largely infertile. Roads, water sources and other personal and public infrastructure was destroyed by floodwaters.
This breach occurred over a 24 hour period of time. Had there been an effective early warning service or system in place, there would have been time for households to prepare or evacuate and for government and NGOs to begin staging for recovery efforts [1]
Analysis, Synthesis, and Insight
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Key Questions
Transboundary Water Issues: What kinds of water treaties or agreements between countries can provide sufficient structure and stability to ensure enforceability but also be flexible and adaptable given future uncertainties?
The breach site for the 2008 flood was in Nepal, and most of the flood impacts there occurred in the Sunsari districts, with about 60,000 people affected. However, a few kilometers downstream, in India, about 3.3 million people were affected in Bihar (Supaul, Saharsa, Madhepura, Araria and Purnia districts). Neither the 1954 or 1966 Kosi Project Agreements addressed the issue of economic responsibility for disasters due to project failure. While flooding had been common along the river prior to the agreements, no mechanism was included to address future flood concerns, disaster response capacity, or economic outcomes or responsibility in case of infrastructure failure.
Additionally, the shifting path of the Kosi and powerful scouring and sedimentation patterns along the river have proved to be a greater challenge than originally envisioned by the engineers who developed the project. The flood control structures have altered the flood regime, but without constant monitoring and maintenance, they are likely to fail again. While the project altered the original flood risks in the region, it has had unintended outcomes that include high maintenance costs and increased risk of catastrophic flood due to structural failures. The Project Agreements address the need to provide maintenance for the structures, but did not identify or address specific needs or provide a mechanism for strong enforcement of the responsibilities of either party.
External Links
- NRRC Flagship 3: Flood Management in the Kosi River Basin (Youtube Video) — Flagship 3 of the Nepal Risk Reduction Consortium (NRRC) is coordinated by the World Bank and the Ministry of Irrigation. This video provides more background on the Kosi River, images of the embankments and river, and information about the NRRC program. The english narration is only in the left channel. The video is approximately 6 minutes long.
- ^ 1.0 1.1 UNESCO Koshi Flood: Rapid Hazard And Risk Assessment (Post-Flood Return Analysis) (2009) Report available online: http://un.org.np/sites/default/files/report/tid_188/2009-06-01-UNCESC-Rapid-Hazard-and-Risk-Assessment.pdf
