Following heavy rainfall, on August 17, 2016, Chandil dam, Jharkhand released huge amount of water in Subarnrekha River. As a result there was sudden surge of waters in Subarnrekah River causing worrisome situation in Jamshedpur town and in areas further downstream along the river in West Bengal and Odisha States.
Superficially the incident may appear a natural incident. But analysis of available information indicates that the flood impact could have possibly been reduced or avoided.
The incident:- On August 17 and 18, 2016, the ongoing South West Monsoon brought heavy rainfall in Jharkhand. The evenly distributed showers were measured as 80 mm across the State with Jamshedpur town located on the bank of Subarnrekha River recording maximum rainfall of 270 mm in 24 hours.
On August 17, 2016, Chandil dam located in Seraikela Khrasawan district about 30 km upstream Jamshedpur, opened up 13 out of 18 gates of the reservoir and discharged massive amount of water in Subarnrekha River. As a result there was water logging and flooding in Jamshedpur town with Subarnrekha River flowing 2.5 meters above the danger mark. Kharkai River joining the Subarnrekah from right side at Jamshedpur town was also reported as flowing 4.5 meters above the danger mark.
Google Earth Image of Flood affected areas in Jamshedpur
Due to incessant rainfall, Subarnrekha and Kharkai Rivers were already in spate and the release of water from Chandil dam during the same period further flooded Subarnrekha river dangerously. Subsequently the water flooded several households in Shastri Nagar, Baghbera, Kadam, Mango localities in Jamshedpur town forcing the administration to set up 26 relief camps to provide relief to affected people.
On August 18, the flood surge reached Chormundi village under Baliabera police station in West Bengal which lies at the border of Jharkhand and West Bengal. The location is about 130 and 50 km downstream of Chandil dam and Galudi Barrage (both in Jharkhand territory) respectively. There 28 people carrying out mining in the previously dry riverbed were caught unaware of approaching flood water. In no time, they were encircled by rising currents and their lives were put under threat by imminent flood. In order to save the people, the administration had to carry out emergency rescue operation and thus could manage to avoid a disaster.
Swollen Subarnrekha in Odisha River (Source media report)
Further, on August 19, 2016 the flood wave reached lower parts of Subarnrekha River banks in Odisha State. The State Government has sounded flood alert in Jaleswar, Basta, Baliapal, Bhograi areas in Balasore districts and Rasagobindpur block in Mayurbhanj districts. The two districts have been asked to deploy disaster relief forces in their respective districts at strategic locations to take up search and rescue operations.
As per the latest news reports, the water level of the Subarnrekha River has crossed the danger mark of 10.36 metre at Rajghat in Balasore district on August 19, 2016. According sources, the release of excess water from Galudih barrage in Jharkhand is likely to affect lives of 4 lakh people in more than 250 villages.
Could this flood impact have been avoided or reduced?
- As per Central Water Commission inflow forecasting records of August 19, 2016, water level in Chandil dam is 10 meters below its Full Reservoir level of 192 m, which means it could have stored more water or released the water in regulated manner thus not causing the flash flood situation downstream areas, as can be seen from the screenshot taken from CWC Flood Forecasting site at 12 noon on Aug 19, 2016.
- As there were continuous rains happening in Subarnrekha catchment areas resulting in high flows in Subarnrekha and other contributing streams, Chandil dam authority should have avoided releasing water that would add to the flood flurry in the downstream area.
- Authorities in Odisha also reported that about 2.85 lakh to 3 lakh cusec of water was released from Galudi barrage which is located about 60 km downstream of Chandil dam. As barrages does not have big storage capacity, the substantial part of the release from the barrage is likely to be from the Chandil dam.
- Administration in Odisha also complained about absence of communication from Jharkhand officials about the sudden discharge.
- The emergency evacuation of 28 miners from Chormundi village also indicates that there must have been lack of communication by Chandil dam authorities.
Considering all the facts, it is clear that the Chandil Dam Authorities could have avoided releasing so much water in already flooded Subernrekha river thus avoiding or reducing flood impacts in downstream areas.
Due to wrong water release decision of Chandil Dam Authority thousands of local people in Jamshepur (Jharkhand), Chormundi (West Bengal) and Mayurbhaj and Balasore districts (Odisha) have been put in difficult situation. Lack of communication from the dam authorities and from Jharkhand to neighboring downstream states and people further added to avoidable disaster situation.
It is not for the first time that wrong operation of a dams have created avoidable flood impacts in the downstream area. The least one can expect is that the Jharkhand, W Bengal, Odisha and CWC & Union Ministry of Water resources will investigate this incident and put out a report in public domain and learn lessons so that such incidents are avoided in future.
Bhim Sing Rawat (firstname.lastname@example.org) SANDRP
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