86 dams in Tamil Nadu, including Mettur and Vaigai, to come under the scanner of independent panels of experts

Mettur, Bhavanisagar, Amaravathy and Vaigai are among 86 dams and reservoirs in the State which will come under the scrutiny of independent panels of experts in the next six months. 

The experts will examine 19 dams from the angles of safety, design, seismology, hydro mechanics, geology, hydrology and instrumentation.  Former chairmen of the Central Water Commission (CWC)  J. Chandrashekhar Iyer and A.K. Bajaj;  former chiefs of the Krishna River Management Board Yoginder Kumar Sharma and Shailesh Kumar Srivastava; former Chief Engineer (CE) in the Tamil Nadu Water Resources Department R. Selvam; former  CE in the CWC T.K. Sivarajan; former deputy director general of the Geological Survey of India R. Srinivasan and BIS [Bureau of Indian Standards] Chair Professor, National Institute of Technology in Tiruchi K Muthukumaran are among the experts.  The superintending engineer concerned will function as member-secretary of each such panel. 

Approving the formation of the panels, the Tamil Nadu government, in an order issued early this week, included Cholavaram, a balancing reservoir between the Satyamurti Sagar  in Poondi and the Red Hills tank, all of which are meant for water supply to Chennai.  The selection of all the 85 dams and reservoirs has been done on the basis of the water bodies having been identified as specified dams under the National Dam Safety Act, 2021. These dams and reservoirs are under the jurisdiction of the Water Resources Department (WRD). In addition, 38 dams, being maintained by the Tamil Nadu Green Energy Corporation (TNGEC) in the State, have been included in the list and they include Pykara and Kadamparai.  The power utility has formed similar independent panels for dam safety evaluation.  

The National Dam Safety Authority (NDSA) has put in place such a system for four inter-State dams –  Mullaperiyar, Parambikulam, Thunakadavu and Peruvaripallam – which come under its jurisdiction. In the run-up to the enactment of the Act, Tamil Nadu had opposed the move to bring the dams under the NDSA’s control, as it had argued that the dams “are  owned, operated and maintained” by it, a claim contested by Kerala in view of the dams having been located in its territory. 

As per the law, the first comprehensive dam safety assessment for each dam should be carried out on or before December 30, 2026, when the deadline stipulated by the Act lapses.  It is to facilitate the study that the government has cleared the creation of the panels.

Of the 123 dams in the State listed under the law,  five dams are aged at least 100 years; 59 – between 50 years and 99 years; 40 – between 25 years and 49 years, and 19 – less than 25 years.