Secure the dams

Centre should not leave the job to states

The government’s initiative to conduct the first ever “break analysis” of all the 5,247 major dams in the country to assess their vulnerability and to formulate emergency action plans for them is a much needed move. What is surprising is why nobody thought about taking such a critical measure earlier given that the viability of many of the dams has been known to be gravely endangered due to ageing, silting and worsening ecological conditions. Going by official reckoning, about 80 per cent of the large dams are older than 25 years. The majority of them have surpassed their designed lifespan of 50 to 60 years. Worse still, 196 dams are more than 100 years old and need to be suitably strengthened or replaced with new ones. Since a large proportion of the aged dams are made of mud, clay or other locally available materials, they run a greater risk of cracking or collapsing compared to concrete dams of recent vintage. Mercifully, the rate of dam failures in India is not too dissimilar from the global trends. Yet the damage-causing potential of such mishaps is far greater here than elsewhere because of the existence of habitations closer to the dams, a high density of population and the lack of flood-proofing treatment of the basins concerned. 

At least 36 major dam failures have already occurred. The most notable ones among them include the Tigra dam in Madhya Pradesh (1917), Machchu-II in Gujarat (1979), Ashti in Maharashtra (which, in fact, caved in twice in 1833 and 1933), Panchat in Jharkhand (1961), Khadakwasala in Maharashtra (1961), Nanak Sagar in Uttarakhand (1967) and Chikkahole in Karnataka (1972). Among the recent disasters, the most noteworthy was the breach of the Kosi embankment near the Indo-Nepal border in 2008 which affected over 2.3 million people in Bihar. The danger of dam bursts has accentuated because of the increased frequency of climate change-induced extreme weather events and the consequential sudden heavy water inflows into reservoirs. Besides, a large number of reservoirs are located in highly earthquake-prone zones. Hopefully, the mooted dam safety audit would not be confined to the appraisal of the failure probability alone but would also go into a host of other issues such as structural deficiencies, malfunctioning of operational and monitoring arrangements and the flaws in the design of spillways. 

This exercise would also be futile if the recommended remedial action is not taken expeditiously. Leaving this task to states would be dicey even though they are the legal custodians of these dams. No doubt, many states are doing the routine maintenance and repair work quite effectively, but they may hesitate to make heavy investments on structural improvements in the dams. The Centre may, therefore, need to come to their assistance. It is a pity that the Dam Safety Bill to enact a central law for this purpose has been on the anvil since 2010 without making much headway. The finalisation and passage of this crucial bill, which has already been discussed with states and whetted by the NITI Aayog, should not be delayed any further. Otherwise, the purpose of scrutinising the safety of dams will not be fully served.