In the planning for dams as well as their management, sometimes a conflict develops between safety aspects and the maximization of irrigation and/or hydro- electricity benefits. Whenever such a conflict exists, as a general principle, the decision should also always be on the basis of according much higher importance to safety aspects. Safety should be considered the decisive factor in all such situations, on the basis of the non-negotiable principle that ultimately human life is most precious, much more precious than anything else.
Of course this is not to say that irrigation or/and hydro-electricity are not important. Certainly these are very important. Livelihoods of many people are also related to these. However if a conflicting situation develops with regard to choosing between safety and various benefits, and if the safety threat is well-established, then there should be absolutely no doubt that safety aspects should be considered most important and decisive.
This is not at all a question of comparing the interests of people of various regions or states, or of comparing who benefits and who loses. The simple principle is that safety of people is most important, saving human lives is most precious. The matter ends here, or at least should end here.
Presently this issue is being discussed in India in the context of Mullaperiyar dam controversy. This controversy should be settled on the same principle of safety being the most decisive factor. Of course if while deciding on this basis, livelihood of some people is adversely affected, then alternative means of helping them should also get the due attention and resources. Where irrigation is reduced, for example, small-scale water harvesting can be encouraged to a much greater extent, with adequate additional resources being allocated for this.
In the Himalayan region, in Uttarakhand, Himachal Pradesh and elsewhere also, many people are feeling threatened due to dams and in their case also the decisions should be taken by prioritizing safety above other concerns.
At a time when the task of preparing a project report for the Barahshretra high dam project on Kosi river as an India-Nepal joint initiative has picked up, it is necessary to go back to about six decades and recall why this project was considered and abandoned then.
On September 22, 1954 Anugraha Narayan Singh, the then Finance Minister of Bihar informed the Vidhan Sabha, “For about 2 to 3 years it has been investigated whether a 700 feet high dam will be constructed on Kosi river and a lot of money has been spent on this. …But later when it was considered that if the 700 feet dam collapses then the entire Bihar and Bengal will be submerged and ruined, this idea was given up.”
Around the same time N.V. Gadgil told the Lok Sabha that when tests were conducted the entire area was revealed to be affected by seismicity. Then, he said, alternatives to this project has to be considered keeping in view the possibility of collapse of dam.
In 1934 a highly destructive 8.3 intensity earthquake had devastated parts of Bihar and Nepal and the possibility of another such quake had led the authorities and their experts to abandon this project.
Now that the Barahshretra Kosi project has been revived, it will be useful to recall the entire debate of those times particularly regarding the safety aspects. Dinesh Mishra, engineer, social activist and author who has written the most detailed history of various Kosi river projects has stated that he is extremely apprehensive about how the folly of existing faulty flood protection approach can be worsened further by unsafe, ill-advised projects like the Barahshretra high dam. At present the worst affected are those people, numbering about a million, who are caught between the embankments and the Kosi river. Instead of helping them, the authorities have inflicted more misery on them in the course of implementing the recent Kosi Mahasetu project. If in future these people have to live with the threat of sudden massive discharge of dam water, as has been the case of many high dam projects, their tragedy can be imagined. The silt content of Kosi water is extremely high, and danger of very rapid silting of reservoir will be very high here.
But such factors have never received adequate attention in decisions regarding dam construction in India. In the case of the extremely controversial Tehri Dam Project, it was in fact an officially constituted experts committee (river valley projects appraisal committee of the Union Ministry of Environment) which had stated explicitly that the risks of this project were unacceptably high and the project should be given up. What was the action on this recommendation – the project work was speeded up further!
During the last 65 years nearly 50 dams have collapsed in India. The case for more adequate safety monitoring has become stronger because of the growing threat of Reservoir Induced Seismicity (RIS). Recent evidence from China, particularly the Three Gorges Project, indicates that this threat can be much bigger than what was earlier believed. The seismicity here has increased by 30 times after the impounding of water and over 3000 small quakes have been reported, leading to the eviction of about 300,000 people affected by resulting landslides.
One of the biggest tragedies caused by dams in India, the Machu dam disaster of August 1979 killed several hundred people and destroyed Morvi town as well as several villages. According to the Consumer Education and Research Centre, Ahemdabad, Machu dam was designed on the basis of outdated empirical formula. Although in the course of the project study conducted before constructing this dam the Central Water and Power Commission had thrice asked the state government to check on a more scientific formula for the construction of the dam, the government went ahead with the construction of dam without having carried out this exercise. It was only at a very late stage when a major share of the dam had already been constructed that this exercise was conducted, and then somehow the findings were tailored to fit in with the almost already constructed dam.
In addition the following other cases of dam failure in India may be mentioned :-
l Kaddam Dam – following heavy rainfall in the catchment, this composite dam failed in August, 1959. This failure was attributed to inadequate spillway capacity.
l Chickahole dam (1972) – This mansonry structure failed in December 1972 due to tension caused at dam base on account of water level rising to top of the dam.
l Dantwada (1973) – A breach occurred along the reservoir periphery in September 1973.
l Aran (1978) – This case of earth dam failure has been described as a classic case of foundation failure generated by seepage.
l Jaswant Sagar dam – This dam in Rajasthan breached in July 2007 despite the fact that it was supposed to be monitored under the World Bank funded ‘Dams Safety Assurance and Rehabilitation Project”.
l Gararda – This dam in Rajasthan collapsed in August 2010. The enquiry committee report highlighted criminal negligence and corruption leading to substandard work.
Another fact which may be pointed out is that the rehabilitation of the victims of dam failure often leaves much to be desired. In 1961 the earthen dams at Panshet and Khadakwasala dam (Maharashtra), breached, bringing death and destruction to the villagers. About 200 lives were lost, and 14,000 families were rendered homeless. Despite the rehabilitation efforts made by the government the life of these victims remained uncertain for a long time.
Thus heavy damage and large scale distress has been caused by dam failures in the past and as most suitable sites have been exhausted and future dams are being built at more difficult sites, such as in the Himalayas, the need for caution can hardly be overemphasized. An adequate machinery to assess hazards of projects before they are constructed and to monitor their safety after they start functioning is a must. Adequate financial provision for this should be made.
There have been some cases when we have come quite close to major dam distress. Fortunately these have been averted. But the near failure should be cause enough for a thorough review of the safety aspects. Such a review, it appears, is not made in such cases. According to statements made by senior officials themselves, the giant Bhakra dam has come close to failure twice at the time of torrential rainfall and heavy inflow of water. Similarly the Farakka project came under a cloud as in 1989 the irrigation Minister of W. Bengal himself sounded warnings about the threat to the safety of this structure.
It was due to lack of adequate consciousness about dam safety that the Mullaperiyar dam issue was converted into an inter-state issue between Kerala and Tamil Nadu while it should have been treated first and foremost as a dam safety issue. The first step should have been to ensure the safety of people affected by a threatened dam. Now after the Wayanad landslide disaster the safety concerns have increased, and so after collecting all the relevant and updated data and information, the Kerala government can again approach the Tamil Nadu government, the Government of India and the Supreme Court of India for resolving the issue on the basis of top priority being given to saving human lives.
Bharat Dogra is Honorary Convener, Campaign to Save Earth Now. His recent books include Planet in Peril, Protecting Earth for Children, Man over Machine and A Day in 2071.