With increasing stock of old, unsafe, unwanted dams, India needs decommissioning policy

By Himanshu Thakkar* 
India’s dams and decommissioning as per the Parliamentary Committee for Ministry of Jal Shakti, in its 20th report dated March 2023, the committee had asked the Department of Water Resources, River Development & Ganga Rejuvenation under the Ministry of Jal Shakti about the mechanism put in place in India to assess the viable lifespan and performance of dams and projects, which has a direct bearing upon the consideration for dam decommissioning.
The Department had replied: “There is no mechanism to assess the viable lifespan and performance of dams… However, no information/recommendation from the dam owners has been submitted for de-commissioning of any of their dams.”
The committee noted that according to 2019 edition of National Register of Large Dams compiled by Central Water Commission (CWC), there are 234 dams older than 100 years, some of them over 300 years old.
On a query as to how many dams which are more than 100 years old have been decommissioned in India, the Department submitted: “As per the information available in CWC (Central Water Commission), no such dam has been decommissioned in India.”
It may be added here that dams need huge expenditure to maintain them, but we in India are very poor at maintenance. That makes our dams even more unsafe and prime candidates for decommissioning. It also means we need even more urgently to have a policy and program for decommissioning of dams.
The Parliamentary Committee has recommended: “In view of the foregoing, the Committee recommend the Department to take suitable measures for evolving a viable mechanism to assess the lives and operations of the dams and also persuade the States to decommission those dams which have outlived their lifespan and may pose a severe threat to life and infrastructure in case of any failure. The Committee would like to be apprised of the steps taken by the Department in this regard within three months from presentation of this Report.”
It is not in public domain if the Ministry or the department in question has taken any action in this regard.
India must conduct a cost-benefit analysis of its ageing dams, and conduct timely safety reviews in order to ensure their operational and ecological safety, as well as the safety of those who inhabit the areas downstream, authors of a 2021 global study of dams by United National University said. The Report shows that while dam decommissioning is a relatively recent phenomenon, it is gaining pace in the USA and Europe.
The report says: “A few case studies of ageing and decommissioned large dams illustrate the complexity and length of the process that is often necessary to orchestrate the dam removal safely. Even removing a small dam requires years (often decades), continuous expert and public involvement, and lengthy regulatory reviews. With the mass ageing of dams well underway, it is important to develop a framework of protocols that will guide and accelerate the process of dam removal.”

Dams needing decommissioning

Some good candidate dams for decommissioning in India Mullaperiyar dam on Periyar river in Kerala, now over 130 years old, is a dam whose decommissioning has been advocated by the Kerala government, but Tamil Nadu government that operates the dam and gets all the benefits and no risk in case of dam disaster, does not agree. The government of Kerala carried out hydrological review studies between 2006 and 2011 that concluded that the Mullaperiyar Dam is unsafe for passing the estimated probable maximum flood. 

The proposal from Kerala government to the Union Ministry of Environment and Forests for stage I environment clearance for the new Mullaperiyar dam in 2015 also included a section on dismantling of the old dam after construction of the proposed new dam. The proposal did not get clearance considering the inter state aspects.
Similarly, Bihar Chief Minister Nitish Kumar has publicly, repeatedly advocated for decommissioning of Farakka dam on Ganga river, built in the downstream W Bengal. His reasons: the sedimentation, drainage congestion, reduced carrying capacity of rivers and increases flood vulnerability in Bihar. 

The Dumbur (also known as Gumti) dam in Tripura is also a good candidate for decommissioning, as advocated by a number of researches and groups in Tripura. In fact, the power generation from the upgraded 15 MW installed capacity at the Dumbur Dam in Tripura is so low that even the World Bank strategy paper for the North East (dated June 28, 2006) recommended exploration of decommissioning of the dam.
The Maheshwar dam on Narmada River in Madhya Pradesh is another good candidate, since it is providing no benefits, but has many impacts and risks.
India has no policy or program for decommissioning of aged, unsafe and economically loss making dams. Ministry of Environment and Forests (MoEF) constituted Western Ghats Ecology Expert Panel (chaired by Prof Madhav Gadgil) Report has suggested dam decommissioning as one of the important recommendations. No steps have been taken in this regard by the MoEF subsequent to the report.

Bihar CM wants Farakka dam decommissioned, as Ganga's reduced carrying capacity has increased flood vulnerability

However, nature has been decommissioning some of the dams. For example, in early Oct 2023, the Glacial Lake Outburst Flood on Teesta River in Sikkim washed away the 60 m high dam of the 1200 MW Teesta 3 dam. In Feb 2021, similar flood had destroyed the dam of the Tapovan Vishnugad Dam and Rishiganga hydropower project in Chamoli district of Uttarakhand. Similarly a large number of dams had faced damage and destruction in Uttarakhand in June 2013 floods. 

The Tajewala barrage on Yamuna river in Haryana was washed away in floods after commissioning of its replacement Hathnikund barrage. In Oct 2023, the Medigadda barrage on Godavari river on Maharashtra-Telangana border faced damage as six of its pillars sank. 

The Dam Safety Team sent by the Centre has recommended full rehabilitation of the barrage. We may face increasing frequency of such incidents, at great cost to society and economy if we do not decommission unsafe, unwanted dams.

Dams are even more risky in changing climate

The intensifying rainfall patterns in changing climate are making the dams more risky and hence even stronger candidates for decommissioning. The intensifying rainfall pattern is increasing the probable maximum precipitation and probable maximum flood that any dam will experience. 

But the dams and their spillway capacity have not been designed for such higher floods, leading to need for retrofitting to increase the spillway capacity of the dams at huge extra costs, as it being done now in case of Hirakud dam on Mahanadi river in Odisa at huge cost. In fact Hirakud dam, one of the earliest to be built in post independent India, an earthen dam, is another dam whose safety needs to be urgently assessed as also that of the Damodar River Dams.
In fact, an assessment of changed design flood for all large dams is required, keeping in mind the changed rainfall pattern, reduced storage capacity of the dams keeping in mind silt accumulation in its live storage capacity and reduced carrying capacity of the rivers downstream and the same needs to be compared with the spillway capacity to assess the safety of the dam. 

Decisions then needs to be made about the feasibility and viability of increasing spillway capacity to match the new reality and where this is not possible, also assess the need for decommissioning of the dams.
Dams are not natural solutions. The climate scientists are telling us to look for nature based developmental path and solutions. The world and India are facing multiple interconnected crises, from climate change, to injustice, to the loss of rivers, nature and biodiversity and increasing disasters. Rivers flow through these challenges, and river restoration can be a powerful nature based solution. Restored, free flowing rivers are also required for cultural needs, livelihoods and life in general.
India thus urgently needs a policy, plan and program for dams decommissioning dams, considering the increasing stock of old, unsafe and unwanted dams and also increasing risks that we face from such dams. The changing climate is making this need even more urgent.
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*Source: South Asia Network on Dams, Rivers and People