Large Dams, barrages, reservoirs and canals

Dams have often been regarded as man’s response to nature’s vagaries, to mitigate flood and drought by containing water and releasing it as per demand and supply. Lately, dams are seen more as hydropower generators with flood mitigation, irrigation and drinking water supply only being additional benefits. This can be because of the increased acceptance that dams and canals, as awe inspiring as their structures might be, fail to deliver water to more than half of their commands. However, data and experience tell us that even the hydropower generation is also falling way below the promised numbers.

History and extent of dams in India

India’s first dam is the Kallanai built on the Cauvery river by King Karikalan of the Chola dynasty around 2,000 years ago. The dam, which is still functional and irrigates millions of acres, spans 329 m in length and 20 m in width. However, it was only post-independence that India’s love for big dams became more intense with the commissioning of a slew of projects including the Hirakud (1957), Gandhisagar (1960), Bhakra-Nangal (1963) and Nagarjuna Sagar (1967). Since then, the country has been continuously working on reining in its rivers for want of power, irrigation and domestic and industrial water supply needs. Almost half of the large dams in the country were built in the two decades of 1970-90. Maharashtra has the maximum number of large dams in the country (1845) followed by Madhya Pradesh (905) and Gujarat (666).

Map of major dams in India

A multi-purpose dam project includes one or more dams, infrastructure for generation of hydropower, infrastructure for housing of workers and for offices, a distribution network of canals and pipe systems, and access roads. All these have their individual and cumulative impacts on the river and the surrounding environment. Here also lies an opportunity to minimise the 'collateral damage' caused by dam projects by minimising the footprint of these adjuncts.

Dams as power generators

Hydropower is often billed as a renewable, economic and non-polluting source of energy and hence there is an increased emphasis on building dams especially in the hydrologically-rich but geologically-fragile Himalayan states. An assessment study put the hydroelectric power potential of the country at about 84,000 MW with maximum schemes envisaged on Brahmaputra basin (226) followed by Indus basin (190) and Ganga basin (142).

Possibility of revenue generation through sale of power units to other states and private players remains the main draw for state governments to invite project developers. However, reports suggest that poor financial conditions of discoms make it a poor proposition. Average generation per MW of hydro capacity in India in 2014-15 was over 20 per cent less than that in 1993-94.

Dams and canals for irrigation

Canal system of irrigation had been prevalent in India for centuries but it was the Ganga Canal that laid the foundation for large scale diversion of water to farms.

Number of dams in various statesThough the work was undertaken under the leadership of British Colonel Proby Cautley, it was the traditional acumen of local villagers that made the vast network possible. The canal was commissioned in 1855 irrigating around 5,000 villages. Today, the system irrigates nearly 9,000 km² of agricultural land in 10 districts of Uttar Pradesh and Uttarakhand.

The start of the Green Revolution in the mid 1960s put the spotlight on canal irrigation as the new hybrid crop varieties bred on heavy dose of chemical fertilizers and pesticides demanded assured irrigation. However, the increased investment and network expansion dealt little benefits. The World Commission on Dams in its year 2000 report found that the contribution of large dams to increased food grains production in India was less than 10 percent.

Loss in seepage, huge demand-supply gap, diversions under political pressures and comparatively easier and local availability of groundwater through pervasive use of borewells are the reasons for decline in efficiency trend.

Between 1996-97 and 2002-03, the area under canal irrigation declined by 2.4 million ha (13.8 per cent), the area under tank irrigation fell by 1.4 million ha (42.4 per cent), and the area irrigated by all other sources declined by 1 million ha (28 per cent). The only irrigation source that increased its share was groundwater wells, by 2.8 million ha (more than 9 per cent).

A study of 210 major and medium irrigation projects by SANDRP used the data supplied by the Ministry of Agriculture to show that after investing Rs 130,000 crore, these delivered 2.4 million ha less irrigation during 1990-1 to 2006-7. This means, the governments have to invest twice as fast in canal irrigation projects every year just to keep their command areas from shrinking

The study said that around Rs 1,00,000 crore was wasted in the name of improving irrigation. Feasibility studies were fudged in the case of most of the projects with huge investments, over-optimistic predictions were made and very little money was earmarked for basic maintenance such as desiltation. In some cases, political interests ensured that water was diverted to unviable areas at the cost of needier regions.

Dams and flood control

The efficiency of dams to withhold floods has always been put to question. Critics have also termed dams as harbinger of floods claiming that the essential scientific assessment for consistent release of water to avoid build up is rarely done.

Absence of a standard operating procedure for releasing water from the dam gates was evident in 2014 when 24 students picnicking in a river were swept away due to sudden release of water from Larji dam in Himachal Pradesh

Similarly, area downstream of Hirakud dam in Odisha has witnessed 14 floods in recent past with nine caused by sudden release of water from the dam. A major reason is that the dam has not changed its flood control strategy for 23 years while the rainfall pattern has undergone major changes in local areas. Lack of a coordination mechanism between neighbouring states about water flow also leads to emergency situations like one in 2011 when sudden release of water flow from upstream dams in Chhattisgarh led to breaching of danger mark in Hirakud.

In Gujarat, sudden release of large quantities of water from Ukai dam led to the biggest flood of 34 years in Tapi river submerging over 80 per cent of Surat, killing 150 persons and stranding over 20 lakh. Similar examples have been reported from other states.

Problem with 'training rivers'

Dams cause a disruption in the flow of a river by transforming it into a series of pools separated by dry stretches. The environmental impacts can be felt on the landscape, water resources, forest cover, and biodiversity. The Himalayas are almost equally distributed between zones 4 and 5. While a series of dams are being constructed in a seismically vulnerable and ecologically fragile zone, not only is optimisation of the planned development not considered, but the cumulative effects of the dams also are not considered. On a local level, blasting increases the possibility of landslides, and causes air and noise pollution. Quarrying on hill slopes and in the riverbed causes pollution and destabilisation of the slopes.

The large scale construction that is an inescapable part of hydropower development leads to deforestation. It has been observed that construction leads to the inadvertent loss of much more forest than has been accounted for. The presence of a dam on a river also impacts the ecosystem by bringing about a drastic change in the species composition. Invasive species tend to appear and flourish while suppressing endemic species and even causing some to become extinct. 

An affidavit filed by Ministry of Environment and Forest in the Supreme Court admitted the role of hydropower projects in Uttrakhand disaster in 2013. It said that “the maximum damage sites in the disaster affected areas (were) located either upstream or immediately downstream” from hydropower projects.

According to a paper by the United Nations Environment Programme, dams and their associated reservoirs permanently impact on freshwater biodiversity by several processes. Climate change has also been linked with dams. Studies show that large dams cause anoxic decomposition which leads to the formation of methane gas. This ‘greenhouse gas’ produced by dams may contribute to global warming to an appreciable extent. According to a study, dams contribute about 24 per cent of the total methane emissions in the world. Of these emissions, India contributes slightly under 28 per cent.

Submergence and displacement

Though the benefits of a dam are often exaggerated, the estimates related to land submergence and possible displacement of people are invariably kept low to paint a positive picture.

From Hirakud to Bhakra Nangal to Tehri and many more, scores of affected families were not rehabilitated at all. Those rehabilitated also complained about lack of livelihood opportunities and poor living conditions. Narmada Valley project, around which a big people's movement was built, remains the most controversial irrigation and hydropower plan. Envisaging around 30 irrigation and hydroelectric multipurpose dams, the project's environmental and social costs vis-a-vis the benefits have been cause of much debate and litigations. Sardar Sarovar dam, the largest structure on Narmada river, is believed to have displaced over 3 lakh families and is expected to displace additional 2.5 lakh families if its height is further increased by recently-approved 17 metre.

The World Commission on Dams in its report says: “While dams have delivered many benefits and made a significant contribution to human development, in too many cases the price paid to secure those benefits, especially in social and environmental terms, has been too high and, more importantly, could have been avoided.”

Political issues around dams

Shortage of water is increasingly being felt resulting in conflicts across the world. For the same reason India is facing disputes both within and outside its boundaries. While Punjab, Haryana and Rajasthan are fighting over water sharing from Bhakra Nangal, Kerala and Tamil Nadu went to court on diversion of water from Mullaperiyar dam.

On the other hand, Pakistan claimed that design of Baglihar project in Jammu and Kashmir violated the Indus Water Treaty whereas India is wary of China's plan to tame Brahmaputra waters through a series of dams. Similar are the concerns of Bangladesh which lies further downstream over India's attempt to build dams.

Way forward

It is evident that instead of focusing on building new dams, we need to attend to underperformance of existing projects. Decentralised solar, wind energy and small hydroelectricity projects with local communities as their managers as well as consumers can offer sustainable alternatives to big dams. This will not only mitigate ecological and social impacts of power generation but also reduce cost of power generation and distribution.

For irrigation purposes, revival of traditional community-managed networks like kuhls of Himachal Pradesh, phad irrigation of Maharashtra and recharging of underground aquifers through rainwater

The World Commission on Dams lists seven steps as a remedy to issues arising from dams. These include gaining wide public acceptance, exploration of alternatives to dams, optimal usage of existing structures, protection and restoration of ecosystems at river basin level, recognising entitlements of the affected people, compliance with applicable regulations and regional co-operation on trans-boundary rivers.

A few of the western countries, having realised the futility of large dams, are trying to help rivers reclaim their territory. Dams that no longer serve a useful purpose, are too expensive to maintain safely, or have harmful impacts are facing the axe especially in United States where the rate of decommissioning of large dams has overtaken the rate of construction since 1998.

The provision of adequate environmental flow releases from dams is an important means of achieving a compromise between overt exploitation of our rivers and a non-practical cessation of all use. Attempts have been made towards the assessment of these flows for the Ganga, and an ongoing project aims to achieve implementation of these flows in the Ramganga. The successful process of e-flows in India may indicate that it is going to be mainstreamed into water resource management policy.

 

Featured Articles
December 4, 2022 What is the status of inland fisheries in India? Read these situational analysis reports to know about inland fisheries, the life of the fisherfolk, governance and tenure in inland fisheries and threats to the sustainability of inland fisheries.
Fishing in an irrigation canal in Kerala (Image Source: Martin Pilkinton via Wikimedia Commons)
November 23, 2022 Inspite of the realisation that minimum flows are essential for rivers to maintain their health and biodiversity, water released from various dams in India continues to disregard minimum environmental flow requirements.
Cauvery river at Hogenakal, Karnataka. (Source: IWP Flickr Photos via Claire Arni and Oriole Henri)
March 25, 2022 Dammed and bound, will the beautiful river Teesta survive India's insatiable demand for electricity?
Heaven on earth: A view of the Teesta from the coronation bridge (Image Source: Paramanu Sarkar via Wikimedia Commons)
November 21, 2021 Upstream hydrological modifications altered the basin hydrology, says study
Kathiya Gaon, Tehri, Uttaranchal (Image: India Water Portal)
October 25, 2021 Will it be possible to achieve tradeoffs between meeting water needs of people and retaining river waters to sustain the rare and beautiful, but endangered Indus River Dolphin in the Beas river?
Beas river at Kullu, Himachal Pradesh (Image Source: Wikimedia Commons)
July 26, 2021 Do dams worsen floods? These videos by Jeevitnadi Living River Foundation highlight the role of dams in controlling floods and the emerging challenges to flood management in India.
Hirakud, India's oldest dam (Image source: India Water Portal on Flickr)
The Mullaperiyar conflict : Meeting to understand issues and explore a common ground, 4 Aug 2009, New Delhi
Posted on 02 Aug, 2009 07:50 PM

Image and Content Courtesy: Forum for Policy Dialogue on Water Conflicts in India Guest Post by: K J Joy, Forum for Policy Dialogue on Water Conflicts in India The Forum for Policy Dialogue on Water Conflicts in India (Forum to be brief) is happy to invite you to the “The Mullaperiyar conflict: Meeting to understand issues and explore a common ground” to be held on 4th August 2009 between 4 to 8 pm at Constitutional Club, New Delhi. The Forum for Policy Dialogue on Water Conflicts in India is a collaborative effort of many organisations and individuals in the country working on water and especially on water conflicts. The Forum’s work is guided by a Steering Committee and Advisory Committee consisting of some of the important names in the water sector in the country. The Forum began its work in 2004-05 and in the initial couple of years the main focus was to understand different types of conflicts in the country and took up extensive documentation of conflicts across the country. The cases have now been published as a book by Routledge, “Water Conflicts in India: A Million Revolts in the Making”. Presently the Forum is engaged more in activities that can help in resolving conflicts or making them more tractable through scientific studies and dialogue amongst the conflicting parties. The Forum has also taken the initiative to set up two groups of experts to work on two important issues related to water conflicts in the country, namely, 1) water allocations for livelihood needs and ecosystem needs; and 2) the legal-institutional framework for conflict resolution. The Forum aims to take up these issues for wider discussion and debate so that certain degree of social consensus can be built around these two critical issues. Some of the Forum partners are also engaged in active conflict resolution in their respective states. The Forum does believe that with scientific inputs and a spirit of cooperation and dialogue amongst the conflicting parties most of the conflicts around water can be resolved. It is in this spirit that the Forum has taken the initiative to organize this meeting on the Mullaperiyar conflict.

Dr. GD Agarwal's fast to resume
A press release on Dr. GD Agarwal's resuming his fast Posted on 09 Jul, 2009 01:57 AM

 

  1. The state government of Uttarakhand promised immediate suspension of all works on the two projects Bhairoghati and Pala-Maneri in its letter of 19th June, 2008 and expressed its full commitment for conservation of River Bhagirathi in its natural form ‘from Gangotri to Uttarakashi’. However construction work on the projects (particularly on Pala Maneri project) leading to destroy Gangaji is going on in full swing. The above makes all assurances to us and to Maa Gangaji look as mere jokes.
  2. The Government of India committed immediate stoppage of all work on its project Loharinag-Pala in its letter on 19th February, 2009. But the construction work on the site has gone on un-stopped and on an accelerated speed. This again is an act of cruel deceipt.
Dams, Rivers and People (April - May 09): Poor track record of the NDA & UPA in the water sector
Dams, Rivers and People (April - May 09): Poor track record of the NDA & UPA in the water sector Posted on 08 Jun, 2009 04:00 PM

Forwarded to the Portal by: Himanshu Thakkar, SANDRP

The latest edition of the Dams, Rivers and People Newsletter is out !

Wake up call on reservoir siltation nationwide
Storage capacities of the reservoirs have been dropping and the loss is alarming; what's worse, little is being to done to stop the wastage Posted on 28 May, 2009 09:30 AM

"Wake up call on reservoir siltation nationwide", is a note by Himanshu Thakkar & Swarup Bhattacharyya, written in October 2006, on how storage capacities of the reservoirs have been dropping at an alarming rate, and how little is being to done to stop the wastage.

Concurrent monitoring of the world's largest drinking water pipeline project - A study of Narmada based project in Gujarat
The report provides comprehensive review of Narmada project and scope to improve the performance of the project by reorienting the state policy for drinking water Posted on 27 May, 2009 02:56 PM

This report presents the findings of a study done by Pravah on the concurrent monitoring of the world's largest drinking water pipeline project, the Narmada project, which is supposed to cover 9633 villages an 131 towns of Saurashtra, Kutch and parts of North Gujarat.

Water issues faced in Hyderabad metropolitan city - A presentation by Hyderabad municipal water supply and sewerage board
The presentation deals with the present capacity, supply and supply situation, allocation of Singoor water and the Krishna water supply scheme Posted on 12 May, 2009 12:36 PM

This presentation by M G Gopal of the Hyderabad Metropolitan Water Supply and Sewerage Board deals with the water issues faced in the city. The issues presented include – (a) Inter-sectoral allocation (b) Meeting the demand (c) Maintaining quality standards (d) Reducing unaccounted for water (e) Recycle and reuse (f) Promoting rainwater and conservation (g) Implementation of CDS and (f) Is ‘privatisation’, a solution or a disaster?

Improving flood management and water quality: a case study of Chicago, United States of America
The presentation provides an overview of the O’Hare CUP reservoir in Chicago, in particular its capacity, construction details, service area and the average annual flood savings ($2.3 million) Posted on 11 May, 2009 02:23 PM

These presentations deal with a case study of the work done in Chicago City in the United States of America to improve flood management and water quality. In order to save construction costs, the reservoir side walls are composed of geomembrane liner over compacted clay.

The Sambalpur declaration on Odisha rivers : Let the river flow
The Sambalpur declaration on Odisha rivers : Let the river flow Posted on 23 Apr, 2009 12:04 PM

Water Initiatives Orissa(WIO) and the Indian River Network (IRN) organsied the Odisha River Conference during 18 - 20 April 2009 at Sambalpur, Odisha. Attended by about 75 participants which included activists, environmentalists, journalists, academicians, researchers and civil society representatives from across the country, the Conference has just concluded with a "Sambalpur Declaration" that calls for saving the rivers from the current fate of high rate of degradation and giving communities their traditional rights over the rivers, among other strong resolutions.

Hydroelectric power projects & climate change: A case study of Ravi basin in Himachal Pradesh
The Role of Hydroelectric Power Projects in the Climate Change: A Case study of Ravi basin in Himachal Pradesh Posted on 09 Apr, 2009 11:34 AM

The following is a paper by Dr. Mohinder Slariya based on data collected during his Ph.D work. The work contains data sourced from the India Water Portal, and aims to illustrate local area climate changes with the development of hydroelectric projects. The abstract of the paper has been quoted below, with the full paper available as a download!

Abstract

Dams have had serious impacts on the lives, livelihoods, cultures and spiritual existence of indigenous, tribal and illiterate people, moreover on the physical environmental conditions and on the biodiversity of the area concerned. The dam related developmental activities in Ravi catchment area have been threatening the biodiversity in the whole catchment. There are more than 50 rivulets in the Ravi catchment and on which more than 70 power projects have been planned by the government by putting biodiversity at the stake. Developmental activities have unintentionally produce weather and climate modifications on a larger scale and threaten the existing biodiversity. Such developmental activities have been started day back in 1980s in Ravi basin with the installation of Baira Suil Power Project and today it has covered all most all Ravi basin starting from interstate broader of Jammu & Kashmir, Punjab and Himachal Pradesh and engulfed the green cover of the area. Because of this extinction the catchments area is experiencing drastic climatic changes, because of 100 km reservoirs of Shahpur Kandi (125MW), Thein Dam (600MW), Chamera-I (540MW) and Chamera-II (300 MW) and tunnelization of Ravi in 19.38 kms with a dia of 7 to 9 meters and 102 meters high surge shafts with 15.5 meters dia and underground power houses of Chamera-I & II and dry Ravi in almost all its natural route (27 kilometers in Chamera I & II). In this dry region there is a tremendous increase in the temperature and there is no timely and usual rain in the basin after the installation of power projects.

Request for photographs on dams for publishing in FlyLite magazine
Posted on 19 Mar, 2009 10:29 AM

Send to the Portal by Divya Mishra Assistant Editor FlyteLite ========== I handle a magazine called FlyLite (which is the in-flight magazine for JetLite) and for our April issue, we're carrying a story on the dams and bridges of India. We are currently looking for images for the following structures: 1. Gandhi Setu, Patna 2. The Grand Anicut Dam, Tamil Nadu 3. Idukki Dam, Kerala 4. Hirakud Dam, Orissa 5. Krishna Raja Sagara Dam, Karnataka

×