Hydro power is another very crucial source for India and controversial too. Currently Hydro Power through large dams contribute 2nd largest share (40.7 GW) of total power generation and stands next only to thermal power. India is endowed with immense hydropower potential (148 GW), but it remains severely underutilized. It is very complex issue and Hydro power projects are often on radar of environmentalists as there are fears of damage to ecology, biodiversity and displacement of indigenous people. Every hydro power project, unlike other sources of energy, has very specific and different concerns which can’t be generalized. Hence an informed debate for every project is only possible when there is awareness about conditions persisting at the site.
Dams for the purpose of irrigation and drinking are being built from the times immemorial. Kallanai Dam (Grand Anicut) in Tamil Nadu was built in 2nd Century AD by Cholas and is still in use. Modern dam building activity started in latter part of 19th century and this time it was dominantly for power production purpose. First Hydroelectric dam in India was built in 1898 in Darjeeling, followed by Mettur dam in Tamil Nadu and Sivasamudram in Karnataka. As of now there are about 430 dams in India.
Some controversial dams are –
Sardar Sarovar Dam
It is largest Dam in India build on Narmada River having capacity to generate 1450 MW of power. It is multipurpose project is supposed to help drought prone Saurashtra and Kutch Region of Gujrat by providing supply of water for drinking and irrigation. Recently its height was allowed to be increased to 163 m by Narmada Control Authority. This is 2nd largest Concrete Gravity Dam by Volume in the world. This dam is alleged to displace around 2.5 lakh villagers and thousands of villages got submerged. Initially World Bank was to finance this project, but due to negative Environment Impact Assessment It withdrew its support. Now there are concerns for Rehabilitation of displaced people.
MullaPeriyar Dam
This dam is situated on Periyar River in Kerala, but is under control of Tamil Nadu government. It was built by British in 1890’s and was taken on 999 year lease from Travancore princely state. After independence its control remained with Tamil Nadu government. Normally a dam has productive safe life of 40-50 years, but at that time British projected its life of 2000 years. Since then there have been recurrent repairs and renovations on the dam.
In1970’s there were minor earthquakes in surrounding areas which escalated conflict between Kerala and Tamil Nadu states. There are other dams on downstream Periyar river and Kerala government contended that if dam bursts the downstream dams wont able to hold water pressure released. On this Tamil Nadu agreed to lower water level to 120 feet from original 152 feet saying that it will repair the dam and then increase the level again.
Kerala government, on the other hand wanted to demolish this dam and construct a new dam. This was not agreed to by Tamil Nadu as it feared losing control of the dam. This dam is important for Tamil Nadu as it supplies substantial amount of electricity, irrigation and 5 districts of TN are dependent on this dam for drinking
Taking all views in consideration, Supreme Court this year gave ruling in favor of Tamil Nadu, upholding its right to raise water level to 142 feet.
Tehri Dam
It is 2.4 GW dam located in Garhwal district of Uttrakhand and is one the tallest dam in the world (260.5 meters). It is on Bhagirathi river operational since 2006. Project was conceived in 1970’s it resulted in submergence of Old Tehri town whose population was shifted to new town. As it is located on a highly seismic zone, there are apprehensions about any earthquake and its effect.
In Uttrakhand flashfloods of 2013 this damn is credited to have reduced the effect of disaster on downstream areas as it was far below its capacity and blocked enormous quantity of water from going down.
Subansiri Dam
This dam is under construction in Assam on Subansiri River, will have 2 GW capacities. It is run of the river project and expected to go operational by 2018. Again this project has been coping with protests of local people. This project is very crucial for power sufficiency of north east.
Bhakra Dam
This Dam is second tallest dam in India at 225 meters (next to Tehri) and it was 1st big dam of independent India. It was remarked by Pt. Nehru as ‘New temple of Resurgent India’. Its reservoir is called Gobind Sagar and is one of the largest reservoirs in India. This dam has installed capacity of 1325 MW and among cheapest source of energy at 20 paisa/ unit.
Kishenganga project
This is ‘run of the river’ dam for capacity of 330 MW on River Kishenganga in Kashmir. Through this project water will be diverted through tunnel to a power plant. This river enters Pakistan and is known as Neelum River. Under Indus Water Treaty India can’t use water of ‘western rivers’ I.e. Indus, Jhelum, Chenab beyond a certain extent. So Pakistan protested and took matter to ‘International court of arbitration’. Court allowed India to go ahead on condition that it maintains some minimum flow in river flowing to Pakistan. Quantum of water is yet to be decided. Interestingly, India’s stand was that diversion will only result in Inter- tributary transfer of water from Kishenganga to Jhelum River and water will ultimately go to Pakistan.
Dams exploit energy of running water to turn turbines and generate electricity. For this purpose flow of water needs to be adequate and in large number of cases it is monitored by building large reservoirs. There is advantage over other sources of power as supply of water (in turn, of power) can be regulated as per demand of power. In slack demand season (winters) water is stored in the reservoirs and is released as and when demand increases. These reservoirs also fulfill needs of irrigation, help in flood control and fulfill civil consumption. Such dams are called multipurpose dams. In fact, Green Revolution in India was backed by irrigation and at same time power problem was being addressed.
These reservoirs are created by building embankments & Concrete Dams which obstruct the flow of water and a lake is created. Alternatively, natural flow of river is not obstructed and a diversion canal is created which draws water from same river.
Water may be used directly for turning turbines which is called ‘Run of the River’ project. This is only possible in case of perennial rivers having consistent flow.
Gravity Dam
– These are built to hold back large amount of water and are as high as 200-300 ft. These are built using cement and concrete as compared to Mud and masonry stones used in embankments. Almost all large dams use this method. Here is pic of Bhakra Dam
Barrages: Barrage is obstruction created on flowing river to control water supply or to divert certain amount of water to canal. They consist of gates which extend from top to river bed and water flow is regulated by opening/closing these gates. In contrast, Dams have spillway gates at its top and water passes only when it reaches that height.
Important reservoirs of India In descending order as per their size –
Indira Sagar – In Madhya Pradesh on Narmada River
Nagarjuna Sagar – In Andhra Pradesh on Krishna River
Sardar Sarovar – In Gujrat on Narmada River
Gobind Sagar – In Himachal Pradesh on Sutlej River
Hirakud reservoir – In Orissa on Mahanadi River
Development vs Local people
Desirability of Dams is issue at center of debate involving social equity, Human Rights, Environment and Biodiversity.
There is no doubt that large dams displace large number of people. According to some estimates since independence various large dams has displaced around 3-4 crore people in India. There is resentment that these people never get there dues. Whole benefits of dams are cornered by Industries, Urban and rich people, while heavy price is paid by local people.
New Land Acquisition law (The Right to Fair Compensation and Transparency in Land Acquisition, Rehabilitation and Resettlement Act, 2013) states that land can be acquired for ‘public purpose’, and no consent is required in case of direct acquisition by government. Consent of 80% and 70% in case of acquisition for Private and PPP projects respectively.
Building of dams comes under public purpose and under old law there was seen a nexus between people in power and private players. Acquisitions were done by invoking ‘public purpose’ and then big contracts and leases were given to private players, while unwilling sellers used to receive marginal amount. New law fixes minimum compensation and mandates ‘social impact assessment’, which is expected to bring some transparency in process.
Risks associated with Dam –
One thing is that in high seismic zones, any tremors can cause cracks in the dam and as a result embankment, barrages or High gravity structures can break. This will result in uncontrolled release of huge amount of water, more than downstream river channel can take. This can cause flash floods in downstream areas. Also, Dams can burst because of faulty foundation, poor quality of materials, overfilling of water or by sabotage.
Reservoir induced Seismicity
Other more worrying phenomena is of ‘reservoir induced seismicity’. Area under the reservoir can undergo geological change under continuous unnatural pressure of water. Water will fill up the rock fissures and change their friction levels. This has capacity to cause earthquakes in surrounding areas. Range of the affect depends upon profile and depth of the affected rocks. In 2008, 80000 people were killed in Chinese province of Sichuan.
Koyana Reservoir in Maharashtra is said to have caused earthquake in 1967, killing 117 persons.
Water logging
As water seeps down the earth under the reservoir, water table of nearby areas rises depending upon the structure of the acquafiers. It is common at some places that it rises up to the ground level causing water logging in the areas. This water logging causes damages crops and renders land useless to owners and brings hardship on owners.
Further, when water from ground comes up, it brings along salts and chemicals deposited at various depths of soil column. This is known as capillary action, which increases salinity of the upper profile of the soil. This is a nightmare for farmer.
Silting up of Dams
All rivers carry silt and gravels throughout. But when its natural flow is obstructed this silt gets deposited in reservoir and gradually it decreases capacity of the reservoir. It is said that Koyna and Hirakud reservoir’s capacity have come down by 22% and 26.5% respectively. During slack season water is too muddy to be used. This way all reservoirs unless regularly desilted are temporary and will gradually disappear.
A silting dam
Impact on Environment and Biodiversity
Reservoirs and waterlogging leads to submergence of huge quantity of flora which under water releases methane gas.
Reservoir ecosystem replaces River ecosystem which alter the temperature, oxygen composition, silt and chemical composition etc. This system generally houses invasive species which results in elimination of native species.
Downstream, river is deprived of its silt load which is very essential for regeneration and maintenance of deltas, flood plains, mangroves etc. this effects biodiversity in all these areas.
Migratory fishes lose their habitat.
Apart from this in India more than 1 crore people are directly dependent upon fishing in rivers. They are consistently at risk of losing their livelihood.
Small Hydro Power as alternative
Dams having capacity lower than 25 MW are classified as Small Dams and are favorite choice of environmentalists. These don’t need environmental impact assessment, equipment’s are cheap, even small and micro entrepreneurs can get into this business. India has about 20 GW potential and Ministry of New and Renewable Energy is administering ‘Small Hydro Power program’ which aims to exploit 50 % of potential within next 10 years
This model will be more egalitarian as local population will not be displaced and instead will be immediate beneficiary of the project. This if implemented will result in decentralization of hydro power sector.
Diplomacy over Trans Boundary Rivers
Sharing of the river water has been contentious issue among the countries sharing international rivers. Two of the important perennial international Rivers i.e. Indus and Brahmaputra are have invoked much concern. International law is there – ‘UN convention on Non- navigational use of International Watercourse’, but it is not yet ratified. This ‘law’ requires states to observe equity in use, development and protection of ‘international watercourse’. But in reality every country pursues its own interests which are political and strategic, ignoring these principles.
With Pakistan and China, water sharing problem have potential of getting escalated to a conflict. Contrastingly, with Nepal, Bhutan and Bangladesh problems can sorted out with more mutual engagement and confidence building.
Indo- Pakistan River cooperation
Indus Water Treaty is considered to be one of the world’s most unequal treaties. India has right over only around 20% of water use of Indus river system. Pakistan under treaty is allowed to dominantly use western rivers ( Indus, Jhelum, Chenab) which carries about 80 % of total water flow of Indus River System (6 main rivers). It is very necessary to renegotiate or modify to have better deal as current system doesn’t take into account aspirations of people of Jammu and Kashmir. It gives an impression that interests of Jammu and Kashmir have been compromised in favor of Punjab, Haryana and Rajasthan. This is because only western rivers (which belong to Pakistan) flow through J&K, while Ravi, Beas, Sutlej which belongs to India flows through other states.
There is clause in treaty which leaves space for modification as per changing time. But it is unlikely that Pakistan will agree to any modification in India’s favor.
Some argue that, as per international practices, India can reasonably abrogate Treaty taking into account Pakistan sponsored terrorism and price that India has paid for that. India can in future quantify this loss and demand compensation from Pakistan. On non-payment it can rescind Indus water Treaty.
Indo-China River Cooperation
After China took control of Tibet in 1950’s, it automatically established its hegemony over South Asian and East Asian Rivers. Tibet is world’s largest water power house. Indus, Sutlej, Brahmaputra and three main tributaries of Ganga i.e. Karnali, Gandak and Kosi – Originates in Tibet. In past few years China has consciously shifted its focus of dam building on International Rivers. Yarlung Tsangpo, which is Brahmaputra in India) originates south of Mount Kailas, flows in south east direction. On reaching north of Arunachal Pradesh, It takes sharp Hairpin turn (Great Bend) over the Namcha Barwa Mountain and then enters India. It is said that China has plans to divert water before this bend toward South East China. There are some 30 small and large hydro projects going on Brahmaputra in China. On Sutlej River it has built Barrages and also dams are there on Indus River (In POK too). In all this China blatantly disregarded International Law which call for cooperation and Information sharing with downstream states. Hence, India remains formally uninformed and unconsulted about any development on upstream of these rivers.
Arunachal Pradesh too is blessed with immense hydro potential (50000 MW) and this Interest might be behind China’s claim to the Indian state.
India needs to create international awareness upon the issue, while making regular calls for treatment of Tibetan water resources as common resource through diplomatic channels.
India also needs to sensitize Pakistan and Bangladesh about this as they will bear the ultimate loss being last nations at downstream of these rivers.
India- Bangladesh River Cooperation
Important common rivers to two countries are Ganga, Brahmaputra, Teesta and Barak. Water sharing for these rivers is strong emotive political issue in Bangladesh. So far only Ganga water Treaty has been agreed upon and others are in process of negotiation. This treaty is at times resented in Bangladesh as it mandates sharing of water only for 1st six months of the year. Further, Indian plan for interlinking of rivers is causing apprehensions to Bangladeshis. Yet India has ensured Bangladesh that its river interlinking project, if any, won’t include Ganga and Brahmaputra.
Teesta River Issue
This river originates in Sikkim and is called lifeline of Sikkim. It enters West Bengal and finally to Bangladesh, where it merges with Brahmaputra. About 750000 hectares of Bangladesh are solely dependent on Teesta for irrigation. India has built a barrage which diverts water before river enters Bangladesh. Subject matter of negotiation is current flow of the river. Bangladesh is obviously keen on treaty but there differences on the Indian side. Government of Bengal has repeatedly stonewalled any developments.
There is ‘Indo- Bangladesh Joint River commission’ which is functional since 1972. It has also constituted a Joint Committee of Experts on Teesta issue.
Further, Tapaimukh Dam of 1500 MW is under consideration on river Barak in Manipur. It attracted sharp protest from Bangladesh. Currently any work is suspended to give time to Bangladesh to conduct environmental Studies.
India – Nepal River cooperation
Nepal is water surplus country. Main rivers are Gandak, Sapt Kosi, Karnali and Mahakali (Sharda in India).River cooperation is necessary for hydro power and flood control. Kosi River brings annual disaster both in Nepal and India which can only be controlled by mutual cooperation.
Lot of perennial river flow in Nepal from Himalayas, which results in hydroelectricity potential of 75000MW out of which 40000 MW is viably exploitable. But Nepal’s present Installed capacity is only 600 MW, 150 mw is supplied by India. Kosi agreement of 1954 and Gandak Agreement of 1959 are in place and have caused resentment in Nepal claiming unequal treatment.
3 megaprojects Sapt kosi, Karnali-Chisapani, Pancheshwar-Mahakali are in progress whose total capacity will be 22500 MW. These are languishing from about 30 years. Also, Indian companies got licenses for 27 projects but so far no progress is there.
Pancheshwar Multipurpose River Project on Mahakali River, which is on border –will be prioritized as per statement of External Affair Minister Sushma Swaraj after recent visit.
Recently China expressed its willingness to invest in Hydropower in Nepal. Power transmission from Nepal to China is unviable/impractical. So, India can explore possibility of Nepal-India – China partnership in hydro power with India and Nepal as end user and china getting adequate return on investment.
Political instability in Nepal is major factor in slow progress. Further, Communists in Nepal have time and again obstructed any progress.
India Bhutan River Cooperation
India Bhutan river cooperation is non problematic and rewarding for both countries. It power capacity in around 1500 MW and domestic need is as low as 300-400 MW. Rest of power is exported to India. India provides finance to Bhutan or directly engages in Hydropower plant construction, with commitment to purchase all the surplus power. Power Sector constitutes about 19 % of Bhutan’s GDP and 45 % of its national revenues. Potential in Bhutan is of 30000 MW and it has target of power exports to India of 10000 MW by 2020.