Sardar Sarovar Dam: Analysis of Structural Symphony

Sardar Sarovar Dam: Analysis of Structural Symphony

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Sardar Sarovar Dam

Demand for water is steadily increasing throughout the world. There is no life on earth without water, our most important resource apart from air and land. During the past three centuries, the amount of water withdrawn from freshwater resources has increased by a factor of 35, world population by a factor of 8. With the present world population of 5.6 billion still growing at a rate of about 90 million per year, and with their legitimate expectations of higher standards of living, global water demand is expected to rise by a further 2-3 percent annually in the decades ahead.

But freshwater resources are limited and unevenly distributed. In the high-consumption countries with rich resources and a highly developed technical infrastructure, the many ways of conserving, recycling and reusing water may more or less suffice to curb further growth in supply. In many other regions, however, water availability is critical to any further development above the present unsatisfactorily low level, and even to the mere survival of existing communities or to meet the continuously growing demand originating from the rapid increase of their population. In these regions man cannot forego the contribution to be made by dams and reservoirs to the harnessing of water resources.

Seasonal variations and climatic irregularities in flow impede the efficient use of river runoff, with flooding and drought causing problems of catastrophic proportions. For almost 5,000 years dams have served to ensure an adequate supply of water by storing water in times of surplus and releasing it in times of scarcity, thus also preventing or mitigating floods With their present aggregate storage capacity of about 6 000 km3, dams clearly make a significant contribution to the efficient management of finite water resources that are unevenly distributed and subject to large seasonal fluctuations. In regard to symbolic dams Sardar Sarovar Dam stands out as an prime example of structural calibre. The foundation stone of the project was laid out by Pandit Jawaharlal Nehru on April 5, 1961.

When then prime minister, Jawaharlal Nehru, laid the foundation of the Sardar Sarovar Dam in 1961, Narendra Modi was an 11-year-old boy. Now on his 67th birthday, 56 years on, Modi is dedicating arguably the most controversial development project to the nation. On September 17, Modi led to  the opening of 30 gates of the dam. The reservoir is filled to its capacity of 4.73 million cubic metre (MCM). On June 17 the gates were closed to increase the height of the dam from 121.92 metres to 138.72 metres, which allows storage of 1.25 MCM. The Sardar Sarovar project was a vision of the first deputy prime minister of India, Sardar Vallabhbhai Patel.

The 1,312-kilometre-long river drains into the Arabian Sea after passing through the states of Madhya Pradesh, Maharashtra and Gujarat. The Sardar Sarovar project is supposed to provide drinking water, power and irrigation to a wider region including Rajasthan. The development came with costs, and those were to be borne by the people living in proximity of the dams, with the dammed waters inundating villages, fertile land displacing hundreds of thousands of families, and at least 13,385 hectares of forest land.

Bettering the quality of life for millions:

Sardar Sarovar Project emerges as one of the very few projects across the globe that have played a significant role in bettering the quality of life for millions. With its unique features and unparalleled dimensions, SSP has undoubtedly occupied a remarkable position on the world atlas of water resources development. Apart from its manifold benefits in terms of long term water, energy and food security and thereby sustainable development of Gujarat State, SSP has overcome many engineering and technological challenges during its journey from concept to its present stage. In true sense, it is the Engineering Marvel. TIME magazine, in 1994 described the Narmada Project as one of the “Eight Modern Wonders Abuilding”.

The Sardar Sarovar Dam is a gravity dam on the Narmada river near Navagam, Gujarat in India. Four Indian states, Gujarat, Madhya Pradesh, Maharashtra, and Rajasthan, receive water and electricity supplied from the dam. The foundation stone of the project was laid out by Prime Minister Jawaharlal Nehru on April 5, 1961. The project took form in 1979 as part of a development scheme to increase irrigation and produce hydroelectricity. The dam was inaugurated by Prime Minister Narendra Modi on September 17, 2017.

One of the 30 dams planned on river Narmada, Sardar Sarovar Dam (SSD) is the largest structure to be built. It is one of the largest dams in the world. It is a part of the Narmada Valley Project, a large hydraulic engineering project involving the construction of a series of large irrigation and hydroelectric multi-purpose dams on the Narmada river. Following a number of controversial cases before the Supreme Court of India (1999, 2000, 2003), by 2014 the Narmada Control Authority had approved a series of changes in the final height and the associated displacement caused by the increased reservoir, from the original 80 m (260 ft) to a final 163 m (535 ft) from foundation. The project will irrigate more than 18,000 km2 (6,900 sq mi), most of it in drought-prone areas of Kutch and Saurashtra.

The dam’s main power plant houses six 200 MW Francis pump-turbines to generate electricity and includes a pumped-storage capability. Additionally, a power plant on the intake for the main canal contains 550 MW Kaplan turbine-generators. The total installed capacity of the power facilities is 1,450 MW.

To the south-west Malwa plateau, the dissected hill tracts culminate in the Mathwar hills, located in Alirajpur district of Madhya Pradesh. Below these hills, Narmada river flows through a long, terrific gorge. This gorge extends into Gujarat where the river is tapped by the Sardar Sarovar dam.

 

 

The vision and the execution:

On occasion of his 67th birthday, Prime Minister Narendra Modi has inaugurated the Sardar Sarovar Dam on the Narmada river. The project which has been the subject of much controversy for decades now is reported to be one of the largest dams in the world. Having a length of 1.2 kms and a depth of 163 metres, the dam is expected to be shared among the three states of Madhya Pradesh, Maharashtra and Gujarat. “Four crore Gujaratis will get drinking water and 22,000 hectares of land will be irrigated,” claimed union minister Nitin Gadkari on the benefits of the project and added that the dam will help realise PM Modi’s dream of making poor farmers wealthy by 2022.

The Sardar Sarovar project was a vision of the first deputy prime minister of India, Sardar Vallabhbhai Patel. The foundation stone of the project was laid out by Pandit Jawaharlal Nehru on April 5, 1961 after carrying out a study on the usage of the Narmada river water that flowed through the states of Madhya Pradesh and Gujarat and into the Arabian Sea. A project report prepared for the dam led to much dispute over the means of distributing the Narmada water among the three states- Gujarat, Maharashtra and Madhya Pradesh. As the negotiations bore no fruit, a Narmada Water Dispute Tribunal (NWDT) was created in 1969 to decide the fate of the project.

Currently the height of the dam has been raised to 138.68 metres with a usable storage of 4.73 million acre feet of water. While inaugurating the dam, PM Modi performed Narmada aarti and offered prayers at the site. “There have been many who politicised the construction of the Sardar Sarovar Dam. But we overcame all conspiracies against Maa Narmada to complete the Sardar Sarovar project,” he said as he emphasised the fact that that day would have been a matter of great pride to the man who had envisioned the Sardar Sarovar Dam: Sardar Vallabhbhai Patel.

The chaotic history

The dam is one of India’s most controversial, and its environmental impact and net costs and benefits are widely debated. The World Bank was initially funding SSD, but withdrew in 1994. The Narmada Dam has been the centre of controversy and protest since the late 1980s.

One such protest takes centre stage in the Spanner Films documentary Drowned Out (2002), which follows one tribal family who decide to stay at home and drown rather than make way for the Narmada Dam. An earlier documentary film is called A Narmada Diary (1995) by Anand Patwardhan and Simantini Dhuru. The efforts of NBA to seek “social and environmental justice” for those most directly affected by the Sardar Sarovar Dam construction feature prominently in this film. It received the (Filmfare Award for Best Documentary-1996). The figurehead of much of the protest is Medha Patkar, the leader of the Narmada Bachao Andolan (“Save Narmada Movement”). The movement was cemented in 1989, and received the Right Livelihood Award in 1991.

Support for the protests also came from Indian author Arundhati Roy, who wrote “The Greater Common Good”, an essay reprinted in her book The Cost of Living, in protest of the Narmada Dam Project. In the essay, Roy states:

Height Issue

In February 1999, the Supreme Court of India gave the go ahead for the dam’s height to be raised to 88 m (289 ft) from the initial 80 m (260 ft).

In October 2000 again, in a 2-to-1 majority judgment in the Supreme Court, the government was allowed to construct the dam up to 90 m (300 ft).

In May 2002, the Narmada Control Authority approved increasing the height of the dam to 95 m (312 ft).

In March 2004, the Authority allowed a 15 m (49 ft) height increase to 110 m (360 ft).

In March 2006, the Narmada Control Authority gave clearance for the height of the dam to be increased from 110.64 m (363.0 ft) to 121.92 m (400.0 ft). This came after 2003 when the Supreme Court of India refused allow the height of the dam to increase again.

In August 2013, heavy rains raised the reservoir level to 131.5 m (431 ft), which forced 7,000 villagers upstream along the Narmada River to relocate.

On June 2014, Narmada Control Authority gave the final clearance to raise the height from 121.92 m (400.0 ft) metres to 138.68 m (455.0 ft)

The Narmada Control Authority decided on June 17 2017 to raise the height of the Sardar Sarovar Dam to its fullest height by ordering the closure of 30 Gates

Despite popular protest, the Supreme Court gave clearance for the height to be increased to 121.92 m (400 ft), but in the same judgment Justice Mr. Bharucha gave directions to Madhya Pradesh and Maharashtra (the Grievance Redressal Authorities of Gujarat) that before further construction begins, they should certify (after inspection) that all those displaced by the raise in height of 5 metres have already been satisfactorily rehabilitated, and also that suitable vacant land for rehabilitating them is already in the possession of the respective States. This process shall be repeated for every successive five metre increase in height.

Sardar Sarovar Dam an engineering miracle

Sardar Sarovar Narmada Nigam (SSNL), a state-owned company, is responsible for implementing and managing the SSP. Jaiprakash Associates was the engineering, procurement and construction contractor for the dam and powerhouse. Gujarat State Electricity Company operates and maintains the power completely.

Sardar Sarovar Dam (SSD), on the Indian Narmada river, is located in the village of Kevadia in the state of Gujarat. It is one of the largest and most controversial interstate, multipurpose river valley infrastructure development projects in the country. The Sardar Sarovar Project (SSP) also consists of auxiliary works and a 1,450MW power complex. SSP was estimated to have cost INR400bn ($8bn) in 2010-2011, revised from the initial estimate of INR 64bn ($1.25bn) in 1988. It is part of the Narmada Valley Development Project, a major plan to generate power and supply water for drinking and irrigation to states of Gujarat, Madhya Pradesh and Maharashtra.

The scheme was conceived by the late Sardar Vallabhbhai Patel in 1946-1947. It envisages the construction of 30 major dams, 135 medium and 3,000 smaller dams along the river, with SSD being the largest of them all. They are expected to generate about 4,000MW of power in total. A state-wide drinking water grid is expected to supply for about 75% of the Gujarat population. Gujarat Water Infrastructure and the Gujarat Water Supply and Sewage Board (GWSSB) are executing this Narmada Master Plan.

The 66,000km network of conveyance and distribution system includes the Narmada Main Canal (NMC), about 2,500km of branch canals, 5,500km of distributaries and other associated channels. The 458.3 km long, 1,133 cubic metres a second capacity NMC in Gujarat is the largest irrigation lined canal in the world. It further extends by 74 km in Rajasthan. It also has 38 off-taking branch canals being built in phases and is scheduled for completion by 2025.

The SSP has two hydropower generating units. The 1,200MW underground river bed power house (RBPH) station has six, 200 MW units of reversible Francis type turbines, supplied by Sumitomo and BHEL.

The 250MW surface canal head power house (CHPH) consists of five, 50MW Kaplan turbines. The CHPH power units were commissioned by December 2004 and RBPH by November 2006. The power stations are connected to a Gas Insulated Switchgear and busbars switchyard complex in RBPH. Electricity is distributed to Gujarat (16%), Madhya Pradesh (57%) and Maharashtra (27%) through a 400kV power transmission line.

Sardar Sarovar Dam also known as “Narmada Dam” is the largest dam to be built, with a height of 163 meters, over the Sacred Narmada River in Gujarat. Drought prone areas of Kutch and Saurashtra will get irrigate by this project. The gravity dam is the largest dam of Narmada Valley Project with power facilities up to 200 MW. The dam is meant to benefit the 4 major states of India Gujarat, Madhya Pradesh, Maharashtra and Rajasthan.

  • Height: 163 meters
  • Length:1,210 meters
  • Type: Gravity Dam
  • Reservoir Capacity: 7,701,775 acre·ft
  • River: Narmada River
  • Location: Gujarat
  • Installed capacity: 1,450 MW
  • Engineering and alignment

Sardar Sarovar Dam is a concrete gravity dam across river Narmada, 1210 meters (3970 feet) in length and with a maximum height of 163 meters above the deepest foundation level, is constructed upto the crest level of spillway i.e. 121.92 m.

It is the third highest concrete dam (163 meters) in India, the first two being Bhakra (226 metres) in Himachal Pradesh and Lakhwar (192 meters) in Uttar Pradesh. Some of the noteworthy achievements in the de-sign and execution comprise River Diversion Scheme, Submersible Cofferdams under flowing water conditions across deep river channel, excavation of open cut diversion channel, providing gated construction sluices etc.

Treatment of geological fault in the dam foundation involved 2,14,000 m3 of excavation, 2,50,000 m3 of rock excavation, 2,56,000 m3 of pre-cooled concrete and 53,000 tonnes of reinforcement steel. Treatment of argillaceous sandstone in two layers on the right bank and red bole layer on the left bank was carried out by providing a grid of concrete shear keys (3.0 m wide and 3.5 m deep) parallel and perpendicular to the dam axis aggregating to 12 km length. With such a vigorous treatment, the design of the dam allows for a horizontal seismic coefficient of 0.125g and it also covers an additional risk due to reservoir induced seismicity. Thus foundation treatment itself was more challenging than construction of any major dam.

In terms of the volume of concrete involved for gravity dams, this is ranking as the second largest in the world with an aggregate volume of 6.82 million m3. The first is Grand Coule Dam in USA with a total volume of 8.0 million m3. For mass concreting, a vibratory Grizzly with 2 feed hoppers, 2 Grizzly feeders, 2 Two-way Gates, 1 Jaw-crusher and 4 conveyor belts inclined at a maximum angle of 15o running at a speed of 1.5-2.0 m/s was installed. The capacity of conveyor belt system used was 1000 tonnes/hr and it had a total length of 4.5 km. In the Aggregate Screening Plant, 2 reclamation tunnels each having 5 electrically operated vibro-feeders of 500 tonnes per hour were used. 6 Nos. of Cement Silos with total capacity of 12000 tonnes were used for storage of bulk cement using pneumatic pressure. To take care of heat of hydration during mass concreting, a Chilling Plant comprising 6 Chillers with total installed capacity of 1350 tonnes of refrigeration was used along with an Ice Plant consisting of 8 Ice Makers with aggregate installed capacity of 300 tonnes per day of flaked ice. A fully automatic computerized Batching and Mixing Plant (imported from CIFA, Italy) with production capacity of 330m3/hour was used. Two Cable Cranes used for placing the concrete  each having 28 tonne capacity and spanning more than 1.5 km were the longest ever in the world.

This dam with its spillway discharging capacity of 87,000 m3 /second (30.70 lac), will be the third in the world, Gazenba (1,13,000 m3 /second) in China and Tucurri (1,00,000 m3 /second) in Brazil being the first two. For chute spillway, 7 Radial gates each having size 60′ x 60′ and for service spillway, 23 Radial gates of size 60′ x 55′ are to be provided to negotiate the design flood. The River Bed Power House with an installed capacity of 1200 MW is an underground power house stationed on the right bank of the river located about 165 meters downstream of the dam. It has six number of Francis type reversible turbine generators each of 200 MW installed capacity, supplied by M/S Sumitomo Corporation, Japan and M/S BHEL. The CHPH is a surface power station in a saddle dam on right bank of the reservoir having total installed capacity of 250 MW (5 x 50 MW). These five units have been commissioned in a phased manner during Aug-04 to Dec-04. These units can be operated with minimum reservoir water level of 110.18 meters.

Narmada Main Canal

The Narmada Main Canal, having a length of 458 km in Gujarat and further extended to 74 km in Rajasthan, is world’s largest concrete lined canal with discharge carrying capacity of 1133 m3 /second (40,000 cusecs) at its head. This canal designed to annually convey 11.7 BCM of water to quench the thirst of Gujarat and Rajasthan has been completed and water has been flowing all through since March 2008. It is envisaged to use this canal not only for conveyance but also for storage of water to improve the response time of the system. At full supply depth, this canal can store 220 MCM of water a volume which can serve domestic needs of a mega city like Ahmedabad for the entire year! This storage available round the clock is even more than the capacity of dams like Watrak and Bhadar of Gujarat State.

Effectivity of the dam:

Irrigation:

Presently, irrigated land covers about 277 million hectares i.e. about 18% of world’s arable land but is responsible for around 40% of crop output and employs nearly 30% of population spread over rural areas. With the large population growth expected for the next decades, irrigation must be expanded to increase the food capacity production. It is estimated that 80% of additional food production by the year 2025 will need to come from irrigated land. Even with the widespread measures to conserve water by improvements in irrigation technology, the construction of more reservoir projects will be required.

Hydropower:

Hydroelectric power plants generally range in size from several hundred kilowatts to several hundred megawatts, but a few enormous plants have capacities near 10,000 megawatts in order to supply electricity to millions of people. World hydroelectric power plants have a combined capacity of 675,000 megawatts that produces over 2.3 trillion kilowatt-hours of electricity each year; supplying 24 percent of the world’s electricity. In many countries, hydroelectric power provides nearly all of the electrical power. In 1998, the hydroelectric plants of Norway and the Democratic Republic of the Congo (formerly Zaire) provided 99 percent of each country’s power; and hydroelectric plants in Brazil provided 91 percent of total used electricity. Electricity generated from dams is by very far the largest renewable energy source in the world. More than 90% of the world’s renewable electricity comes from dams. Hydropower also offers unique possibilities to manage the power network by its ability to quickly respond to peak demands. Pumping-storage plants, using power produced during the night, while the demand is low, is used to pump water up to the higher reservoir. That water is then used during the peak demand period to produce electricity. This system today constitute the only economic mass storage available for electricity.

Domestic and industrial use:

It has been stressed how essential water is for our civilization. It is important to remember that of the total rainfall falling on the earth, most falls on the sea and a large portion of that which falls on earth ends up as runoff. Only 2% of the total is infiltrated to replenish the groundwater. Properly planned, designed and constructed and maintained dams to store water contribute significantly toward fulfilling our water supply requirements. To accommodate the variations in the hydrologic cycle, dams and reservoirs are needed to store water and then provide more consistent supplies during shortages.

Inland navigation:

Natural river conditions, such as changes in the flow rate and river level, ice and changing river channels due to erosion and sedimentation, create major problems and obstacles for inland navigation. The advantages of inland navigation, however, when compared with highway and rail are the large load carrying capacity of each barge, the ability to handle cargo with large-dimensions and fuel savings. Enhanced inland navigation is a result of comprehensive basin planning and development utilizing dams, locks and reservoirs which are regulated to provide a vital role in realizing regional and national economic benefits. In addition to the economic benefits, a river that has been developed with dams and reservoirs for navigation may also provide additional benefits of flood control, reduced erosion, stabilized groundwater levels throughout the system and recreation.

Flood control:

Dams and reservoirs can be effectively used to regulate river levels and flooding downstream of the dam by temporarily storing the flood volume and releasing it later. The most effective method of flood control is accomplished by an integrated water management plan for regulating the storage and discharges of each of the main dams located in a river basin. Each dam is operated by a specific water control plan for routing floods through the basin without damage. This means lowering of the reservoir level to create more storage before the rainy season. This strategy eliminates flooding. The number of dams and their water control management plans are established by comprehensive planning for economic development and with public involvement. Flood control is a significant purpose for many of the existing dams and continues as a main purpose for some of the major dams of the world currently under construction.

Conclusions

Sardar Sarovar Dam  provide a range of economic, environmental, and social benefits, including recreation, flood control, water supply, hydroelectric power, waste management, river navigation, and wildlife habitat.

References

  • http://www.financialexpress.com
  • https://www.ndtv.com
  • http://indianexpress.com
  • https://economictimes.
  • http://www.sardarsarovardam.org
  • http://www.icold-cigb.net/GB/dams

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