With a height of 260.5 m (855 ft) Tehri Dam is the tallest dam in India and 12th tallest dam in the world. With a total planned installed capacity of 2400 MW, it's the biggest Hydroelectric power plant in India. It is a multi-purpose rock and earth-fill embankment dam on the

Bhagirathi River The Bhāgīrathī (Pron: /ˌbʌgɪˈɹɑːθɪ/) is a turbulent Himalayan river in the Indian state of Uttarakhand, and one of the two headstreams of the Ganges, the major river of Northern India and the holy river of Hinduism. In the Hindu ...

New Tehri New Tehri is a city and a municipal board in Tehri Garhwal District in the Indian state of Uttarakhand. It is the administrative headquarters of Tehri Garhwal District. This urban municipality area has 11 wards, from Vidhi Vihar to Vishwakar ...

, Tehri Garhwal district in

Uttarakhand Uttarakhand ( , or ; , ), also known as Uttaranchal ( ; the official name until 2007), is a state in the northern part of India. It is often referred to as the "Devbhumi" (literally 'Land of the Gods') due to its religious significance and ...

India India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the List of countries and dependencies by area, seventh-largest country by area, the List of countries and dependencies by population, second-most populous ...

. It is the primary dam of the THDC India Ltd. and the Tehri

hydroelectric Hydroelectricity, or hydroelectric power, is electricity generated from hydropower (water power). Hydropower supplies one sixth of the world's electricity, almost 4500 TWh in 2020, which is more than all other renewable sources combined an ...

complex. Phase 1 was completed in 2006. The Tehri Dam withholds a reservoir for

irrigation Irrigation (also referred to as watering) is the practice of applying controlled amounts of water to land to help grow crops, landscape plants, and lawns. Irrigation has been a key aspect of agriculture for over 5,000 years and has been devel ...

, municipal water supply and the generation of of hydroelectricity. The dam's 1,000 MW variable-speed pumped-storage scheme is currently under construction with expected commissioning of first two units in 2023.

History

A preliminary investigation for the Tehri Dam Project was completed in 1961 under Jawahar lal Nehru's ministry's and its design was completed in 1972 with a 600 MW capacity power plant based on the study. Construction began in 1978 after feasibility studies but was delayed due to financial, environmental and social impacts. In 1986, technical and financial assistance was provided by the

USSR The Soviet Union,. officially the Union of Soviet Socialist Republics. (USSR),. was a transcontinental country that spanned much of Eurasia from 1922 to 1991. A flagship communist state, it was nominally a federal union of fifteen nati ...

, but this was interrupted years later with political instability. India was forced to take control of the project and at the first, it was placed under the direction of the Irrigation Department of

Uttar Pradesh Uttar Pradesh (; , 'Northern Province') is a state in northern India. With over 200 million inhabitants, it is the most populated state in India as well as the most populous country subdivision in the world. It was established in 195 ...

. However, in 1988 the Tehri Hydro Development Corporation was formed to manage the dam and 75% of the funding would be provided by the federal government, 25% by the state. Uttar Pradesh would finance the entire irrigation portion of the project.

Technical description

Tehri Dam is a high rock and earth-fill embankment dam. Its length is , crest width , and base width . The dam creates a reservoir of with a surface area of . The installed hydrocapacity is 1,000 MW along with an additional 1,000 MW of pumped storage hydroelectricity. The lower reservoir for the pumped-storage plant is created by the Koteshwar Dam downstream. The Tehri Dam and the Tehri Pumped Storage Hydroelectric Power Plant are part of the Tehri Hydropower Complex which also includes the 400 MW Koteshwar Dam.Tehri Dam: An Engineering Marvel, by Basistha Raj Adhikari
/ref> Tehri pumped storage plant (4 X 250 MW) has variable speed features which can optimize the round trip efficiency under varying water levels in its reservoirs. Power is distributed to

Punjab Punjab (; Punjabi Language, Punjabi: پنجاب ; ਪੰਜਾਬ ; ; also Romanization, romanised as ''Panjāb'' or ''Panj-Āb'') is a geopolitical, cultural, and historical region in South Asia, specifically in the northern part of the I ...

Delhi Delhi, officially the National Capital Territory (NCT) of Delhi, is a city and a union territory of India containing New Delhi, the capital of India. Straddling the Yamuna river, primarily its western or right bank, Delhi shares borders w ...

Haryana Haryana (; ) is an Indian state located in the northern part of the country. It was carved out of the former state of East Punjab on 1 Nov 1966 on a linguistic basis. It is ranked 21st in terms of area, with less than 1.4% () of India's land ...

Jammu and Kashmir Jammu and Kashmir may refer to: * Kashmir, the northernmost geographical region of the Indian subcontinent * Jammu and Kashmir (union territory), a region administered by India as a union territory * Jammu and Kashmir (state), a region administered ...

Chandigarh Chandigarh () is a planned city in India. Chandigarh is bordered by the state of Punjab to the west and the south, and by the state of Haryana to the east. It constitutes the bulk of the Chandigarh Capital Region or Greater Chandigarh, which al ...

Rajasthan Rajasthan (; lit. 'Land of Kings') is a state in northern India. It covers or 10.4 per cent of India's total geographical area. It is the largest Indian state by area and the seventh largest by population. It is on India's northwestern ...

and

Himachal Pradesh Himachal Pradesh (; ; "Snow-laden Mountain Province") is a state in the northern part of India. Situated in the Western Himalayas, it is one of the thirteen mountain states and is characterized by an extreme landscape featuring several pea ...

. The complex will afford

to an area of , irrigation stabilization to an area of , and a supply of of drinking water per day to the industrialized areas of

and

. The total expenditure for this project was US$1 billion.

Scheduling and generation dispatch

The scheduling and dispatch of the Tehri Hydro Power plant is done by Northern Regional Load Dispatch Center (NRLDC), which is the apex body to ensure the integrated operation of the power system grid in the Northern region and comes under Power System Operation Corporation Limited (POSOCO). At present, THDC India Ltd. is generating around 3,000 GWh annually from this dam.

Environmental issues

The Tehri Dam has been the object of protests by environmental organizations and local people of the region. Virendra Dutt Saklani, lawyer and founder of the Anti-Tehri Dam Struggle Committee, was quick to point out the consequences associated to the large project. Environmental activist

Sunderlal Bahuguna Sunderlal Bahuguna Ji (9 January 1927 – 21 May 2021) was an Indian environmentalist and Chipko movement leader. The idea of the Chipko movement was suggested by his wife and him. He fought for the preservation of forests in the Himalayas, fi ...

led the Anti-Tehri Dam movement from 1980s till 2004. The protest was against the displacement of town inhabitants and environmental consequence of the weak ecosystem. Tehri Dam India

In addition to the human rights concerns, the project has spurred concerns about the environmental consequences of locating such a large dam in the fragile

ecosystem An ecosystem (or ecological system) consists of all the organisms and the physical environment with which they interact. These biotic and abiotic components are linked together through nutrient cycles and energy flows. Energy enters the syst ...

of the

Himalaya The Himalayas, or Himalaya (; ; ), is a mountain range in Asia, separating the plains of the Indian subcontinent from the Tibetan Plateau. The range has some of the planet's highest peaks, including the very highest, Mount Everest. Over 10 ...

n foothills. There are further concerns regarding the dam's geological stability. The Tehri dam is in the Central Himalayan Seismic Gap, a major geologic fault zone. This region was the site of a 6.8 magnitude

earthquake An earthquake (also known as a quake, tremor or temblor) is the shaking of the surface of the Earth resulting from a sudden release of energy in the Earth's lithosphere that creates seismic waves. Earthquakes can range in intensity, fr ...

in October 1991, with an epicenter from the dam. Dam proponents claim that the complex is designed to withstand an earthquake of 8.4 magnitude, but some seismologists say that earthquakes with a magnitude of 8.5 or more could occur in this region. Were such a catastrophe to occur, the potentially resulting dam-break would submerge numerous towns downstream, whose populations total near half a million. A protest message against Tehri dam, Garhwal, Uttarakhand

A protest message against Tehri dam, Garhwal, Uttarakhand

The relocation of more than 100,000 people from the area has led to protracted legal battles over resettlement rights and, ultimately, resulted in the project's delayed completion.Terminski, Bogumil (2013). "Development-Induced Displacement and Resettlement: Theoretical Frameworks and Current Challenges", Indiana University, available at http://dlc.dlib.indiana.edu/dlc/handle/10535/8833?show=full Since 2005, filling of the reservoir has led to the reduced flow of Bhagirathi water from the normal to a mere . This reduction has been central to local protest against the dam, since the Bhagirathi is considered part of the sacred Ganges whose waters are crucial to

Hindu Hindus (; ) are people who religiously adhere to Hinduism. Jeffery D. Long (2007), A Vision for Hinduism, IB Tauris, , pages 35–37 Historically, the term has also been used as a geographical, cultural, and later religious identifier for ...

beliefs. At some points during the year, the tampering with Bhagirathi waters means this tributary stops flowing. This has created resentments among many Hindus, who claim that the sanctity of the Ganges has been compromised for the generation of electricity. The officials say that when the reservoir is filled to its maximum capacity the flow of the river will again become normal. In spite of concerns and protestation, operation of the Tehri Dam continues.

NTPC Limited Takeover

On 21 November 2019, the

Government of India The Government of India ( ISO: ; often abbreviated as GoI), known as the Union Government or Central Government but often simply as the Centre, is the national government of the Republic of India, a federal democracy located in South Asia, ...

approved the take over of Tehri Hyrdo Development Corporation (THDC) by

NTPC Limited NTPC Limited, formerly known as National Thermal Power Corporation Limited, is an Indian central public sector undertaking under the ownership of the Ministry of Power, Government of India which is engaged in generation of electricity an ...

References

Official website of the Tehri Hydro Development Corporation Limited
the organization in charge of the dam's construction

a traveller's account of Tehri dam.
Tehri Lake: Memories from Old Tehri
A Backpacker at Tehri Lake * Gaur, Vinod K. and Valdiya, K. S. (1993) ''Earthquake Hazard and Large Dams in the Himalaya'', Indian National Trust for Art and Cultural Heritage, New Delhi, * Nawani, PC et al. (2006) "TEHRI DAM PROJECT – A Geotechnical Appraisal," Geological Survey of India Bulletin: Series B, No.62,

External links

Tehri Hydro Power Complex on the Bhagirathi River in India
Journal Power Technology and Engineering (formerly Hydrotechnical Construction), Springer, New York (Print) (Online) Vol. 34, No. 8-9 / Aug, 2000 , pp 479–484, 2 November 2004 {{Authority control Dams completed in 2009 Energy infrastructure completed in 2006 Dams in Uttarakhand Hydroelectric power stations in Uttarakhand India–Soviet Union relations New Tehri Pumped-storage hydroelectric power stations in India Embankment dams Dams on the Bhagirathi River 2006 establishments in Uttarakhand Renewable energy Rivers of Uttarakhand Rigvedic rivers Rivers of India Ganges Tehri Garhwal district