The Tehri Dam is a multi-purpose rock and earth-fill

embankment dam An embankment dam is a large artificial dam. It is typically created by the placement and compaction of a complex semi-plastic mound of various compositions of soil or rock. It has a semi-pervious waterproof natural covering for its surface ...

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 f ...

in New Tehri, Tehri Garhwal district in

Uttarakhand Uttarakhand (, ), also known as Uttaranchal ( ; List of renamed places in India, the official name until 2007), is a States and union territories of India, state in North India, northern India. The state is bordered by Himachal Pradesh to the n ...

India India, officially the Republic of India, 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 by population (United Nations), most populous country since ...

. With a height of 260.5 m (855 ft), it is the tallest dam in India and the 13th-tallest dam in the world. It is the primary dam of THDC India Ltd. and the Tehri

hydroelectric Hydroelectricity, or hydroelectric power, is Electricity generation, electricity generated from hydropower (water power). Hydropower supplies 15% of the world's electricity, almost 4,210 TWh in 2023, which is more than all other Renewable energ ...

complex. The dam begun construction in 1978 and was completed in 2006. It withholds a reservoir for

irrigation Irrigation (also referred to as watering of plants) 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 bee ...

, 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 the commissioning of the first two units was expected to be completed in 2023, which got finished in March 2024, and the rest to be done by 2025.

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 Union of Soviet Socialist Republics. (USSR), commonly known as the Soviet Union, was a List of former transcontinental countries#Since 1700, transcontinental country that spanned much of Eurasia from 1922 until Dissolution of the Soviet ...

, 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 ( ; UP) is a States and union territories of India, state in North India, northern India. With over 241 million inhabitants, it is the List of states and union territories of India by population, most populated state in In ...

. 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 (; ; also romanised as Panjāb or Panj-Āb) is a geopolitical, cultural, and historical region in South Asia. It is located in the northwestern part of the Indian subcontinent, comprising areas of modern-day eastern Pakistan and no ...

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, but spread chiefly to the west, or beyond its Bank (geography ...

Haryana Haryana () is a States and union territories of India, state located in the northern part of India. It was carved out after the linguistic reorganisation of Punjab, India, Punjab on 1 November 1966. It is ranked 21st in terms of area, with les ...

, Jammu and Kashmir,

Chandigarh Chandigarh is a city and union territory in northern India, serving as the shared capital of the states of Punjab and Haryana. Situated near the foothills of the Shivalik range of Himalayas, it borders Haryana to the east and Punjab in the ...

Rajasthan Rajasthan (; Literal translation, lit. 'Land of Kings') is a States and union territories of India, state in northwestern India. It covers or 10.4 per cent of India's total geographical area. It is the List of states and union territories of ...

and

Himachal Pradesh Himachal Pradesh (; Sanskrit: ''himācāl prādes;'' "Snow-laden Mountain Province") is a States and union territories of India, state in the northern part of India. Situated in the Western Himalayas, it is one of the thirteen Indian Himalayan ...

. 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$ The United States dollar (Currency symbol, symbol: Dollar sign, $; ISO 4217, currency code: USD) is the official currency of the United States and International use of the U.S. dollar, several other countries. The Coinage Act of 1792 introdu ...

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 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) is a system formed by Organism, organisms in interaction with their Biophysical environment, environment. The Biotic material, biotic and abiotic components are linked together through nutrient cycles and en ...

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 Earth's highest peaks, including the highest, Mount Everest. More than 100 pea ...

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 In geology, a fault is a planar fracture or discontinuity in a volume of rock across which there has been significant displacement as a result of rock-mass movements. Large faults within Earth's crust result from the action of plate tectonic ...

zone. This region was the site of a 6.8

magnitude Magnitude may refer to: Mathematics *Euclidean vector, a quantity defined by both its magnitude and its direction *Magnitude (mathematics), the relative size of an object *Norm (mathematics), a term for the size or length of a vector *Order of ...

earthquake An earthquakealso called a quake, tremor, or tembloris the shaking of the Earth's surface resulting from a sudden release of energy in the lithosphere that creates seismic waves. Earthquakes can range in intensity, from those so weak they ...

in October 1991, with an

epicenter The epicenter (), epicentre, or epicentrum in seismology is the point on the Earth's surface directly above a hypocenter or focus, the point where an earthquake or an underground explosion originates. Determination The primary purpose of a ...

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. 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 (; ; also known as Sanātanīs) are people who religiously adhere to Hinduism, also known by its endonym Sanātana Dharma. Jeffery D. Long (2007), A Vision for Hinduism, IB Tauris, , pp. 35–37 Historically, the term has also be ...

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 15919, ISO: Bhārata Sarakāra, legally the Union Government or Union of India or the Central Government) is the national authority of the Republic of India, located in South Asia, consisting of States and union t ...

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

NTPC Limited NTPC Limited, formerly known as National Thermal Power Corporation, is an Indian central Public Sector Undertaking (PSU) under the ownership of the Ministry of Power and the Government of India, who is engaged in the generation of electricit ...

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 Ganges Tehri Garhwal district