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43-688: The Tehri Dam is a multi-purpose rock and earth-fill embankment dam on the Bhagirathi River in New Tehri , Tehri Garhwal district in Uttarakhand , India . 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 complex. The dam begun construction in 1978 and

86-599: A court case which ran in the Supreme Court for over a decade, work resumed at the Tehri Dam in 2001, after which he was arrested on 24 April 2001. Eventually, the dam reservoir started filling up in 2004, and on 31 July 2004, he was finally evacuated to new accommodation at Koti. Later he shifted to the capital city of Uttarakhand, Dehradun , and began living there with his wife. On 8 September 1983, Pandurang Hegde, an environmental activist from Karnataka, started

129-418: A dam and the filling of the reservoir behind it places a new weight on the floor and sides of a valley. The stress of the water increases linearly with its depth. Water also pushes against the upstream face of the dam, a nonrigid structure that under stress behaves semiplastically, and causes greater need for adjustment (flexibility) near the base of the dam than at shallower water levels. Thus the stress level of

172-422: A drain layer to collect seep water. A zoned-earth dam has distinct parts or zones of dissimilar material, typically a shell of locally plentiful material with a watertight clay core. Modern zoned-earth embankments employ filter and drain zones to collect and remove seep water and preserve the integrity of the downstream shell zone. An outdated method of zoned earth dam construction used a hydraulic fill to produce

215-564: A major geologic fault zone. This region was the site of a 6.8 magnitude earthquake in October 1991, with an epicenter 53 km (33 mi) 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

258-439: 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. Since 2005, filling of the reservoir has led to the reduced flow of Bhagirathi water from the normal 1,000 cu ft/s (28 m/s) to a mere 200 cu ft/s (5.7 m/s). This reduction has been central to local protest against

301-404: A small sustained overtopping flow can remove thousands of tons of overburden soil from the mass of the dam within hours. The removal of this mass unbalances the forces that stabilize the dam against its reservoir as the mass of water still impounded behind the dam presses against the lightened mass of the embankment, made lighter by surface erosion. As the mass of the dam erodes, the force exerted by

344-686: A thick suspension of earth, rocks and water. Therefore, safety requirements for the spillway are high, and require it to be capable of containing a maximum flood stage. It is common for its specifications to be written such that it can contain at least a one-hundred-year flood. A number of embankment dam overtopping protection systems were developed in the early 21st century. These techniques include concrete overtopping protection systems, timber cribs , sheet-piles , riprap and gabions , Reinforced Earth , minimum energy loss weirs , embankment overflow stepped spillways , and precast concrete block protection systems. All dams are prone to seepage underneath

387-590: A watertight core. Rolled-earth dams may also employ a watertight facing or core in the manner of a rock-fill dam. The frozen-core dam is a temporary earth dam occasionally used in high latitudes by circulating a coolant through pipes inside the dam to maintain a watertight region of permafrost within it. Tarbela Dam is a large dam on the Indus River in Pakistan , about 50 km (31 mi) northwest of Islamabad . Its height of 485 ft (148 m) above

430-469: Is a 260.5 m (855 ft) high rock and earth-fill embankment dam. Its length is 575 m (1,886 ft), crest width 20 m (66 ft), and base width 1,128 m (3,701 ft). The dam creates a reservoir of 3.54 cubic kilometres (2,870,000  acre⋅ft ) with a surface area of 52 km (20 sq mi). The installed hydrocapacity is 1,000 MW along with an additional 1,000 MW of pumped storage hydroelectricity . The lower reservoir for

473-421: Is blasted using explosives to break the rock. Additionally, the rock pieces may need to be crushed into smaller grades to get the right range of size for use in an embankment dam. Earth-fill dams, also called earthen dams, rolled-earth dams or earth dams, are constructed as a simple embankment of well-compacted earth. A homogeneous rolled-earth dam is entirely constructed of one type of material but may contain

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516-415: Is distributed to Uttar Pradesh , Uttarakhand , Punjab , Delhi , Haryana , Jammu and Kashmir , Chandigarh , Rajasthan and Himachal Pradesh . The complex will afford irrigation to an area of 270,000 hectares (670,000 acres), irrigation stabilization to an area of 600,000 hectares (1,500,000 acres), and a supply of 270 million imperial gallons (1.2 × 10 ^  m) of drinking water per day to

559-518: 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. On 21 November 2019, the Government of India approved the take over of Tehri Hydro Development Corporation (THDC) by NTPC Limited . Embankment dam Embankment dams come in two types: the earth-filled dam (also called an earthen dam or terrain dam ) made of compacted earth, and

602-585: Is generating around 3,000 GWh annually from this dam. 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

645-417: The rock-filled dam . A cross-section of an embankment dam shows a shape like a bank, or hill. Most have a central section or core composed of an impermeable material to stop water from seeping through the dam. The core can be of clay, concrete, or asphalt concrete . This type of dam is a good choice for sites with wide valleys. They can be built on hard rock or softer soils. For a rock-fill dam, rock-fill

688-654: The Appiko (Kannada for Chipko, "to hug") movement to protest against the felling of trees, monoculture , and deforestation in the Western Ghats , deriving inspiration from Sunderlal Bahugana and the Chipko movement. Bahuguna had visited the region in 1979 to help in the campaign against the proposed Bedthi hydroelectric project. After the Appiko movement started, Bahuguna and Pandurang Hegde walked across many parts of south India promoting conservation of ecology, especially

731-562: 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 , but this was interrupted years later with political instability. India

774-458: The U.S. Bureau of Reclamation Sunderlal Bahuguna Sunderlal Bahuguna (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 Vimla Bahuguna and him. He fought for the preservation of forests in the Himalayas , first as a member of the Chipko movement in the 1970s, and later spearheaded

817-633: The age of 13, under the guidance of Shri Dev Suman , who was a nationalist spreading a message of non-violence, and he was with the Congress Party of Uttar Pradesh at the time of Independence. Bahuguna also mobilised people against colonial rule before 1947. He adopted Gandhian principles in his life and married his wife Vimla with the condition that they would live among rural people and establish ashram in village. Inspired by Gandhi, he walked through Himalayan forests and hills, covering more than 4,700 kilometres (2920 miles) on foot and observed

860-651: The anti- Tehri Dam movement from the 1980s to early 2004. He was one of the early environmentalists of India, and later he and others associated with the Chipko movement and started taking up wider environmental issues, such as being opposed to large dams. Sunderlal Bahuguna was born in the village Maroda near Tehri , Uttarakhand . He claimed in a function arranged at Kolkata, that his ancestors bearing surname Bandyopadhyaya, migrated from Bengal to Tehri, 800 years ago. Early on, he fought against untouchability and later started organising hill women in his anti-liquor drive from 1965 to 1970. He started social activities at

903-637: The asphalt make such dams especially suited to earthquake regions. For the Moglicë Hydro Power Plant in Albania the Norwegian power company Statkraft built an asphalt-core rock-fill dam. Upon completion in 2018 the 320 m long, 150 m high and 460 m wide dam is anticipated to be the world's highest of its kind. A concrete-face rock-fill dam (CFRD) is a rock-fill dam with concrete slabs on its upstream face. This design provides

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946-466: The banks of Bhagirathi as a mark of his protest. In 1995, he called off a 45-day-long fast following an assurance from the then Prime Minister P. V. Narasimha Rao of the appointment of a review committee on the ecological impacts of the dam. Thereafter he went on another long fast which lasted for 74 days at Gandhi Samadhi, Raj Ghat , during the tenure of Prime Minister H. D. Deve Gowda , who gave personal undertaking of project review. However, despite

989-549: The concrete slab as an impervious wall to prevent leakage and also a structure without concern for uplift pressure. In addition, the CFRD design is flexible for topography, faster to construct and less costly than earth-fill dams. The CFRD concept originated during the California Gold Rush in the 1860s when miners constructed rock-fill timber-face dams for sluice operations . The timber was later replaced by concrete as

1032-406: The core is separated using a filter. Filters are specifically graded soil designed to prevent the migration of fine grain soil particles. When suitable building material is at hand, transport is minimized, leading to cost savings during construction. Rock-fill dams are resistant to damage from earthquakes . However, inadequate quality control during construction can lead to poor compaction and sand in

1075-406: The dam must be calculated in advance of building to ensure that its break level threshold is not exceeded. Overtopping or overflow of an embankment dam beyond its spillway capacity will cause its eventual failure . The erosion of the dam's material by overtopping runoff will remove masses of material whose weight holds the dam in place and against the hydraulic forces acting to move the dam. Even

1118-490: The dam, but embankment dams are prone to seepage through the dam as well; for example, the Usoi landslide dam leaks 35-80 cubic meters per second. Sufficiently fast seepage can dislodge a dam's component particles, which results in faster seepage, which turns into a runaway feedback loop that can destroy the dam in a piping-type failure. Seepage monitoring is therefore an essential safety consideration. gn and Construction in

1161-519: The dam, since the Bhagirathi is considered part of the sacred Ganges whose waters are crucial to Hindu 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

1204-537: The damage done by mega developmental projects on the fragile ecosystem of the Himalayas and subsequent degradation of social life in villages. The Chipko movement started in the early 1970s in Uttarakhand (then a part of Uttar Pradesh) from spontaneous action by villagers to save trees from being cut down by forest contractors. In Hindi, "chipko" literally means "to cling", and the movement got this name since

1247-456: The design was applied to irrigation and power schemes. As CFRD designs grew in height during the 1960s, the fill was compacted and the slab's horizontal and vertical joints were replaced with improved vertical joints. In the last few decades, design has become popular. The tallest CFRD in the world is the 233 m-tall (764 ft) Shuibuya Dam in China , completed in 2008. The building of

1290-578: The embankment which can lead to liquefaction of the rock-fill during an earthquake. Liquefaction potential can be reduced by keeping susceptible material from being saturated, and by providing adequate compaction during construction. An example of a rock-fill dam is New Melones Dam in California or the Fierza Dam in Albania . A core that is growing in popularity is asphalt concrete . The majority of such dams are built with rock and/or gravel as

1333-586: The industrialized areas of Delhi , Uttar Pradesh and Uttarakhand . The total expenditure for this project was US$ 1 billion. 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.

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1376-493: The movement. He had an appointment with the then Indian Prime Minister Indira Gandhi and that meeting is credited with resulting in Gandhi's subsequent 15-year ban on cutting of green trees in 1980. He was also closely associated with Gaura Devi , one of the pioneers of the movement. Bahuguna played a major role in the anti- Tehri Dam protests for decades. He used Satyagraha methods and repeatedly went on hunger strikes at

1419-487: The people trying to save the trees started hugging and Loving onto trees when lumbermen tried to fall those. One of Sunderlal Bahuguna's notable contributions to the Chipko movement, and to environmentalism in general, was his creation of the Chipko's slogan "Ecology is permanent economy". Sunderlal Bahuguna helped bring the movement to prominence through a 5,000-kilometer trans-Himalaya march undertaken from 1981 to 1983, travelling from village to village, gathering support for

1462-424: The primary fill. Almost 100 dams of this design have now been built worldwide since the first such dam was completed in 1962. All asphalt-concrete core dams built so far have an excellent performance record. The type of asphalt used is a viscoelastic - plastic material that can adjust to the movements and deformations imposed on the embankment as a whole, and to settlement of the foundation. The flexible properties of

1505-780: The protection of the Western Ghats, a biodiversity hotspot . This and the broader Save the Western Ghats Movement led to a moratorium on green felling across the region in 1989. While best known as an environmental activist and as a passionate defender of the Himalayan people and India's rivers, Bahuguna also worked to improve the plight of the hill people, especially working women, and was associated with temperance movements and earlier on with struggles against casteist discrimination. Bahuguna died on 21 May 2021, due to COVID-19 complications. Shortly after, he

1548-647: 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 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

1591-501: The reservoir begins to move the entire structure. The embankment, having almost no elastic strength, would begin to break into separate pieces, allowing the impounded reservoir water to flow between them, eroding and removing even more material as it passes through. In the final stages of failure, the remaining pieces of the embankment would offer almost no resistance to the flow of the water and continue to fracture into smaller and smaller sections of earth or rock until they disintegrate into

1634-399: The river bed and 95 sq mi (250 km ) reservoir make it the largest earth-filled dam in the world. The principal element of the project is an embankment 9,000 feet (2,700 m) long with a maximum height of 465 feet (142 m). The dam used approximately 200 million cubic yards (152.8 million cu. meters) of fill, which makes it one of the largest man-made structures in

1677-404: The upstream face and made of masonry , concrete , plastic membrane, steel sheet piles, timber or other material. The impervious zone may also be inside the embankment, in which case it is referred to as a "core". In the instances where clay is used as the impervious material, the dam is referred to as a "composite" dam. To prevent internal erosion of clay into the rock fill due to seepage forces,

1720-414: The world. Because earthen dams can be constructed from local materials, they can be cost-effective in regions where the cost of producing or bringing in concrete would be prohibitive. Rock -fill dams are embankments of compacted free-draining granular earth with an impervious zone. The earth used often contains a high percentage of large particles, hence the term "rock-fill". The impervious zone may be on

1763-565: Was against the displacement of town inhabitants and environmental consequence of the weak ecosystem. 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 of the Himalayan foothills. There are further concerns regarding the dam's geological stability. The Tehri dam is in the Central Himalayan Seismic Gap,

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1806-502: Was completed in 2006. It withholds a reservoir for irrigation , municipal water supply and the generation of 1,000 megawatts (1,300,000 hp) 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. A preliminary investigation for

1849-565: 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 . 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. Tehri Dam

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