Multipurpose river projects: the "temples of modern India"

Detail

1. What is a dam?

• Dam: a wall built across flowing water. It blocks the flow, sends it in a new direction or slows it down. It usually creates a reservoir (an artificial lake) behind it.
• Extra water leaves the dam over a spillway or weir (a low channel or wall that lets surplus water pass safely).
• Classification by structure and material:

Basis	Types	Indian example (from the CWC register)
Structure / material	Timber, embankment (earth or rock fill), masonry (stone or concrete)	Hirakud (earth + gravity), Bhakra (concrete gravity), Tehri (earth + gravity + rockfill) [2]
Height	Large, medium, low dams	See the "large dam" rule below

• Large dam (ICOLD rule used in India): a dam more than 15 m high, measured from its deepest foundation to its crest (top) [2].

• A dam 10–15 m high also counts if it meets one condition. The conditions are: a crest length of at least 500 m, a reservoir of at least 1 million m³, a flood discharge of at least 2,000 m³/s, a difficult foundation or an unusual design [2].

• Dams of National Importance: dams that are 100 m or higher, or that store 1 km³ (1 billion m³) or more. In 2018 India had 65 completed and 11 under construction [2].

• How many dams India has (NRLD 2018): 5,264 completed large dams and 437 under construction, a total of 5,701 [2].
• Maharashtra has the most (2,354). Next come Madhya Pradesh (906) and Gujarat (632) [2].
• Most dams were built in 1971–80 (1,288) and 1981–90 (1,304). Only 68 existed before 1900 [2].

2. Multipurpose river projects

• Multipurpose river project: one project, usually a dam, a reservoir and canals, that serves many uses together:
• irrigation
• hydropower (electricity from falling water)
• domestic and industrial water supply
• flood control
• recreation
• inland navigation

• fish breeding (pisciculture)

• Example: the CWC register gives Sardar Sarovar six coded purposes: Irrigation, Hydel, flood Control, water Supply, Navigation and Fisheries ("I/H/C/S/N&F") [2].

• Why India built them:
• India's rainfall is seasonal: most rain falls in the four monsoon months.
• So water has to be stored in the wet season and used in the dry season.
• India launched these projects after independence as part of integrated water resources management (IWRM). IWRM means planning water for all users of a river basin together.
• The Five Year Plans gave them high priority.

3. "Temples of modern India"

• Temples of modern India: Jawaharlal Nehru's name for big dams.
• His idea:
• Dams would link agriculture and the village economy with industry and the growth of cities.
• Cheap power and canal water would raise farm output and run factories.

• This would help India leave its colonial past behind, when it was poor, hit by famine and short of industry.

• The other side: from the 1960s–70s these projects faced criticism. They displaced people, flooded forests, trapped silt and caused fights between states. This is covered under the Narmada Bachao Andolan in Section 8.

4. Bhakra-Nangal project (Satluj-Beas basin)

• River: the Satluj rises near Rakas Tal (close to Mansarovar) in Tibet. It enters India at Shipki La, cuts through the Himalaya, meets the Beas at Harike (Punjab) and flows into Pakistan to join the Indus.
• Bhakra dam:
• Location: Bilaspur district, Himachal Pradesh. Completed in 1963.
• It is a concrete gravity dam: it holds water back by its own great weight. It is one of the highest dams of its kind.

• Height 226 m; length 518 m; gross storage 9.62 km³; uses: irrigation and hydel power (NRLD 2018) [2].

• Reservoir: Gobind Sagar.

• Nangal dam: a smaller dam downstream in Punjab. It turns water into the canals.
• Who benefits: hydel power and canal irrigation for Punjab, Haryana and Rajasthan.
• Linked works: the Pong dam on the Beas (1974, 133 m) [2]. The Indira Gandhi Canal starts at the Harike barrage (where the Satluj and Beas meet) and carries Satluj-Beas water into the Thar desert of Rajasthan.

5. Hirakud dam (Mahanadi)

• River: the Mahanadi rises near Sihawa (Chhattisgarh), flows east through Odisha and forms a delta on the Bay of Bengal.
• Location: near Sambalpur, Odisha. Inaugurated in 1957.
• Type: earth plus gravity (TE/PG). Height 60.96 m. The main dam is 4,800 m long. Gross storage 8.14 km³. Reservoir area 743 km². Uses: irrigation, hydel, flood control and water supply (NRLD 2018) [2].
• With its long earthen dykes (side walls), it is among the world's longest earthen dams.
• Why it matters: it stores water and controls floods in the Mahanadi delta.

6. Damodar Valley Corporation (DVC)

• Damodar Valley Corporation: set up on 7 July 1948. It was India's first multipurpose river valley authority (one body that runs dams, power, irrigation and flood control for a whole valley).
• Model: the Tennessee Valley Authority (TVA) of the USA (1933).
• The problem it solved:
• The Damodar rises on the Chota Nagpur plateau (Jharkhand) and flows east into the Hooghly (West Bengal).
• Floods in its lower course caused so much damage that it was called the "river of sorrow" (of Bengal).

• NCERT quotes a Bhadu folk song of the region about what the dams did to local people.

• Dams:

Dam	River	Year	Height (NRLD)
Tilaiya	Barakar (tributary of the Damodar)	early 1950s	—
Maithon	Barakar	1957	56 m [2]
Panchet	Damodar	1959	48 m [2]
Konar	Konar (tributary of the Damodar)	1950s	—

• The register lists Maithon and Panchet in Jharkhand, with Asansol as the nearest city. Both serve irrigation, hydel, water supply and flood control [2].
• DVC also runs thermal power stations that use Damodar-valley coal.

7. Nagarjuna Sagar (Krishna)

• On the Krishna, on the Telangana–Andhra Pradesh border. Completed in 1974.
• Earth plus gravity dam, 124.66 m high, gross storage 11.56 km³. Uses: irrigation and hydel (NRLD 2018) [2].
• It is one of India's largest masonry dams by storage.

8. Sardar Sarovar project (Narmada)

• River: the Narmada rises at Amarkantak (Madhya Pradesh). It flows west through a rift valley (a long trough formed where the land sank between two faults) between the Vindhya and Satpura ranges. It enters the Gulf of Khambhat (Arabian Sea).
• Location: Kevadia (Ekta Nagar), Narmada district, Gujarat.
• Type: concrete gravity dam.
• Timeline: foundation stone 1961 → completed 2017. The dam was raised to its final height of 138.68 m in 2017.

• The register gives 163 m as the height measured from the deepest foundation. It also gives a length of 1,210 m and a gross storage of 9.50 km³ [2].

• States served: Gujarat, Rajasthan, Madhya Pradesh and Maharashtra.

• Irrigation:
• Gujarat: 18.45 lakh ha in 3,112 villages of 15 districts. About 75% of this area is drought-prone.
• Rajasthan: 2.46 lakh ha in Barmer and Jalore.

• Maharashtra: 37,500 ha in tribal hill areas. Water is lifted there by pumps.

• Water sharing: set by the Narmada Water Disputes Tribunal award (1979).

• Conflict: large-scale displacement led to the Narmada Bachao Andolan (Section 8).

9. Newer mega-projects

Kaleshwaram Lift Irrigation Project (Godavari, Telangana)

• Lift irrigation: water is pumped uphill in stages, instead of flowing down by gravity.
• Barrages (low dams that raise the water level) collect water.
• Pumps lift it to reservoirs higher up.

• Canals then carry it to fields that sit above the river.

• River: the Godavari rises at Trimbakeshwar (Nashik, Maharashtra) and flows east to the Bay of Bengal.

• Project: inaugurated in 2019. It is one of the world's largest multi-stage lift schemes. Its three main barrages are Medigadda (Lakshmi), Annaram and Sundilla.
• Problems:
• It uses a lot of electricity for pumping and is very costly.
• In October 2023, piers (support pillars) of the Medigadda barrage sank. The National Dam Safety Authority (NDSA) held an inquiry, with a report in 2024. The current status should be checked against the latest NDSA report.

Tehri dam (Bhagirathi, Uttarakhand)

• River: the Bhagirathi rises at Gaumukh (Gangotri glacier). It meets the Alaknanda at Devprayag to form the Ganga.
• India's highest dam: 260.5 m, completed in 2005. It is built of earth, concrete and rockfill (TE/PG/ER). Uses: irrigation and hydel (NRLD 2018) [2].
• It lies in a seismic zone (an area prone to earthquakes). Sunderlal Bahuguna led protests against it.
• The geography of hydropower is covered in energy-resources-india.

10. Height ranking of key dams (from the CWC register, measured from the deepest foundation)

• Tehri 260.5 m > Bhakra 226 m > Sardar Sarovar 163 m > Pong 133 m > Nagarjuna Sagar 124.66 m > Hirakud 60.96 m [2]

Prelims Hooks

• Bhakra dam: Satluj river, Bilaspur (Himachal Pradesh), 1963, reservoir Gobind Sagar. Nangal dam is in Punjab. They serve Punjab, Haryana and Rajasthan.
• Hirakud: Mahanadi river, near Sambalpur, Odisha, 1957, earthen and among the world's longest. Trap: it is not on the Brahmani. Rengali is the dam on the Brahmani [2].
• DVC (7 July 1948): modelled on the Tennessee Valley Authority (USA). Tilaiya and Maithon are on the Barakar. Panchet is on the Damodar. The Damodar is the "river of sorrow" (of Bengal).
• Sardar Sarovar: Narmada river, Kevadia (Ekta Nagar), Gujarat, 138.68 m, completed 2017. It benefits Gujarat, MP, Maharashtra and Rajasthan. The Rajasthan districts served are Barmer and Jalore. Water sharing follows the NWDT award of 1979.
• Highest dam in India: Tehri (260.5 m) on the Bhagirathi. Second is Bhakra (226 m) [2].
• "Large dam" (ICOLD/CWC): more than 15 m high, or 10–15 m with extra conditions. "Dam of National Importance": 100 m or higher, or 1 km³ or more of storage [2].
• State with the most large dams: Maharashtra (2,354 of 5,701; NRLD 2018). Next are MP and Gujarat [2].
• Kaleshwaram is a lift scheme on the Godavari in Telangana (2019). The Medigadda barrage piers sank in Oct 2023.
• Nagarjuna Sagar is on the Krishna, not the Godavari. Sriramsagar is the one on the Godavari [2].
• "Temples of modern India" was Nehru's phrase for big dams.

Mains Points

• Why India built multipurpose projects (GS-I/III):
• Rain is seasonal and uneven, and big rivers flood (Damodar, Mahanadi).
• Big storage solved this: it controls floods, gives canal irrigation for the Green Revolution belt (Bhakra–Punjab, Haryana) and supplies hydel power for industry.

• This was Nehru's "temples of modern India" vision of linking villages with industry.

• Costs and criticism:

• Displacement and poor rehabilitation (Narmada Bachao Andolan).
• Reservoirs filling with silt.
• Forests and river ecosystems flooded.
• Waterlogging and salinity in canal areas.
• Interstate disputes (NWDT 1979).

• Seismic risk in the Himalaya (Tehri).

• Dam safety and ageing:

• Most of India's 5,264 large dams were built in 1971–90 [2]. Many are now old.
• The Medigadda barrage failure (2023) showed what poor design, poor quality control and poor operation can do.

• Policy response: the Dam Safety Act 2021 and the NDSA, which bring regular inspection and clear responsibility.

• The way forward:

• Use IWRM at the basin level.
• Prefer smaller, decentralised storage (check dams, rainwater harvesting) alongside big projects.
• Weigh the energy cost of lift schemes like Kaleshwaram against their irrigation gains.
• Make sure the people displaced also share in the project's benefits.