Multipurpose river project

Also called: Multipurpose project, Multipurpose river valley projects · Topic: Water Resources of India: Availability, Use and Conservation · NCERT: Class 10, Ch 3 "Water Resources"; Class 12, Ch 4 "Water Resources"

Meaning

A multipurpose river project is one project on a river, usually a dam, its reservoir and canals, that serves many uses at the same time: irrigation, hydropower, flood control, water supply, navigation, fish breeding and recreation.

• It matters because India's rain is seasonal. Water has to be stored in the wet months and used in the dry months.
• After independence these projects became the base of India's farm, power and flood-control planning. The Five Year Plans gave them high priority.

Explanation

How it works: cause → process → result

• Cause: seasonal and uneven rain
• Most of India's rain falls in the four monsoon months.

• Big rivers flood in the wet season and run low in the dry season. The Damodar and the Mahanadi are examples.

• Process: store the water, then share it out

• A dam (a wall built across flowing water) blocks the river's flow, turns it into a new direction or slows it down.
• Water collects behind the dam in a reservoir (an artificial lake).
• Extra water leaves safely over a spillway or weir (a low channel or wall that lets surplus water pass).

• Canals carry the stored water to fields and towns. Falling water turns turbines to make electricity.

• Result: one structure, many uses

• irrigation for crops
• hydropower (electricity from falling water)
• domestic and industrial water supply
• flood control downstream
• inland navigation
• pisciculture (fish breeding)

• recreation

• Example of coding: the CWC register gives Sardar Sarovar six purposes. They are Irrigation, Hydel, flood Control, water Supply, Navigation and Fisheries, written as "I/H/C/S/N&F" [2].

The idea behind it: "temples of modern India"

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

• India would leave behind its colonial past of poverty, famine and little industry.

• Planning frame: the projects were part of integrated water resources management (IWRM). IWRM means planning water for all the users of a river basin together.

• River valley authority model: the Damodar Valley Corporation (7 July 1948) was India's first multipurpose river valley authority. One body ran the dams, power, irrigation and flood control for a whole valley. It was modelled on the Tennessee Valley Authority (TVA) of the USA (1933).

Parts and types of dams used

• By structure and material:
• Timber
• Embankment (earth or rock fill)
• Masonry (stone or concrete)

• Hirakud is earth plus gravity. Bhakra is concrete gravity. Tehri is earth plus gravity plus rockfill [2].

• Gravity dam: a dam that holds water back by its own great weight. Bhakra and Sardar Sarovar are concrete gravity dams.

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

• A dam 10–15 m high also counts if it meets one of these conditions: 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].

• Dam of National Importance: 100 m or higher, or storing 1 km³ or more. India had 65 completed and 11 under construction in 2018 [2].

• Lift irrigation (newer type): water is pumped uphill in stages instead of flowing down by gravity.
• Barrages (low dams that raise the water level) collect the water.
• Pumps lift it to reservoirs higher up.
• Canals carry it to fields that sit above the river.

The other side: costs

• From the 1960s and 70s these projects faced criticism:
• Displacement: people lost homes and land, and rehabilitation was often poor. This led to the Narmada Bachao Andolan.
• Forests and river ecosystems went under water.
• Silt was trapped in reservoirs, so they filled up.
• Canal areas suffered waterlogging and salinity.
• Fights between states broke out over sharing water.
• Himalayan dams carry seismic risk (danger from earthquakes). Tehri is an example.

Where it occurs

• Bhakra-Nangal (Satluj):
• Bhakra dam is in Bilaspur district, Himachal Pradesh. It was completed in 1963. Its reservoir is Gobind Sagar.
• It is 226 m high and 518 m long, with a gross storage of 9.62 km³. Its uses are irrigation and hydel power [2].
• Nangal dam, a smaller dam downstream in Punjab, turns water into the canals.
• It serves Punjab, Haryana and Rajasthan.

• Linked works:

  • The Pong dam on the Beas (1974, 133 m) [2].
  • The Indira Gandhi Canal, which starts at the Harike barrage, where the Satluj and Beas meet. It carries water into the Thar desert.

• Hirakud (Mahanadi):

• It is near Sambalpur, Odisha, and was inaugurated in 1957. It is an earth plus gravity dam.
• It is 60.96 m high. The main dam is 4,800 m long. Its gross storage is 8.14 km³ and its reservoir covers 743 km² [2].
• Its uses are irrigation, hydel, flood control and water supply [2].

• With its long earthen dykes (side walls), it is among the world's longest earthen dams. It controls floods in the Mahanadi delta.

• Damodar Valley Corporation (Jharkhand–West Bengal):

• Tilaiya (on the Barakar) and Konar (on the Konar) were built in the 1950s.
• Maithon is on the Barakar (1957, 56 m) [2].
• Panchet is on the Damodar (1959, 48 m) [2].
• The register lists Maithon and Panchet in Jharkhand, with Asansol as the nearest city. They serve irrigation, hydel, water supply and flood control [2].

• The aim was to tame the Damodar, the "river of sorrow" of Bengal. DVC also runs thermal power stations that use coal from the valley.

• Nagarjuna Sagar (Krishna):

• It is on the Telangana–Andhra Pradesh border and was completed in 1974. It is an earth plus gravity dam.

• It is 124.66 m high, with a gross storage of 11.56 km³. Its uses are irrigation and hydel [2].

• Sardar Sarovar (Narmada):

• It is at Kevadia (Ekta Nagar), Narmada district, Gujarat. It is a concrete gravity dam.
• Its foundation stone was laid in 1961, and it was raised to its final height of 138.68 m in 2017.
• The register gives a height of 163 m from the deepest foundation, a length of 1,210 m and a gross storage of 9.50 km³ [2].
• Irrigation:
  • Gujarat: 18.45 lakh ha, about 75% of it drought-prone
  • Rajasthan: 2.46 lakh ha in Barmer and Jalore
  • Maharashtra: 37,500 ha in tribal hill areas, where water is lifted by pumps

• Madhya Pradesh also benefits. Water sharing follows the Narmada Water Disputes Tribunal award (1979).

• Tehri (Bhagirathi, Uttarakhand):

• It is India's highest dam at 260.5 m and was completed in 2005. Its uses are irrigation and hydel [2].

• It lies in a seismic zone. Sunderlal Bahuguna led protests against it.

• Kaleshwaram Lift Irrigation Project (Godavari, Telangana):

• It was 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.

• India's large dams overall (NRLD 2018):

• 5,264 completed and 437 under construction, a total of 5,701 [2].

• Maharashtra has the most (2,354), then Madhya Pradesh (906) and Gujarat (632) [2].

• World: the Tennessee Valley Authority (USA, 1933) is the model river valley authority.

Don't confuse with

• Single-purpose dam: it serves only one use, such as only irrigation. A multipurpose project serves several uses together from the same reservoir.
• Lift irrigation scheme (Kaleshwaram): it pumps water uphill using a lot of electricity. Classic multipurpose dams like Bhakra send water to fields by gravity, and they also produce hydel power.
• Barrage (Harike, Medigadda): a low dam that raises the water level to divert water into canals. It has no big storage reservoir like Gobind Sagar behind Bhakra.
• Large dam vs Dam of National Importance: a large dam is more than 15 m high (or 10–15 m with extra conditions). A Dam of National Importance is 100 m or higher, or stores 1 km³ or more [2].

Prelims Hooks

• Bhakra is on the Satluj in Bilaspur (Himachal Pradesh) and has the reservoir Gobind Sagar. Nangal is in Punjab.
• DVC (7 July 1948) was modelled on the TVA (USA). Tilaiya and Maithon are on the Barakar. Panchet is on the Damodar.
• Hirakud is on the Mahanadi, near Sambalpur (Odisha). Trap: it is not on the Brahmani. Rengali is the dam on the Brahmani [2].
• Nagarjuna Sagar is on the Krishna, not the Godavari. Sriramsagar is the dam on the Godavari [2].
• Height order (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].
• "Temples of modern India" was Nehru's phrase. The Rajasthan districts served by Sardar Sarovar are Barmer and Jalore.

Mains Points

• Why India built them (GS-I/III):
• Rain is seasonal and uneven, and rivers like the Damodar and Mahanadi flood.

• Big storage controlled floods and gave canal water to the Green Revolution belt (Bhakra in Punjab and Haryana). It also gave hydel power to industry, which was Nehru's plan to link villages with industry.

• Costs and dam safety (GS-III):

• Human and environmental costs: displacement (Narmada Bachao Andolan), reservoirs filling with silt, flooded forests, waterlogging and salinity, and interstate disputes (NWDT 1979). Tehri carries seismic risk.
• Ageing dams: most of India's 5,264 large dams were built in 1971–90, so many are now old [2].
• Medigadda warning: the barrage's piers sank in October 2023, which showed the danger of poor design, quality control and operation.

• Response: the Dam Safety Act 2021 and the National Dam Safety Authority (NDSA) bring regular inspection and clear responsibility.

• The way forward:

• Plan water by river basin using IWRM.
• Build smaller, local storage (check dams, rainwater harvesting) alongside big projects.
• Weigh the electricity cost of lift schemes like Kaleshwaram against what they add to irrigation.
• Make sure displaced people also share in the project's benefits.

Related concepts

• Temples of modern India
• Bhakra-Nangal project
• Hirakud dam
• Damodar Valley Corporation
• Sardar Sarovar project
• Kaleshwaram lift irrigation project

Read more

• Multipurpose river projects: the "temples of modern India"