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Kaveri
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| Kaveri Cauvery | |
|---|---|
|
Clockwise from top left: Talakaveri; Kaveri at Srirangapatna; Hogenakkal Falls; Kallanai Dam; Confluence with Bhavani; and Shivanasamudra Falls | |
Kaveri River basin | |
| Location | |
| Country | India |
| Region | South India |
| States | Karnataka, Tamil Nadu, Kerala, Puducherry |
| Physical characteristics | |
| Source | Western Ghats |
| • location | Talakaveri, Kodagu district, (Coorg) Karnataka |
| • coordinates | 12°23′N 75°29′E / 12.383°N 75.483°E |
| • elevation | 1,341 m (4,400 ft) |
| Mouth | Bay of Bengal |
• location | Poompuhar, Mayiladuthurai district, Tamil Nadu |
• elevation | 0 m (0 ft) |
| Length | 800 km (500 mi)[1] |
| Basin size | 81,155 km2 (31,334 sq mi)[2] |
| Discharge | |
| • location | Lower Anaicut (58.5 km upstream of mouth) |
| • average | 919 m3/s (32,500 cu ft/s) (1998-2024)[3] |
| • minimum | 144 m3/s (5,100 cu ft/s)[3] |
| • maximum | 4,075 m3/s (143,900 cu ft/s)[3] |
| Discharge | |
| • location | Grand Anicut (140 km upstream of mouth) |
| • average | 400.716 m3/s (14,151.2 cu ft/s) (1976-1979)[5] 1,131 m3/s (39,900 cu ft/s) (1998-2024)[4] |
| • minimum | 78 m3/s (2,800 cu ft/s)[4] |
| • maximum | 4,916 m3/s (173,600 cu ft/s)[4] |
| Basin features | |
| Tributaries | |
| • left | Harangi, Hemavati, Shimsha, Arkavati, Sarabanga, Thirumanimutharu |
| • right | Lakshmana Tirtha, Kabini, Bhavani, Noyyal, Amaravati, Moyar |
The Kaveri (also known as Cauvery, Tamil: [kɑːʋɪɾi]) is a major river flowing across Southern India. It is the third largest river in the region after Godavari and Krishna. The catchment area of the Kaveri basin is estimated to be 81,155 km2 (31,334 sq mi) and encompasses the states of Tamil Nadu, Karnataka, Kerala, and the union territory of Puducherry.
The river rises at Talakaveri in the Brahmagiri range in the Western Ghats. The source is located at an elevation of 1,341 m (4,400 ft) in the Kodagu district of Karnataka. The river flows for about 320 km (200 mi) through the Deccan plateau in Karnataka before entering Tamil Nadu. It flows further eastward in Tamil Nadu for 416 km (258 mi) before flowing into the Bay of Bengal near Poompuhar in Mayiladuthurai district of Tamil Nadu. The river flows for a total length of about 800 km (500 mi). The major tributaries include Amaravati, Arkavati, Bhavani, Harangi, Hemavati, Kabini, Lakshmana Tirtha, Shimsha and Noyyal.
There are a number of dams on the river which form part of an extensive irrigation system and are used for the generation of hydroelectric power. The river has supported agriculture for centuries and has served as the lifeline of several kingdoms in the past. Access to the river's waters has been a cause of dispute among the states of Karnataka and Tamil Nadu for decades. The Kaveri basin is a densely populated region, with several towns and cities located on its banks.
The river is considered as sacred by the people of Southern India and is considered to be among the seven holy rivers of India. The river is often personified and worshiped as the goddess Kaveri. The river is mentioned in various Hindu religious texts including the Mahabharata and the Puranas. In ancient Tamil literature, the river is referenced to as Ponni meaning "the golden one".
Etymology
[edit]Kaveri is mentioned in Sanskrit as a holy river in various Hindu religious texts including the Mahabharata and the Puranas.[6] The name itself might have had different etymologies. As per Skanda Purana, the river arose after Ganesha took a form of a crow and toppled sage Agastya's kamandala. The river then took its name from the Tamil language words kā meaning "crow" and viri meaning "spread" literally translating to "spread by a crow". It might also mean a river with wide spread banks as viri can also be translated as wide spread.[6][7][8] The etymology of the river might have also been derived from kāviri, the Sankethi word for "river" from the language spoken by the Sankethi people, who live along its waters.[9] Cauvery is the anglicized version of the original name.[8]
The river is also known by other names. In ancient Tamil literature, the river was called Ponni meaning "the golden one" in reference to the fine silt it deposits.[10][11][12] It is known as Daksina gaṅgā meaning the "Ganges of the South" indicating its geographical location and its significance.[13] It is also mentioned as Ardha gaṅgā meaning Half Ganga in Mahabharata and other literature, due to its purported mythology of having arisen from the Ganges.[6] Marudvṛdhā is another hypothesised name for this river, meaning "the beloved of the Maruts" in Sanskrit.[14]
Course
[edit]The river arises at Talakaveri in Kodagu district of Karnataka.[15] The source of the river is located at an altitude of 1,341 m (4,400 ft) in the Brahmagiri Hills of the Western Ghats.[1] Its follows a rough upper course consisting of rocky beds and high banks. Once it leaves the Kodagu hills, it flows eastwards and forms a series of rapids and falls. It flows through a narrow gorge onto the Deccan plateau and drops about 18–24 m (59–79 ft) at Chunchanakatte Falls.[13] The river forms the island of Srirangapatna and widens to 900–1,200 ft (270–370 m) before flowing south-east.[13][15] At Shivanasamudra, the river drops 91 m (299 ft) and forms the Shivanasamudra Falls, one of the largest waterfalls in the country.[1][15] After forming the island of Shivanasamudra, the river converges and passes through the Mekedatu gorge.[1][16] After flowing for 320 km (200 mi) in Karnataka, the river flows for about 64 km (40 mi) along the Karnataka-Tamil Nadu border.[1]
The river enters Tamil Nadu and forms the Hogenakkal Falls.[15] After the falls, the river flows southwards towards Mettur Dam and joins its main right bank tributary Bhavani at Kooduthurai.[1][16] The river flows eastwards through Erode and Karur, and widens further before entering the Tiruchirappalli district. It splits into two branches with the northern part called as Kollidam River and the southern part of the river retaining the name Kaveri.[1] After flowing for 16 km (9.9 mi), the two branches converge around the Srirangam island.[1][16] The river further branches off into 36 different channels before emptying into the Bay of Bengal near Poompuhar in Mayiladuthurai district.[17] The river traverses for about 416 km (258 mi) in Tamil Nadu for a total length of about 800 km (500 mi).[1]
Tributaries
[edit]The Kaveri River has 21 major tributaries.[1] The largest tributary Hemavati, and Lakshmana Tirtha join the river at Krishna Raja Sagara.[1][13] Kabini is another major contributor to the flow of Kaveri and joins the river in Karnataka. It meets with its second largest tributary Bhavani at Kooduthurai in Bhavani and two other tributaries Noyyal, and Amaravati join further down the stream in Tamil Nadu.[1] Other tributaries of Kaveri include Shimsha, Arkavati, Sarabanga, and Thirumanimutharu.[1][16]
Discharge
[edit]| Year | Grand Anicut | Lower Anicut | ||||||
|---|---|---|---|---|---|---|---|---|
| (m3/s) | (m3/s) | |||||||
| Min | Mean | Max | Min | Mean | Max | |||
| 1998 | 170 | 1,099 | 3,454 | 161 | 885 | 2,540 | ||
| 1999 | 289 | 1,131 | 3,778 | 285 | 864 | 2,845 | ||
| 2000 | 343 | 1,287 | 4,903 | 233 | 1,011 | 3,335 | ||
| 2001 | 258 | 1,080 | 3,348 | 309 | 948 | 3,115 | ||
| 2002 | 139 | 772 | 2,392 | 144 | 867 | 2,423 | ||
| 2003 | 78 | 667 | 2,297 | 216 | 646 | 2,100 | ||
| 2004 | 103 | 895 | 3,303 | 217 | 839 | 3,160 | ||
| 2005 | 179 | 1,012 | 3,354 | 240 | 991 | 3,873 | ||
| 2006 | 268 | 1,072 | 2,495 | 473 | 1,091 | 3,187 | ||
| 2007 | 118 | 993 | 3,308 | 324 | 1,126 | 4,075 | ||
| 2008 | 132 | 1,094 | 3,677 | 398 | 1,103 | 3,167 | ||
| 2009 | 227 | 1,040 | 3,238 | 290 | 965 | 3,301 | ||
| 2010 | 373 | 1,080 | 3,141 | 411 | 1,022 | 3,626 | ||
| 2011 | 171 | 1,163 | 3,815 | 296 | 928 | 3,014 | ||
| 2012 | 190 | 874 | 3,342 | 177 | 711 | 2,149 | ||
| 2013 | 82 | 1,043 | 3,281 | 229 | 856 | 3,127 | ||
| 2014 | 279 | 1,148 | 3,663 | 409 | 980 | 2,533 | ||
| 2015 | 559 | 1,422 | 3,816 | 407 | 913 | 2,177 | ||
| 2016 | 490 | 1,129 | 2,890 | 276 | 728 | 1,733 | ||
| 2017 | 216 | 931 | 3,586 | 154 | 671 | 1,832 | ||
| 2018 | 341 | 1,571 | 4,439 | 266 | 934 | 3,427 | ||
| 2019 | 331 | 1,473 | 4,559 | 173 | 966 | 3,070 | ||
| 2020 | 591 | 1,590 | 4,373 | 209 | 983 | 2,944 | ||
| 2021 | 478 | 1,502 | 3,935 | 257 | 988 | 3,136 | ||
| 2022 | 548 | 1,713 | 4,916 | 407 | 1,172 | 3,385 | ||
| Overall | 78 | 1,151 | 4,916 | 144 | 928 | 4,075 | ||
Geology and ecology
[edit]
The Kaveri basin was formed in the Late Jurassic to Early Cretaceous period during Gondwana breakup and opening of the Indian Ocean.[18] Most of the basin is made up of Precambrian rocks and the two major rock types that are found are metamorphic and igneous rocks.[16] Closepet granite is found in the upper parts of the Kaveri basin and Charnockite rocks are only found in the central part.[15] A 2017 paper proposed that an impact structure was present in the vicinity of the Kaveri river.[19] The run-off from the river does not drain off quickly because of the shape of the river basin, which limits the occurrence of floods. It is a perennial river fed mostly by monsoons. Four distinct seasons occur in the basin with hot and cold seasons sandwiching the monsoon seasons. The river basin is fed by South-West monsoon in Karnataka, and North-East monsoon in Tamil Nadu.[1]
The Kaveri basin is made up of two sub-zones, forest and agro-ecosystem.[20] The forest vegetation consists of a mix of dry deciduous, evergreen forests, and grasslands.[21] As per a study, about 12,850 km2 (4,960 sq mi) of natural vegetation was lost in the river basin between 1965 and 2016.[22] The basin has a variety of flora with major species including Terminalia arjuna, Tamarindus indica, Pongamia pinnata, Salix tetrasperma, Ficus benghalensis, Ficus religiosa, Eucalyptus torticornis, and Diospyros montana.[20]
There are many protected areas spread across the river basin including significant tiger and elephant habitats. The basin provides habitat to a range of animal species such as gaur, leopard, sloth bear, Bengal tiger, Indian elephant, Nilgiri tahr, grizzled giant squirrel, and various species of deer, wild boar and reptiles.[21] The river also hosts a variety of avifauna including the painted stork (Mycteria leucocephala), spot-billed pelican (Pelecanus philippensis), and black-headed ibis (Threskiornis melanocephalus). It is also home to the mugger crocodile (Crocodylus palustris), smooth-coated otter (Lutrogale perspicillata), and hump-backed mahseer (Tor remadevii).[23]
Riparian zone
[edit]
The total watershed of the basin is 81,155 km2 (31,334 sq mi) and the riparian zone of the river consists of 43,856 km2 (16,933 sq mi) in Tamil Nadu, 34,273 km2 (13,233 sq mi) in Karnataka, 2,866 km2 (1,107 sq mi) in Kerala, and 160 km2 (62 sq mi) in the union territory of Puducherry.[2][1] Over half of the Kaveri basin is arable and the most cultivated crops are rice and sugarcane.[20] An estimate at the time of the first Five Year Plan put the total flow of the river at 15 cubic kilometres (12,000,000 acre⋅ft), of which 60% was used for irrigation.[24] The river is also used for drinking water and hydroelectric power generation.[13][25]
The Grand Anicut was constructed by a Chola King in 2nd century CE.[1] The hydroelectric plant built on the Sivanasamudra Falls in 1902 was the first hydroelectric plant in Asia.[26] The Mettur Dam in Tamil Nadu was constructed in 1934 and the Stanley Reservoir formed by the dam has a capacity of 93.4 tmc ft.[13][27] Krishna Raja Sagara in Karnataka is the second largest dam on the river and has a capacity of 49.5 tmc ft.[27][28] Bhavanisagar Dam (32.8 tmc ft) on the Bhavani River in Tamil Nadu, Gorur dam (37.1 tmc ft) on the Hemavathi River, Kabini Dam (18.5 tmc ft) on the Kabini River, and Harangi Dam (9.5 tmc ft) on the Harangi River in Karnataka are major dams on the tributaries of Kaveri.[2][27]
Water dispute
[edit]
The dispute over the sharing of Kaveri waters began in 1807 when the Madras Presidency objected to the plans of the Mysore kingdom to develop irrigation projects. After initial discussions failed, the British Raj intervened and a six rule agreement called the General Agreement of 1892 was signed.[29] After Indian Independence, article 262 of the Constitution of India provided powers to the Government of India to adjudicate on inter-state disputes on water sharing.[30] The Government of India constituted the Cauvery Water Disputes Tribunal (CWDT) on 2 June 1990 to adjudicate the water dispute between the riparian states and territories in the river basin. In an order passed in June 1991, the CWDT directed Karnataka to release 205 tmc ft of water per year to Tamil Nadu based on a specific schedule. The water was to be released in four equal installments in a particular month and any shortfall would need to be covered in the subsequent week. Tamil Nadu was directed to provide 6 tmc ft of water to Puducherry.[2]
In July 1991, the President of India asked the Supreme Court of India to rule on the validity and legality of the tribunal under the Constitution. In November 1991, the Supreme Court opined that the order needs to be published by the central government in the Official Gazette, which was done on 1 December 1991.[2] In May 1992, the Government of Tamil Nadu filed a case in the Supreme Court to direct the Indian Government to pass necessary orders to ensure the implementation of the provisions of the tribunal order. In April 1997, the Attorney General of India reverted that the central government has prepared a scheme under the Inter-State Water Disputes Act, 1956 for the implementation of the tribunal award and the Cauvery Water Authority (CRA) and Cauvery Monitoring Committee (CMC) were formed subsequently as a part of the Cauvery Water (Implementation of Interim Orders of 1991 and all subsequent Tribunal Orders) Scheme, 1998. The CRA is headed by the Prime Minister of India and consists of the Chief Ministers of the riparian states as its constituent members.[2]
On 16 February 2018, the Supreme Court ruled that Karnataka will get 284.75 tmc ft, Tamil Nadu will get 404.25 tmc ft, Kerala will get 30 tmc ft and Puducherry will get 7 tmc ft of water from the river. An additional 10 tmc ft was reserved for environmental protection and 4 tmc ft was reserved for wastage into the sea.[31] The court directed the government to form a Cauvery Water Management Authority (CWMA) within six weeks and acting on the Supreme Court's direction, the central government constituted the CMWA in June 2018.[32][33][34]
Religious significance
[edit]
In Hinduism, the river is considered one of seven holy rivers in India. The river is personified and worshiped as the river goddess Kaveri Amma.[6][35] Kaveri is mentioned as both a river and a goddess in various Hindu texts such as the Mahabharata and the Puranas. The river is mentioned as one of the seven holy Gangas and bathing in the river is said to grant one's desired as per the Sivapurana. The Varaha Purana states that the river flows from the five great mountains and gives longevity to those who drink the waters of the river. The Skanda Purana narrates the various origins of the river. Shiva filled Agastya's bowl with Kaveri, who flowed as a river with the help of Ganesha.[6]
In another legend, Lopamudra becomes Agastya's wife and takes on a form of water during a severe drought in South India. Agastya carries her in his small brass water pot and Ganesha, in the form of crow, knocks the water pot down. The spilled water runs down the hill and onto the drought-stricken land.[36] Another story narrates that during the Samudra Manthana, or churning of the Ocean of Milk, Mohini and Lopamudra retrieved the nectar of immortality for the gods. Afterwards, Brahma took care of Lopamudra as his daughter and later offered her to king Kavera, who renamed her as Kaveri. When Kaveri grew up she prayed to Brahma to transform her into a purifying river.[35]
As per the Tamil literature Manimekalai, Agastya drank the Ganges River in anger, when the floods destroyed his tapas and later released it in South India. Silapathikaram mentions Kaveri as the daughter of Kavera. In Theravada Buddhism, Kaveri is mentioned as a water channel. It is part of the twenty canal-systems associated with the reservoir Parakkamasamudda that existed in the Polonnaruwa region during the reign of king Parakramabahu I.[6]
Kaveri Pushkaram is a Hindu festival dedicated to the river.[37] It is generally observed once every 12 years,[37] with a "Maha Pushkaram" held every 144 years.[38][39] The key pilgrimage sites includes Srirangam and Thula Kattam at Mayiladuthurai near the mouth of the river.[38][39] The festival is celebrated for 12 days, and includes ceremonial observations such as homam, yagnam, chanting of the Vedas, ritual feeding, and tharpanam accompanied by cultural activities such as music, dance, and spiritual speeches.[39]
See also
[edit]References
[edit]- ^ a b c d e f g h i j k l m n o p Integrated Hydrological Data Book (PDF) (Report). Central Water Commission. p. 92. Archived from the original (PDF) on 2 April 2016. Retrieved 13 November 2017.
- ^ a b c d e f "Cauvery Water". Ministry of Jal Shakti, Government of India. Retrieved 1 June 2024.
- ^ a b c d "River Discharge and Reservoir Storage Changes - Area 2043". Flood observatory, Colorado University. Retrieved 1 June 2024.
- ^ a b c d "River Discharge and Reservoir Storage Changes - Area 2042". Flood observatory, Colorado University. Retrieved 1 June 2024.
- ^ "Gauging Station - Data Summary". RivDis. Archived from the original on 4 October 2013. Retrieved 1 October 2013.
- ^ a b c d e f "Kaveri". Wisdom library. Retrieved 1 June 2024.
- ^ "River Kaveri Story". Samayam (in Tamil). 9 September 2021. Retrieved 1 June 2024.
- ^ a b "Cauvery flows, thanks to a crow!". E-pao. 4 January 2024. Retrieved 1 June 2024.
- ^ "How the Rivers of India Descended From the Heavens: Kaveri". Outlook. 5 November 2022. Retrieved 1 June 2024.
- ^ "Daughter of Ponni". The Indian Express. 27 April 2014. Retrieved 27 April 2014.
- ^ "Cauvery Chronicles II: Ponni's Perish". Newslaundry. 8 February 2020. Retrieved 8 February 2020.
- ^ "The death of a river". Millennium Post. 11 June 2019. Retrieved 11 June 2019.
- ^ a b c d e f "Kaveri River". Britannica. Retrieved 1 June 2024.
- ^ "Marudvṛdhā". Sanskrit Lexicon. Retrieved 18 July 2022.
- ^ a b c d e Jain, Sharad K.; Agarwal, Pushpendra K.; Singh, Vijay P. (2007). Hydrology and Water Resources of India. Springer Science. pp. 702–711. ISBN 9781402051807.
- ^ a b c d e Singh, Dhruv Sen (2018). The Indian rivers : scientific and socio-economic aspects. Singapore: Springer Science. pp. 354–356.
- ^ Ramkumar, Mu; Kumaraswamy, K.; Mohanraj, R. (2015). Environmental Management of River Basin Ecosystems. Springer Science. p. 286. ISBN 978-3-319-13425-3.
- ^ Nagendra, R.; Nallapa Reddy, A. (2017). "Major geologic events of the Cauvery Basin, India and their correlation with global signatures – A review". Journal of Palaeogeography. 6 (1): 69–83. Bibcode:2017JPalG...6...69N. doi:10.1016/j.jop.2016.09.002.
- ^ Subrahmanya, K. R.; Prakash Narasimha, K. N. (October 2017). "Kaveri crater – An impact structure in the Precambrian terrain of southern India". Journal of the Geological Society of India. 90 (4): 387–395. Bibcode:2017JGSI...90..387S. doi:10.1007/s12594-017-0733-5. ISSN 0016-7622. S2CID 134717819.
- ^ a b c Sunil, C.; Somashekar, R. K.; Nagaraja, B. C. (1 November 2010). "Riparian vegetation assessment of Cauvery River Basin of South India". Environmental Monitoring and Assessment. 170 (1): 548. Bibcode:2010EMnAs.170..545S. doi:10.1007/s10661-009-1256-3. PMID 20024615. S2CID 19865294.
- ^ a b National Parks and Wildlife Sanctuaries in India (PDF). Ministry of Environment, Forest and Climate Change, Government of India (Report). November 2021. Retrieved 1 June 2024.
- ^ "Natural vegetation on nearly 12,850 sq. km in the Cauvery basin has been lost, says a research paper". The Hindu. 11 December 2023. Retrieved 1 June 2024.
- ^ "Ranganathittu Bird Sanctuary". Ramsar Sites Information Service. Retrieved 18 February 2023.
- ^ "Chapter 26: Irrigation and power". 1st Five Year Plan. Planning Commission of India. Archived from the original on 28 March 2019. Retrieved 1 July 2019.
- ^ "Archived copy" (PDF). TCE. Archived from the original (PDF) on 20 March 2007. Retrieved 13 January 2022.
{{cite web}}: CS1 maint: archived copy as title (link) - ^ "World Waterfall Database". Archived from the original on 14 November 2006. Retrieved 9 November 2006.
- ^ a b c "Reservoir levels". Government of Tamil Nadu. Retrieved 1 June 2024.
- ^ "Corporation urged to chalk out water policy for Mysore city". The Hindu. 26 March 2006. Archived from the original on 29 October 2006.
- ^ Rani, Midatala; Rani, Middatala (2002). "Historical Background Of The Cauvery Water Dispute". Proceedings of the Indian History Congress. 63: 1033–1042. JSTOR 44158173.
- ^ "Article 262 of Indian Constitution". Indiakanoon. Retrieved 1 June 2024.
- ^ "Archived copy" (PDF). Archived from the original (PDF) on 17 April 2018. Retrieved 24 July 2018.
{{cite web}}: CS1 maint: archived copy as title (link) - ^ Rajagopal, Krishnadas (16 February 2018). "Supreme Court curtails Tamil Nadu's share of Cauvery water". The Hindu. ISSN 0971-751X. Retrieved 1 June 2020.
- ^ "Cauvery Water Management Scheme, 2018". Ministry of Jal Shakti, Government of India. Retrieved 1 June 2024.
- ^ "Cauvery dispute". News Minute. 23 June 2018. Retrieved 1 June 2020.
- ^ a b Warrier, Shrikala (2014). Kamandalu: The Seven Sacred Rivers of Hinduism. Mayur University. pp. 20, 192–195. ISBN 978-0-95356-797-3.
- ^ Eck, Diana L. (2012). India: A Sacred Geography. United States: Harmony Books. p. 179. ISBN 978-0-385-53191-7.
- ^ a b "Cauvery Pushkaram: Celebration of rivers". The Indian Express. 19 September 2019. Retrieved 1 June 2024.
- ^ a b "Kaveri Maha Pushkaram 2017 Celebration in Srirangam and Mayiladuthurai: Tamil Nadu Set for Holy Festival along Cauvery". India.com. 12 September 2017. Retrieved 1 June 2024.
- ^ a b c "Mayiladuthurai ready for Cauvery Maha Pushkaram". The Hindu. 11 September 2017. Retrieved 1 June 2024.
External links
[edit]Kaveri
View on GrokipediaLinguistic and Cultural Origins
Etymology and Historical Names
The name Kaveri (also spelled Cauvery in anglicized form) originates from the Sankethi dialect term meaning "one who brings abundance where she flows," reflecting the river's role in irrigating fertile lands across southern India.[9] This etymology aligns with Tamil linguistic interpretations, where Ka-Viri denotes "the river with a mighty spread," emphasizing its expansive delta and agricultural productivity.[10] In ancient Sanskrit texts such as Puranas, the river appears as Kāverī, listed among sacred waterways emerging from mountains like Śailavarṇa, underscoring its mythological status as a life-giving entity.[11] Historically, the river has borne regional names tied to cultural reverence. In classical Tamil literature, including Sangam-era works, it is known as Ponni ("the golden one"), derived from the fine golden silt deposited in its delta, which enhanced soil fertility for rice cultivation.[5] This designation persists in Tamil traditions, symbolizing prosperity, while broader Indian nomenclature refers to it as the "Dakshin Ganga" or "Ganga of the South," highlighting its sanctity comparable to the Ganges in Hindu cosmology, with origins traced to Vedic and post-Vedic hymns invoking river deities.[12] Spelling variations—Kaveri predominant in Kannada contexts and Cauvery in Tamil and English—stem from phonetic adaptations across Dravidian languages, without altering the core semantic roots.[11]Physical Geography
Course and Basin Overview
The Kaveri River originates at Talakaveri on the Brahmagiri Range in the Western Ghats of Kodagu district, Karnataka, at an elevation of 1,341 meters above sea level. From its source, the river flows southeasterly through hilly, forested terrain in the initial stretch, gradually descending across the Deccan Plateau. It traverses approximately 320 kilometers within Karnataka, passing through districts including Kodagu, Mysuru, Mandya, and Chamarajanagar, where it forms notable features such as the Shivanasamudra Falls before entering Tamil Nadu near the border town of Srirangapatna.[13][14] In Tamil Nadu, the river continues for about 416 kilometers eastward, flowing through the districts of Salem, Erode, Tiruchirappalli, Karur, Thanjavur, and Nagapattinam. It supports major urban centers including Tiruchirappalli (Trichy) and Thanjavur, before widening into a fertile delta region covering roughly 11,000 square kilometers. The river ultimately discharges into the Bay of Bengal through multiple distributaries near Poompuhar, with a total course length estimated at 800 kilometers.[14][12][15] The Kaveri basin encompasses a drainage area of 81,155 square kilometers, distributed across Karnataka (approximately 42%), Tamil Nadu (41%), Kerala (1%), and the Union Territory of Puducherry, with minor contributions from Andhra Pradesh. Bounded by the Western Ghats to the west, the Eastern Ghats and Bay of Bengal to the east, and the Nilgiri Hills to the north, the basin features a mix of upland plateaus, lowlands, and coastal plains, predominantly underlain by Archaean crystalline rocks that influence its hydrological regime through limited aquifer recharge and high runoff during monsoons.[13][15]Tributaries and Sub-Basins
The Kaveri River is augmented by several major tributaries, which contribute significantly to its flow and define key sub-basins within its 81,155 km² drainage area spanning Karnataka, Tamil Nadu, Kerala, and Puducherry.[16] These tributaries originate primarily from the Western Ghats and join the main stem along its course, with left-bank tributaries dominating the upper reaches in Karnataka and right-bank ones adding volume further downstream.[3] Key left-bank tributaries include the Harangi, which joins near Kushalnagar in Kodagu district, Karnataka; the Hemavati, confluent at the Krishna Raja Sagara reservoir; the Shimsha; and the Arkavati.[3][17] Right-bank tributaries in the upper basin comprise the Lakshmanatirtha, also joining at Krishna Raja Sagara, the Kabini at Tirumakudalu Narasipura, and the Suvarnavathi.[16][3] In the middle and lower reaches through Tamil Nadu, prominent right-bank tributaries are the Bhavani, joining approximately 45 km below Mettur Reservoir; the Noyyal; and the Amaravati.[12][13] The Cauvery basin is administratively divided into three primary sub-basins: the Upper Cauvery (upstream of Mettur), Middle Cauvery, and Lower Cauvery (including the delta), encompassing 132 watersheds in total.[13] These sub-basins correspond roughly to hydrological zones where tributary inflows dominate: the upper sub-basin receives contributions from Harangi, Hemavati, Kabini, and others, forming the core Karnataka catchment; the middle features Bhavani and associated flows; and the lower extends to the deltaic distributaries like Coleroon and Vennar.[13] Finer delineations identify up to 11 tributary-led sub-basins, such as those of the Kabini, Bhavani, and Amaravati, each with distinct catchment characteristics influencing local hydrology and water allocation.[18]| Major Tributary | Bank | Confluence Location | Notes |
|---|---|---|---|
| Harangi | Left | Near Kushalnagar, Karnataka | Originates in Western Ghats, Kodagu district.[17] |
| Hemavati | Left | Krishna Raja Sagara reservoir | Key contributor to upper basin flow.[16] |
| Kabini | Right | Tirumakudalu Narasipura, Karnataka | Formed by Panamaram and Mananthavady rivers in Kerala.[19] |
| Bhavani | Right | ~45 km below Mettur, Tamil Nadu | Major inflow in middle basin.[12] |
| Amaravati | Right | Near Karur, Tamil Nadu | Longest tributary in Tamil Nadu segments.[20] |
Discharge Patterns and Hydrology
The hydrology of the Kaveri River basin is predominantly driven by monsoon precipitation, with an average annual rainfall of 1075 mm across the basin, where the southwest monsoon (June to September) contributes the majority in the upper catchment in Karnataka, while the northeast monsoon (October to December) provides significant input to the lower reaches in Tamil Nadu.[21] [22] This seasonal rainfall pattern results in highly variable runoff, with surface flows dominating during monsoons due to intense precipitation events, and baseflow sustaining drier periods through groundwater contributions estimated at approximately 57% of total flow pre-monsoon and 42% during the southwest monsoon.[23] Discharge patterns exhibit strong seasonality, with peak flows occurring from July to October, accounting for over 75% of annual discharge, while non-monsoon flows typically constitute less than 25% of the total.[24] The mean discharge, based on observations from 1998 to 2021, averages 919 cubic meters per second, reflecting the basin's overall water yield influenced by its 81,155 square kilometer area and runoff dynamics.[25] At specific gauging stations like Lower Anicut, historical averages have reached around 928 cubic meters per second, though flows diminish downstream due to diversions and evaporation.[26] High variability is evident in the coefficient of variation for annual discharges, underscoring the river's susceptibility to inter-annual fluctuations tied to monsoon intensity.[27] Extreme flood events punctuate the regime, driven by short-duration intense rainfall, with recorded peaks such as 7,690 cubic meters per second at Musiri in 2005, as documented by the Central Water Commission.[28] Hydrological observations, including gauge levels and discharge measurements at multiple stations, reveal that runoff does not drain rapidly from the basin's topography, mitigating some rapid flood rises but still enabling significant inundation during heavy monsoon downpours.[16] Recent analyses indicate upward trends in extreme rainfall events, potentially amplifying future discharge variability amid climate shifts.[29]Geology and Ecology
Geological Formation and Soil Characteristics
The Kaveri River basin, encompassing approximately 81,155 square kilometers across Karnataka, Tamil Nadu, Kerala, and Puducherry, originated through rift tectonics linked to the Late Jurassic–Early Cretaceous breakup of Gondwana, initiating a taphrogenic rift process that separated the Indian plate from Antarctica and Australia.[30] This rifting produced an extensional regime between India and Sri Lanka, forming a fault-controlled depression with structural highs and lows, overlain by Cretaceous sedimentary sequences up to several thousand meters thick in offshore extensions.[31] The basement geology predominantly comprises Precambrian cratonic rocks of Archaean–Proterozoic age, including granitic gneisses, charnockites, Dharwar supergroup schists, and peninsular gneisses exposed along the western margins in the Western Ghats.[32] [33] Sedimentary infill includes fluvio-deltaic and marine deposits from the Cretaceous Uttatur and Ariyalur Groups, with shale, sandstone, and limestone formations reflecting episodic transgressions and regressions influenced by eustatic sea-level changes and tectonic subsidence.[34] Shear zones, such as the east-west trending Cauvery Shear Zone, dissect the Precambrian basement, influencing fault patterns and hydrocarbon traps in sub-basins like Krishna-Godavari extensions, though onshore portions show limited volcanic influence from the Deccan Traps due to the basin's southern position.[35] These ancient crystalline rocks weather into nutrient-poor substrates, contributing to the basin's moderate seismic stability despite historical rift reactivation. Soil profiles vary by physiographic zone, with red soils (alfisols and ultisols) dominating upland areas on weathered Precambrian bedrock, characterized by low fertility, high iron oxide content, and moderate erosion potential due to their sandy loam texture and acidity (pH 5.5–6.5).[2] Black soils (vertisols), derived from basaltic influences in transitional zones, exhibit high clay content (over 40%), swelling-shrinkage properties, and superior water retention, supporting rainfed crops like cotton and pulses across about 20% of the basin.[2] Lateritic soils cap hilltops in the Western Ghats, featuring gravelly, phosphorus-deficient layers with poor drainage, while alluvial soils in the lower reaches and delta—comprising fine silts and clays from gneissic sources—offer high fertility (organic carbon 0.5–1.0%) and form the basis for intensive rice paddy systems, though susceptible to salinization from over-irrigation.[36] Forest and mixed soils in riparian zones blend humus-rich loams with sandy variants, aiding biodiversity but facing degradation from deforestation rates exceeding 1% annually in some sub-basins.[37] These characteristics reflect parent material from charnockitic and granitic provenance, with floodplain sediments showing quartz-feldspar dominance and clay minerals like kaolinite, limiting permeability in clay-rich deltas (infiltration rates <10 mm/hour).[38]Biodiversity and Riparian Ecosystems
The riparian ecosystems of the Kaveri River, spanning from the moist deciduous forests of the Western Ghats to dry deciduous and scrub zones in the downstream plains, feature specialized vegetation adapted to seasonal inundation and fluctuating water levels, including gallery forests with deep-rooted trees that stabilize banks and regulate microclimates. These zones exhibit varying structural complexity, with less-disturbed upstream stretches supporting higher tree densities and basal areas dominated by native species such as Terminalia arjuna and Syzygium cumini, while downstream and disturbed areas show shifts toward invasive exotics like Acacia nilotica.[39] Overall, riparian forests in the basin harbor at least 73 tree species across surveyed sites in the Cauvery Wildlife Sanctuary, with Shannon-Wiener diversity indices ranging from 2.7 in high-disturbance zones to 3.2 in intact areas, reflecting gradient-based richness influenced by elevation and hydrology.[39] [40] Aquatic biodiversity is particularly pronounced in upstream tributaries and sanctuaries, where the river's heterogeneous habitats—pools, riffles, and cascades—sustain 58 fish species across 18 families and 44 genera, approximately 25% of which are endemic to the Western Ghats and 8 species unique to the Kaveri system, including the critically endangered Tor remadevii (hump-backed mahseer) and Hemibagrus punctatus.[41] These ichthyofaunal assemblages underscore the basin's role within the Western Ghats biodiversity hotspot, supporting migratory and resident populations vital for trophic dynamics, though endemic taxa face pressures from habitat fragmentation. Terrestrial fauna in riparian corridors includes 22 large mammal species, such as otters utilizing riverine dens for breeding, alongside big cats and herbivores that traverse these linear habitats as corridors.[42] [43] Avian and reptilian components further enrich these ecosystems, with riparian zones hosting around 41 bird species that exploit foraging opportunities along the riverine edge, including water-dependent taxa, and 10 reptile species adapted to semi-aquatic interfaces.[42] The Cauvery Wildlife Sanctuary exemplifies these hotspots, encompassing deciduous and riparian forests that integrate floral diversity with faunal refugia, fostering ecosystem services like pollination and nutrient cycling essential to adjacent agro-landscapes.[41] Conservation of these interfaces is critical, as intact riparian buffers maintain species persistence amid basin-wide hydrological variability.[44]Environmental Degradation Factors
The Cauvery River basin faces multifaceted environmental degradation driven by pollution, land use alterations, and extractive activities, which have compromised water quality, increased sedimentation, and diminished ecological integrity. Industrial effluents laden with heavy metals and chemicals from urban-industrial hubs like Bengaluru, Mysuru, Salem, and Tiruchirappalli, combined with untreated municipal sewage and agricultural runoff containing pesticides and fertilizers, elevate biochemical oxygen demand (BOD) and chemical oxygen demand (COD), promoting eutrophication and algal blooms particularly in downstream areas such as Thanjavur and Namakkal.[45] Total dissolved solids (TDS) levels exemplify this deterioration, surging from 57 mg/L near Madikeri in Kodagu to 1,750 mg/L at Mettur dam, reflecting cumulative pollutant accumulation.[46] Untreated wastewater discharges, estimated at 0.5 million liters per day in Kodagu alone, further exacerbate toxicity from domestic and tourism-related sources.[46] Deforestation and associated land conversion have intensified soil erosion and sedimentation, reducing reservoir capacities and degrading riparian habitats. In Kodagu district, forest cover declined by 28% between 1977 and 1997, supplanted by coffee plantations that expanded by 4,000 hectares from 2007 to 2017, contributing to Karnataka's 43% share of India's coffee production.[46] Similarly, Brahmagiri Wildlife Sanctuary lost forest cover from 93.33% in 1973 to 87.66% in 2016, accelerating siltation in upstream reservoirs like Karapuzha in Wayanad.[45] Urbanization compounds this through conversion of paddy fields to resorts and infrastructure, straining water resources; for instance, facilities like Club Mahindra extract 0.25 million liters daily from sources such as Koothole dam, while Kodagu accommodates 2 million tourists and 0.5 million residents annually.[46] Illegal sand mining disrupts channel morphology and aquatic habitats, with operations in areas like Kushalnagar exceeding permissible depths of 1 meter to reach 6 meters, mobilizing 10,000 lorry-loads daily and eroding banks while elevating turbidity.[46] [45] Over-extraction for irrigation, favoring water-intensive crops like paddy and sugarcane, depletes base flows and groundwater, amplifying vulnerability to seasonal deficits evidenced by a 46% monsoon rainfall shortfall in 2023 and an 8 mm annual decline in Madikeri from 1956 to 2016.[46] These factors converge to erode biodiversity, with the basin hosting 148 fish species including 17 endemics; pollution and flow alterations have rendered species like the hump-backed mahseer critically endangered, alongside broader declines in native fish stocks due to contaminated waters and habitat fragmentation.[46] [45] Eight fish species are now classified as critically endangered or endangered, underscoring the cascading ecological toll from nutrient overload, metal contamination (e.g., arsenic, zinc, chromium), and physical alterations.[45]Water Resource Management
Dams, Reservoirs, and Infrastructure
The Kaveri River's infrastructure includes ancient and modern dams and reservoirs developed primarily for irrigation, flood control, and hydroelectric power generation. The oldest surviving structure is the Kallanai Dam, also known as the Grand Anicut, constructed around 150 CE by the Chola king Karikala across the Kaveri near Thanjavur in Tamil Nadu. This unhewn stone barrage, measuring 329 meters long, 20 meters wide at the base, and 5.4 meters high, diverts river flow into channels irrigating over 68,000 hectares without a large impounding reservoir.[47] It exemplifies early hydraulic engineering, relying on the river's natural gradient to distribute water across the delta region.[48] In the upper basin within Karnataka, the Krishnarajasagar (KRS) Dam, located in Mandya district, represents a key modern addition. Construction began in 1911 and completed in 1931 across the main Kaveri channel, forming a reservoir with a gross storage capacity of 49.45 thousand million cubic feet (TMC).[49] Designed by engineer M. Visvesvaraya as a gravity dam using surki mortar masonry, it supports irrigation for approximately 300,000 hectares in the Mysore Plateau via extensive canal networks and generates hydroelectric power.[50] Upstream and on tributaries, supporting reservoirs include the Hemavati Dam (completed 1979 on the Hemavati River in Hassan district, capacity approximately 36 TMC), Kabini Reservoir (on the Kabini River, capacity 55.52 TMC), and Harangi Reservoir (on the Harangi River, capacity 7.2 TMC), which collectively augment KRS storage and regulate flows for downstream release.[51][52] Further downstream in Tamil Nadu, the Mettur Dam, built between 1925 and 1934 across the Kaveri in Salem district, impounds the Stanley Reservoir with a capacity of 93.47 TMC at full reservoir level.[53] This masonry gravity dam, 1,700 meters long and up to 54 meters high, facilitates irrigation across the Kaveri delta through the Grand Anicut system and supports a 40 MW hydroelectric plant.[54] Additional infrastructure on tributaries, such as the Amaravati Dam (capacity 9.32 TMC on the Amaravati River), enhances regional water storage.[55] These facilities, while enabling agricultural productivity, have contributed to hydrological alterations and interstate allocation tensions by modifying natural flow regimes.[56]| Dam/Reservoir | River/Tributary | State | Completion Year | Capacity (TMC) | Primary Purposes |
|---|---|---|---|---|---|
| Kallanai (Grand Anicut) | Kaveri | Tamil Nadu | ~150 CE | N/A (diversion) | Irrigation diversion |
| Krishnarajasagar (KRS) | Kaveri | Karnataka | 1931 | 49.45 | Irrigation, hydropower |
| Hemavati | Hemavati | Karnataka | 1979 | ~36 | Irrigation, water supply |
| Kabini | Kabini | Karnataka | 1974 | 55.52 | Irrigation, hydropower |
| Mettur (Stanley Reservoir) | Kaveri | Tamil Nadu | 1934 | 93.47 | Irrigation, hydropower, flood control |
