The Tamil Nadu government has sought the Supreme Court’s intervention to make Karnataka immediately release 24,000 cubic feet per second (cusecs) from its reservoirs.It also urged the Court to direct Karnataka to ensure the release of 36.76 TMC (thousand million cubic feet) stipulated for September 2023 as per the Cauvery Water Disputes Tribunal (CWDT)’s final award of February 2007.
This was modified by the SC in 2018.
Cauvery Water Being Shared
- A carefully crafted monthly schedule governs the distribution of water between Karnataka and Tamil Nadu, the two riparian states of the Cauvery basin.
- In a “normal” water year, Karnataka is bound to release 177.25 TMC (thousand million cubic feet) of water from June to May to Tamil Nadu.
- This annual quota includes 123.14 TMC allocated during the monsoon months from June to September.
- The ongoing southwest monsoon season often triggers disputes when rainfall falls short of expectations.
Cauvery River Dispute
- It is known as ‘Ponni’ in Tamil and is a sacred river of southern India.
- It rises on Brahmagiri Hill of the Western Ghats in southwestern Karnataka state, flows in a southeasterly direction through the states of Karnataka and Tamil Nadu, and descends the Eastern Ghats in a series of great falls and drains into Bay of Bengal through Pondicherry.
- Left Bank Tributary: Arkavathi, Hemavathi, Shimsa, and Harangi.
- Right Bank Tributary: Lakshmantirtha, Suvarnavati, Noyil, Bhavani, Kabini, and Amaravathi.
History of Cauvery River Dispute
- Pre- independence period- There were two agreements entered in 1892 and 1924 with respect to sharing of river water between the states of erstwhile Madras Presidency and the kingdom of Mysore.
- 1924 agreement- Karnataka and Tamil Nadu signed an agreement effective for 50 years.
The percentage of water sharing is
- 75% – Tamil Nadu and Puducherry
- 23% – Karnataka
- 2% – Kerala
Dispute
- As the river originates in Karnataka, flows through Tamil Nadu with major tributaries coming from Kerala and drains into the Bay of Bengal through Pondicherry the dispute therefore involves 3 states and one Union Territory.
- The genesis of the dispute is 150 years old and dates back to the two agreements of arbitration in 1892 and 1924 between the then Madras presidency and Mysore.
- It entailed the principle that the upper riparian state must obtain consent of lower riparian state for any construction activity viz. reservoir on the river Cauvery.
- The Cauvery water dispute between Karnataka and Tamil Nadu began in 1974 when Karnataka started diverting water without Tamil Nadu’s consent.
- After several years, the Cauvery Water Disputes Tribunal (CWDT) was established in 1990 to resolve the issue. It took 17 years for the CWDT to reach a final order in 2007, which outlined the sharing of Cauvery water among the four riparian states. In distress years, water would be shared on a pro-rata basis.
- CWDT issued its final award in February 2007, specifying water allocations among the four states in the Cauvery basin, considering the total availability of 740 TMC in a normal year.
- The allocation of water among the four states is as follows: Tamil Nadu – 404.25 TMC, Karnataka – 284.75 TMC, Kerala – 30 TMC, and Puducherry – 7 TMC.
- In 2018, the Supreme Court declared the Cauvery a national asset and largely upheld the water-sharing arrangements determined by the CWDT.