The Cauvery river water dispute, primarily between Tamil Nadu and Karnataka, dates back to the 19th century. A chronology of the riparian wrangle, compiled by T Arvind

The agreement signed between Madras Presidency and the princely State of Mysore in 1924 lapsed in 1974.

May 1990: Supreme Court directs Centre to constitute Cauvery Water Dispute Tribunal, a demand made by Tamil Nadu since 1970.

June 2, 1990: Centre notifies Cauvery Water Disputes Tribunal (CWDT).

January 1991: The CWDT rejects Tamil Nadu government's plea for interim relief. TN appeals the rejection in Court.

April 1991: Supreme Court directs the CWDT to entertain TN's petition for interim relief.

June 1991: The CWDT announced an interim award: Karnataka ordered to release 205 tmcft. In a move to nullify the interim awards, Karnataka government passes an Ordinance. Supreme Court intervenes, strikes down Karnataka's ordinance and upholds the interim award of the CWDT. Karnataka refuses to oblige.

December 11, 1991: The Interim award is published in the Government of India gazatte.

July 1993: Tamil Nadu Chief Minister Jayalalithaa goes on a sudden fast at the MGR memorial in Chennai demanding the Tamil Nadu's share of water as stipulated by the interim order.

August 1998: Centre constitutes Cauvery River Authority to ensure the implementation of the interim award of CWDT.

September 8, 2002: Cauvery River Authority chaired by Prime Minister A.B. Vajpayee directs Karnataka to release 9,000 cusecs (0.8 tmcft) of Cauvery water to Tamil Nadu. Tamil Nadu unhappy with the order, says it will move Supreme Court.

The Cauvery tangle

September 13, 2002: Congress MP from Tamil Nadu Mani Shankar Aiyar blames the AIADMK for not raising the issue in Parliament.

September 15, 2002: Tamil Nadu Chief Minister Jayalalithaa refutes Mani Shankar Aiyar's charges against her and issues a 9-page statement on the Cauvery issue.

September 18, 2002: Protesting against the release of water to Tamil Nadu, a Karnataka farmer jumps into the Kabini Reservoir, dies.

September 25, 2002: Karnataka farmers explain the distress situation to the visiting Cauvery Monitoring Committee panel.

October 12, 2003: Water experts from the Centre express their helplessness in coming to the rescue of Tamil Nadu in inter-State river disputes; say their hands are tied. They are of the view that the Centre has not been pro-active in ensuring effective functioning of the Cauvery River Authority.

July 17, 2005: Karnataka refuses to implement the distress sharing formula and rules out Cauvery water to Tamil Nadu.

April 13, 2006: After six-rounds of talks, farmers of Karnataka and Tamil Nadu try to find a solution to the problem of water-sharing between the riparian States .

Feb. 5, 2007: After 16 years, Cauvery Water Disputes Tribunal gives final award. Tribunal holds as valid the two agreements of 1892 and 1924 executed between the Governments of Madras and Mysore on the apportionment of water to Tamil Nadu.

Final Order of the Cauvery Water Disputes Tribunal

Feb. 12, 2007: Karnataka protests tribunal final award. Observes State-wide bandh on the issue.

Feb. 18, 2007: Bangalore IT professionals protest against the "biased" award of the Cauvery Water Disputes Tribunal.

March 18, 2007: Jayalalithaa undertakes a token fast in Chennai demanding publication of the final award of the Cauvery Water Disputes Tribunal in the Official Gazette of the Centre.

June 30, 2008: Senior counsels of Karnataka on the Cauvery dispute meet top officials of the State government.

July 28, 2010: Cauvery river rises owing to good rainfall in the catchment areas in Kodagu district.

Dec 2, 2010: The Stanley reservoir, the lifeline of the Cauvery delta, touches the full reservoir level (FRL) of 120 feet, bringing cheers to water managers in Tamil Nadu.

A report in The Hindu says that between 1991 and 2011 -- in 20 years, Tamil Nadu realised less water on 13 occasions in June-September.

May 19, 2012: Jayalalithaa seeks immediate Cauvery River Authority meet

Sept. 19, 2012: After nine years, at the seventh CRA, Manmohan Singh directs Karnataka to release 9,000 cusecs of Cauvery water to Tamil Nadu at Biligundlu Both the CMs -- Jayalalithaa and Jagadish Shettar term it "unacceptable". This is the first CRA meet since the UPA came to power at the Centre in 2004.

Sept. 28, 2012: Supreme Court slams Karnataka government for not complying with PM's direction at the CRA.

Feb. 29, 2013: Centre notifies the final award of the Cauvery Water Disputes Tribunal (CWDT). The Central government was mandated to constitute the Cauvery Management Board (CMB) simultaneously with the gazette notification of the final award of the Tribunal dated February 19.

March 10, 2013: Tamil Nadu Chief Minister says that she will strive for formation of Cauvery Water Board during a felicitation ceremony organised in Thanjavur for her efforts to get the final award notified in the Union gazette.

March 19, 2013: Tamil Nadu moves Supreme Court to give directions to Water Ministry for constitution of Cauvery Management Board.

May 1, 2013: The Election Commission directs the Union Water Resources Ministry to defer constituting the Cauvery Management Board (CMB) and the Cauvery Water Regulation Committee (CWRC) till May 5 in view ot Karnataka Assembly polls.

May 10, 2013: Supreme Court directs Centre to set up panel to supervise Cauvery water release.

May 24, 2013: Centre notified temporary Cauvery Water (Implementation of the Order of 2007) Scheme, 2013.

May 27, 2013: Cauvery issue will be resolved soon, says Karnataka Law Minister.

May 28, 2013: Tamil Nadu moves Supreme Court, seeks Rs. 2,480-cr damages from Karnataka for not following orders of the Cauvery Water Disputes Tribunal

June 1, 2013: Union Water Resources Secretary chairs the first meeting of the Supervisory Committee which saw Tamil Nadu demanding its share of water for June as stipulated in the award.

June 2, 2013: Water cannot be released as and when TN demands, says Karnataka Chief Minister Siddaramaiah.

June 6, 2013: Karnataka says it cannot release 134 tmcft of water to Tamil Nadu between June and September.

June 12, 2013: Cauvery Supervisory Committee terms the Tamil Nadu's plea for directions to Karnataka for release of Cauvery waters as per the award of the CWDT as not “feasible”.

June 14, 2013: Tamil Nadu decides to file contempt plea against Karnataka for its stand on the Cauvery Supervisory Committee.

June 15, 2013: Chief Minister Jayalaithaa says the Tamil Nadu government will approach the Supreme Court for the formation of the Cauvery Management Board and Cauvery Water Regulatory Authority.

June 26, 2013: Contending that the setting up of a supervisory committee had become a futile exercise, Tamil Nadu moves SC for constitution of Cauvery Management Board.

June 28, 2013: Tamil Nadu files contempt petition in the Supreme Court against Karnataka CM Siddaramaiah for his a defiant stand before the Supervisory Committee

July 15, 2013: Karnataka and Tamil Nadu clash during the third meeting of the Cauvery Supervisory Committee here over latter’s share of the river waters. While Tamil Nadu sought 34 tmcft in July and 50 tmcft for August to save the Samba crop, Karnataka says that it had already released 34 tmcft between June and July 13.

September 8, 2013: Chief Minister Jayalalithaa wants the Centre to instruct Karnataka not to take up any schemes in the Cauvery, including hydro-electric projects, without the prior consent of Tamil Nadu. Taking exception to the neighbouring State’s proposal to build a reservoir across the river at Mekedatu for generation of hydro-electric power, Jayalalithaa on requests the then Prime Minister Manmohan Singh to intervene.

January 6, 2014: Justice Chauhan is Chairman of Cauvery Water Disputes Tribunal. The tribunal had been without a Chairman since April 2012, when Justice N.P. Singh resigned on health grounds. Justice Singh was appointed a few days before his superannuation as a Supreme Court judge in December 1996.

July, 2014: The Cauvery Water Disputes Tribunal meets in New Delhi to hear applications filed by the Centre, Tamil Nadu, Karnataka and Kerala seeking clarification on the final award it had passed on February 5, 2007, allocating the quantum of water for each State.

March 30, 2015: Chief Minister Siddaramaiah informs the Legislative Assembly that the State Government is committed to implementing the Mekedatu dam project proposed across the Cauvery river in Ramanagaram district.

April 23, 2015: Members of Lok Sabha from Tamil Nadu and Karnataka are involved in heated exchanges over the issue of Cauvery water sharing. AIADMK leader P. Venugopal claims that Karnataka is building two reservoirs on river Cauvery and says the move is against the final award of the Cauvery River Water Dispute Tribunal. The then Union Minister Ananth Kumar, who hails from Karnataka, and BJP MP from the State Shobha Karandlaje oppose the AIADMK’s claim.

September 6, 2015: Chief Minister Jayalalithaa writes to Prime Minister Narendra Modi seeking his intervention in the Cauvery issue and requests him to advise the Karnataka Government to release 27.557 TMC ft. of water that is due to Tamil Nadu (till the end of August).

September 16, 2015: The Tamil Nadu government shoots off a letter to the Karnataka government stating that this water year should not be considered as a distress year in terms of rainfall and is contrary to the factual position.

November 18, 2015: Karnataka objects to Tamil Nadu’s plea to release Cauvery water. The Karnataka government tells the Supreme Court that Tamil Nadu’s demand for the release of 45.32 tmcft of Cauvery water proceeds from a wholly erroneous premise that the water year of 2015-16 in the Cauvery basin is a “normal year” and not a “distress year”.

Karnataka says the flows into the Cauvery basin has been drastically less due to the failure of the south-west monsoon in Karnataka and Kerala this year.

August 16, 2016: Tamil Nadu Chief Minister Jayalalithaa tells the Legislative Assembly that she has ordered filing of an interlocutory petition in the Supreme Court seeking release of Cauvery water as per the final award of the Cauvery Water Tribunal.

September 2, 2016: Urging Karnataka to embrace the principle of “live and let live”, the Supreme Court asks the State to consider taking steps to release Cauvery water to Tamil Nadu to help the State continue to “exist as an entity.”

September 5, 2016: The Supreme Court directs the Karnataka government to release 15,000 cusecs of Cauvery water per day to Tamil Nadu for the next 10 days to ameliorate the plight of farmers. Noting that the samba crops in Tamil Nadu will be adversely affected, a Bench — comprising Justices Dipak Misra and U.U. Lalit — directs Karnataka to ensure supply of water to Tamil Nadu.

September 7, 2016: Karnataka begins releasing Cauvery water to Tamil Nadu from as per the Supreme Court order, even as protests against the decision continue to disrupt inter-State movement.

September 11, 2016: Succumbing to political pressure and the wave of public protests, the Karnataka government files a plea to modify a Supreme Court order directing it to share Cauvery water with distressed neighbour Tamil Nadu.

September 12, 2016: In a stern message asking people in Karnataka and Tamil Nadu “to behave”, the Supreme Court refuses a plea by the Siddaramiah government to freeze the September 5 order. The court, however, reduces the quantum of daily water release ordered earlier, from 15,000 cusecs to 12,000 cusecs.

September 12, 2016: One person dies and four are injured in police firing. Mobs attack businesses with Tamil names.

Curfew is imposed in seven police station limits of Bengaluru. The violence virtually paralyses the Bengaluru-Mysuru highway.

Prohibitory orders under Section 144 are imposed in Bengaluru and Mysuru, areas around four reservoirs in the Cauvery basin, and Pandavapura in Mandya district.

September 19, 2016: A technical body, empowered by the Supreme Court, slashes by three-fourths the quantum of Cauvery water that Karnataka is required to release downstream between September 21 and September 30. The Cauvery Supervisory Committee (CSC) orders Karnataka to release 3,000 cubic feet of water per second (cusecs) for the rest of the month.

January 10, 2017: Supreme Court directed Tamil Nadu and Karnataka to file affidavits of witnesses to be examined in the former’s plea seeking about ₹2,500 crore compensation for loss of crops for not releasing Cauvery water in 2012-13.

July 14, 2017: Supreme Court said it would take a balanced view, keeping in mind the interests of the people of both the States. Karnataka sought a reduction in the quantum of Cauvery water it should release to Tamil Nadu from 192 tmcft to 132 tmcft.

September 20, 2017: The Supreme Court reserved its judgment on the appeals filed by Tamil Nadu, Karnataka and Kerala against the final award of the Cauvery Tribunal in 2007 on the allocation of the river water to the three States.

In the final day of the hearing before a Special Bench of Chief Justice Dipak Misra and Justices Amitava Roy and A.M. Khanwilkar, Tamil Nadu reiterated its demand that the Supreme Court should itself appoint the authority and frame the scheme for sharing and management of the water among the three States.

February 16, 2018: Supreme Court reduces the allocation of Cauvery water from Karnataka to Tamil Nadu. The apex court directed the Karnataka government to release 177.25 tmcft of Cauvery water to Tamil Nadu from its inter-state Biligundlu dam. The judgement clarified that Karnataka will now have an enhanced share of 14.75 tmcft water per year while Tamil Nadu will get 404.25 tmcft, which will be 14.75 tmcft less than what was allotted by the tribunal in 2007.

Earlier, in accordance with the 2007 award of the Cauvery Water Dispute Tribunal (CWDT), Karnataka had a share of 270 tmcft of Cauvery water. This will now increase to 284.75 tmcft.