Tamil Nadu, Karnataka, Kerala, and Puducherry had filed petitions seeking modification of Cauvery Tribunal's final order.
The dispute dates back to the Madras-Mysore agreements of 1924. It was in 1990 when the Centre created a tribunal to examine the conflict and address the water shortage. The CWDT had unanimously passed an order on how the water should be shared between the states after determining the total availability of water in the Cauvery basin.
The apex court during the period of trials had passed several orders directing the Karnataka Government to provide a certain amount of Cauvery water to Tamil Nadu.
Security tightened in Bengaluru
Security has been tightened in Bengaluru.
Speaking to reporters, Bengaluru police commissioner T Suneel Kumar said 15,000 police personnel would be deployed for duty.
In addition to this, personnel of Karnataka State Reserved Police and other forces would be deployed.
"Special attention will be given to the sensitive areas where riots had taken place in the past," the commissioner said.
Karnataka has been claiming that the Krishnaraja Sagar dam is left with water only to cater to Bengaluru.
Owing the geographic peculiarities of the State, Tamil Nadu has been dependent on water from the rivers in Karnataka and Kerala for a long time now. The dispute between Tamil Nadu and these two states also has a long history.
Differences between Tamil Nadu and Karnataka on sharing of water in the Cauvery river, which is one of the main sources of water for irrigation in the agricultural lands of the Cauvery delta, have been in existence from the time of two agreements signed during the period of British government ruling the country.
Two agreements were signed between the then Madras Presidency and the State of Mysore, in 1892 and 1924. Karnataka claimed that the water allocated to it from the river was inadequate and that the agreements favoured the Madras Presidency. Tamil Nadu has time and again claimed that the irrigated land in the State has increased over a period of time and the entire region is dependent on the water from the river for agriculture and survival.
The tussle between the two states related to the release of water from Karnataka continued over all these years and worsened whenever sparse rainfall brought down the level of water in the river, such as in 1995 and 2002. A Cauvery Fact Finding Committee was constituted to look into the issue, and a final report was submitted by the committee on 1973. Following this, discussions were also held on the creation of a Cauvery Valley Authority. The Government of India had set up a Cauvery River Authority and a monitoring committee, with participation from the Centre and both the states.
Efforts did not put an end to the dispute and people in both the states agitated at the slightest provocation over the river dispute. Even film stars joined the protest and Karnataka's decision to build a dam across the river created another tussle, following which Tamil Nadu approached the court to set up a tribunal under the Interstate River Water Disputes Act of 1956.
Tribunal's verdict in February 2007
A tribunal, constituted by the Government of India under the direction of the Supreme Court, came out with its final verdict in February, 2007, under which Tamil Nadu was entitled to get around 419 billion cubic feet of water, Karnataka, 270 billion cubic feet, Kerala, 30 bllion cubic feet and Puducherry was to get seven billion cubic feet of water, according to earlier reports.
However, the dispute continued after both the States filed petition with the tribunal to review the decision.
In 2012, the Cauvery River Authority directed Karnataka to release 9,000 cusecs of water to Tamil Nadu. Upon violation of this directive by Karnataka, Tamil Nadu approached the Supreme Court and received a favourable order.
Following a fresh row, the Supreme Court asked the Centre to set up a Cauvery Water Dispute Tribunal, based on which, the Government of India notified the final award of the tribunal in February 2013.
What Tamil Nadu and Karnataka have to say -
Tamil Nadu has been arguing for a Cauvery Water Board and approached the Supreme Court seeking directions to form the Board. It has also sought damages to the tune of around Rs 2,400 crore from Karnataka for not following orders of the tribunal. While a supervisory committee asked Karnataka to share the water, the state's Chief Minister Siddaramaiah, on June 2, 2013, said that the state cannot release 134 TMC of water to Tamil Nadu between June and September. Due to this, the dispute once again made its way to the court against the supervisory committee and Karnataka.
The dispute was given fresh impetus when Tamil Nadu approached the Supreme Court in August, 2016, after Karnataka stated that it had no water in the reservoirs to share. It was based on this complaint, that the Supreme Court asked Karnataka to release 15,000 cusecs of water for 10 days.
On October 18, 2016, the Supreme Court had asked Karnataka to release 2000 cusecs of Cauvery water per day to Tamil Nadu till further orders.
On January 9, 2017, the Tamil Nadu Government had sought a compensation of Rs 2,480 crore from Karnataka for not releasing water to the state despite getting the Supreme Court directive to do so.