A Special Bench of the Supreme Court, led by Chief Justice of India Dipak Misra, on February 16 pronounced the verdict on appeals filed by Tamil Nadu, Karnataka and Kerala against the final award of the Cauvery Waters Disputes Tribunal (CWDT) in 2007 on the allocation of water to them. It directed Karnataka to release 404.25 tmcft water annually to TN which was earlier awarded 419 tmcft water by CWDT. Karnataka will get an additional 14.75 tmcft, totalling 284.75 tmcft. The verdict is valid for 15 years. 

Unlike major north and north-eastern rivers like Indus, Ganga and Brhamaputra which originate from permanent glaciers, Cauvery is fed by seasonal monsoons and tributaries. It gets excess inflows in times of heavy monsoon, and experiences drought-like situation when scanty rainfall occurs. As irrigation needs of farmers are not met, Karnataka and Tamil Nadu engage in a ritual of blame game. 

In accordance with Section 4 of the Inter-State Water Disputes Act, 1956, the National Front government headed by VP Singh constituted the Cauvery Water Disputes Tribunal on June 2, 1990. It gave an interim award on 25 June 1991. In coming up with this award, the Tribunal calculated the average inflows into Tamil Nadu over a period of 10 years between 1980–81 and 1989–90 and the extreme years (of drought and floods) were ignored from this calculation. 

The average worked out to 205 TMC which Karnataka had to ensure reached Tamil Nadu in a water year.  Karnataka rejected the interim award and issued an ordinance. However, the Supreme Court struck down the ordinance and upheld the award which was subsequently gazetted by the government of India on 11 December 1991. In 1998, the Cauvery River Authority (CRA) delivered its final award on February 5, 2007. 

While considering that the total availability of water the Cauvery basin spread across the 4 states is 740 TMC in a "normal year" the Tribunal has allocated the water as follows: Tamil Nadu: 419 TMCft; Karnataka: 270 TMC, Kerala: 30 TMC, and Pondicherry: 7 TMC.  Karnataka feels short-changed as it feels that it has emerged even worse-off than what the interim order awarded it, which had led to massive protests in the state.  

(Courtesy: Outlookindia.com. Detailed story at https://www.outlookindia.com/website/story/the-cauvery-water-dispute/233817)