This year’s July was the worst month for Tamil Nadu in the last 50 years in terms of realisation of the State’s share of the Cauvery water.

For the entire month, the realisation this time did not even cross the one thousand million cubic feet (tmcft)-mark. It was 0.698 tmcft against the stipulated 31.24 tmcft. Biligundulu is the measuring site for the inflow since the enforcement of the Cauvery Water Disputes Tribunal’s final award in 2013, whereas the Mettur dam was the reference point up to 2012.

As far as Bilingundulu is concerned, the previous lowest during July was 2.441 tmcft in 2003. The same month recorded the lowest for Mettur too, when the State got 1.5 tmcft. The other years of very low realisation include 1987 (Biligundulu-3.392 tmcft and Mettur-2.286 tmcft) and 2012 (4.153 tmcft and 1.033 tmcft).

A study carried out by the High Level Technical Team on Cauvery, which was constituted by the Supreme Court in 2016, shows that as regards to July, Mettur’s 25-year-long average realisation was 33.7 tmcft and the 42-year-long average realisation was 36.2 tmcft. In respect of Billigundulu, the respective average figures for July were 36.871 tmcft and 39.087 tmcft.

The reason why the team considered the average figures for 25 years and 42 years was that the year in question — 2016 — marked the completion of 25 years since the Cauvery Water Disputes Tribunal gave the interim order in June 1991. Also, the year pointed to the fact that 42 years had lapsed since certain clauses of the 1924 Cauvery Accord, which was signed between the then Madras Presidency and the princely State of Mysore, came up for review.

According to the application filed by the Tamil Nadu government before the Supreme Court on Monday, the realisation of the Cauvery water at Biligundulu as on August 2 was 3.687 tmcft. (June - 2.915 tmcft; July - 0.698 tmcft; and August - 0.074 tmcft). In the first two months, the State should have realised 40.43 tmcft as per the Tribunal’s final award, which has been amended by the Supreme Court.