After four years, Tamil Nadu has been experiencing unusually high inflows on the Cauvery during the southwest monsoon (June-September).
It was during the 2018-19 water year (June-May) that the cumulative realisation for the monsoon was nearly 346 thousand million cubic feet (tmc ft), of which 125 tmc ft came in July and 177 tmc ft in August. This year, as on August 11 (only up to which the Central Water Commission has formally shared the data with the riparian States), the aggregate realisation was around 248 tmc ft, of which nearly 107 tmc ft was recorded in July and 125 tmc ft this month.
Though the State had received relatively higher inflows during the 2019 monsoon, it did not receive as much as it got in 2018 or it has been getting now. Three years ago, the total realisation during the southwest monsoon was about 173 tmc ft.
Since the final award of the Cauvery Water Disputes Tribunal was notified in the gazette of the Central government in February 2013, the State got more than its share during the period on four occasions (2013, 2014, 2018 and 2019), barring the present. According to the final award, the quantity stipulated for the monsoon was 134 ft, which was later revised by the Supreme Court to 123.14 tmc ft.
For the entire water year, the State is to get 177.25 tmc ft, the quantity prescribed by the Supreme Court in February 2018 when it modified the Tribunal’s final order. As against this figure, the overall excess quantity received by Tamil Nadu is approximately 71 tmc ft. But if the quantity stipulated for the elapsed period (June 1 to August 11) is considered, the difference is a surplus of around 191 tmc ft.
On Tuesday, water in the Mettur dam remained at the full reservoir level of 120 ft, with the storage being 93.47 tmc ft. Almost the entire amount of inflow — 69,570 cubic feet per second (cusecs) — was being let into the river, while the discharge through the canal was 400 cusecs. Two other reservoirs on the Cauvery system — Bhavanisagar and Amaravathi — were nearly full. Bhavanisagar had a storage of 30 tmc ft and Amaravathi, 3.87 tmc ft.