Delay in southwest monsoon’s arrival leaves T.N.’s water managers worried about Cauvery river

With the Mettur dam, the lifeline of the Cauvery delta, getting ready for the commencement of water release for irrigation on the customary date of June 12, the delay in the south-west monsoon’s arrival is causing anxious moments to Tamil Nadu’s water managers, especially those monitoring the Cauvery’s flows. 

With the Mettur dam, the lifeline of the Cauvery delta, getting ready for the commencement of water release for irrigation on the customary date of June 12, the delay in the south-west monsoon’s arrival is causing anxious moments to Tamil Nadu’s water managers, especially those monitoring the Cauvery’s flows. 

The monsoon has already missed its onset date of June 4 over Kerala, though the Meteorological Department, while forecasting the date last month, provided a margin of four days. As on Tuesday evening, there was no clarity over the advent of the rains, in the light of the influence of a developing cyclonic system over the southeast Arabian Sea. Water managers are also worried over the pattern of inflows that Tamil Nadu may get in the coming months if the onset gets delayed further.

As on the morning of June 6, 2023, Mettur dam’s water level stood at 103.7 ft (full level: 120 ft) with the storage being 69.72 thousand million cubic feet (TMC) against its capacity of 93.47 TMC. On the corresponding day last year, the figures of water level and storage were higher, 114.63 ft and 85.164 TMC respectively.

Rainfall during the monsoon, over the catchment of the Cauvery in Karnataka and Kerala, has been taken into account while arriving at the quantum of water to be released from Karnataka to Tamil Nadu. Of the total annual quantity of 177.25 TMC to be provided under the Supreme Court’s judgement of 2018, Tamil Nadu is to get 123.14 TMC during June-September, which marks the period of the monsoon.  

Since 1991, on 20 occasions, Tamil Nadu realised less than its share of water during June-September, as stipulated by the Cauvery Water Disputes Tribunal in its interim (1991) and final (2007) orders and by the Supreme Court even though, at the end of the water year (June-May), in some years, the State had received a higher quantity than the overall annual figure, the latest being in 2021-22. 

As for coverage in the Cauvery delta under the short-term Kuruvai season, it remains to be seen whether the State will be able to continue with its dream run of 2021 and 2022 or hold on to its normal coverage of 3.2 lakh acres. The coverage was 4.9 lakh acres in 2021 and 5.36 lakh acres in 2022.