Incessant rains and revival of south-west monsoon, which has gained vigour in the Cauvery catchment area in south Karnataka, has augmented the rate of inflow into dams and the corresponding outflow.
The Krishnaraja Sagar (KRS) across the Cauvery at Srirangapatana in Mandya district and Kabini reservoir across the Kapila at Beechanahalli in H.D. Kote taluk of Mysuru district, have been full since July.
Full FRL in July
But with the increase in the inflow — and KRS having attained the Full Reservoir Level (FRL) of 124.8 feet as early as July — the dam authorities have no option but to match the rate of inflow with proportionate outflow.
The inflow into KRS on Friday morning was at the rate of 65,733 cusecs while the outflow was 80,013 cusecs. The inflow into the Kabini was at the rate of 14,187 cusecs and the outflow 15,000 cusecs. The cumulative outflow on Friday from both the reservoirs was at the rate of 95,000 cusecs.
This has been the scenario in both KRS and Kabini dam since the last few days. As a result, the quantum of cumulative discharge from both the dams since June 1 has crossed 136 tmcft. While 93 tmcft has flown from KRS since June, 43 tmcft has been released from Kabini.
Contrast to last year
This is in contrast to the cumulative discharge of 53 tmcft from both KRS and Kabini reservoir from June till August 5, 2021, as per the figures maintained by the Karnataka Sate Natural Disaster Monitoring Centre ).
During the same period in 2020, the cumulative outflow from both KRS and Kabini was much lower and it was 33 tmcft owing to delayed onset of monsoon.
The State has to release 123.14 tmcft from June to September, to Tamil Nadu as stipulated by the Cauvery Water Disputes Tribunal while the total release during a water year (from June to May) is 177.25 tmcft. But the cumulative outflow from both the dams has crossed 136 tmcft so far this year. This does not include water accrued owing to rains in the catchment area in the downstream of both the reservoirs.
Meanwhile, more rainy days are forecast for Kodagu and Chikkamagaluru which are the catchment area for the Cauvery and the Hemavati respectively. The Indian Meteorological Department has already declared a red alert for Kodagu till August 6, indicating that rains will intensify.
Bhagamandala, near Talacauvery, from where the Cauvery originates, recorded 145.40 mm of rainfall during the 24-hour period ending 8.30 a.m. on Friday. Napoklu recorded 133.40 mm and Srimangala received 80.80 mm of rainfall during the same period.
This has been the trend since the last few days with no let-up in the rains and hence the inflow to KRS is expected to remain high for a few more days.