The uneven rainfall since the start of the water year on June 1 has impacted the Idukki reservoir level, which has started to decline after initially increasing following the summer rain.
The water level receding after the middle of June is rare. The water level first started to rise in May and it declined again. However, with the southwest monsoon it increased and then started declining again from Thursday. This is for the second time the water level has started to decline, says M.P. Saju, assistant engineer, Dam Safety, Kerala State Electricity Board.
Normally, the water level starts to show a rising trend only after two to three days of continuous heavy rainfall after the start of the monsoon. However, the pattern has changed since 2018 and the water level increasing with the summer rain is rare in the Idukki reservoir.
The water level normally touches the lowest level prior to the water year and the highest storage level will be by October-November. The water level on Saturday was 2,337.96. ft with a rainfall of 20.6 mm on Friday. The power generation at Moolamattom is below normal now. It was 4.43 million units on Friday. Power generation had reached the highest level during the end of the summer season.
The water level is over 10 ft below now compared to the water level on the same day last year (2,349.30 ft). The present storage level is 35.96% whereas it was 46.23% on the same day last year.
The poor storage level is due to the erratic rainfall since June 1. The water level has not dipped to the lowest level prior to the southwest monsoon.
As per the rule curve fixed by the Central Water Commission, the blue alert level is 2,365 ft, orange alert 2,371 ft, and red alert 2,372 ft. The full reservoir level is 2,403 ft.