After the water crossed the blue alert level, a shutter of the Cheruthoni dam of the Idukki reservoir was opened at 6 a.m. on Tuesday.
Shutter number 3 was initially raised by 40 cm, and, at 8.30 a.m., it was further lifted to 60 cm when the water level reached 2,401.58 ft. Within a 24-hour period from Monday morning, the water rose nearly one foot following the release of a high volume of water from the Mullaperiyar dam and heavy rainfall on the catchment area of the Idukki dam from Monday afternoon.
According to KSEB officials, the high volume of water released from Mullaperiyar resulted in the steady rise in the water level in the Idukki dam. The catchment area of Mullaperiyar received heavy rainfall, and Tamil Nadu released 12,654.09 cusecs of water to the Periyar by Monday night.
According to a dam safety official, the shutter was opened as a high volume of water was released to the Periyar from Mullaperiyar and also in consideration of chances of continued rainfall. After the dam shutter was opened, the water level dropped to 2,401.52 ft at 3 p.m. on Tuesday.
Tamil Nadu action
Meanwhile, Tamil Nadu continued to open the spillway shutters of the Mullaperiyar dam at night despite a request from the Kerala government to limit the action. After a high volume of water was released on Monday night, several houses on the banks of the Periyar were flooded.
Mullaperiyar protection council chairman K.A. Mohandas said the government should take immediate steps to ensure the protection and safety of the people residing along the downstream areas of the dam. The continuous opening of shutters at night caused them problems, he said.
When the water in the Idukki dam reached the orange alert level, a decision to release the water was taken by the rule committee meeting in Thiruvananthapuram. The upper rule curve fixed by the Central Water Commission (CWC) was applicable till November 20. The full reservoir level (FRL) is 2,403 ft., which is the current upper rule level of the Idukki reservoir.
Ever since the north-east monsoon set in, the Cheruthoni dam has been opened four times. It was first opened on October 19 and closed on October 27, releasing 46.296 mcm of water. The dam was opened again on November 14 and closed on November 16, releasing 8.616 mcm of water. It was opened again on November 18 and closed on November 20 night when a huge tree was detected floating towards the shutters. A volume of 14.465 mcm of water was released in this phase.