People living in several regions of east and central Kerala were pushed into panic on Friday as the massive outflow of water from the giant Idukki hydel reservoir swallowed farmlands, destroyed many houses , uprooted scores of trees and pulled down river banks after all the five shutters of the Cheruthoni dam, one of the three dams of the reservoir system, were opened.
The Kerala State Electricity Board (KSEB) opened all the five shutters of the Cheruthoni dam to drain out a reported volume of 750,000 liters of water per second (750 cumecs – cubic meters per second) into the Cheruthoni river from the 60-square kilometer reservoir in which the water level was rapidly rising, threatening to hit the maximum storage level of 2,403 feet.
Some unconfirmed reports said that the outflow from the reservoir Friday night was at 800 cumecs. All the five gates of the dam were opened by 1.30 PM Friday releasing water at 450 cumecs but they had to be lifted further as there was no decrease in the inflow to the reservoir from the catchment areas that were receiving extremely heavy rainfall.
Though the Cheruthoni dam shutters had been opened in 1981 and 1992, this was the first time all the five shutters were being lifted since the commissioning of the Idukki hydel project of 780-MW installed capacity in 1976. Also, it was for the first time that such huge volumes of water being released from the reservoir.
The KSEB was forced to release such massive volumes as inflow remained much higher than the volume of the water being released through the shutters and that being used for generating electricity. At 1.00 PM Friday, the rate of the total water flowing out — through the shutters and for power generation — was 566 cumecs while the inflow rate was 900 cumecs.
At that time, the reservoir water level stood at 2,401.6 feet which rose further to 2401.76 feet by 5.00 PM. There was a very small dip in the inflow late Friday evening but KSEB sources refused to give any assurance on bringing down the outflow while the Idukki district authorities announced that the red alert issued earlier would remain in force in the district till Monday.
The process at the Idukki project pushed the people living on the banks of the Cheruthoni river into which the dam water is being released and River Periyar with which it meets a kilometer downstream into fear and anxiety as water gushed down swallowing river banks, uprooting trees, inundating farmlands and destroying houses and other buildings.
The authorities issued red alert for all the people living downstream up to Aluva near Kochi, some 80 kilometers away, where River Periyar was already in a swollen condition. About 200 families had been shifted to safer places in Idukki district while steps were on to shift several thousand families in the Aluva region of Ernakulam district.