Idukki dam to be opened after 3 yrs; a quick glance at what happened in 2018

Idukki: After the flood havoc in 2018, the shutters of Idukki dam will be opened again on Tuesday by 11 in the morning. The shutters are going to be opened for the fifth time in the history of the dam. Three shutters of Cheruthoni dam, which is part of the Idukki hydro power project, will be opened by 35 centimeters each. The district administration directed the people dwelling on the banks of Periyar river to stay vigilant. One lakh litres of water per second will flow out of the dam if the shutters are opened.

According to the rule curve to regulate the water flow, red alert will be sounded when the water level reaches at 2397.8 feet. Though it is allowed to wait till the water level reaches 2398.86 feet, the shutters need to be opened to maintain it safely. Idukki arch dam and Kulamavu dams do not have shutters. Only Cheruthoni dam has shutters to release water.

Last opened in 2018

When the dam is about to be opened after three years, the authorities have made all preparations. Last time, all five shutters of the dam were opened on August 9 in 2018. It was after 26 years the dam shutters were opened. However, the subsequent flood affected several people living on the banks of Periyar.

The water level in the dam had reached 2395.05 on July 30, 2018. It was decided to conduct trial run when the water level reaches 2398 feet. However, water level rose due to unexpected rainfall and landslide in the catchment areas. On August 9, water level touched 2398.8 feet. The third shutter was opened at 12.30 pm. But the water level kept rising and all five shutters were opened on the following day.

Two shutters were closed on August 13 evening when rains receded. But rainfall intensified again and all five shutters were opened again. The places on the river bank submerged the heavy current leaving hundreds of people in distress. Later, the dam shutters were closed gradually. Controversies erupted over the lapses on the part of authorities regarding the dam opening.

1500 cumecs water released

When the first shutter was opened on August 9, 2018, 150 cumecs (cubic metre per second) of water was released. When all five shutters were opened, the water flow increased to 750 cumecs. When the shutters were closed and later reopened, 1500 cumecs water was released from the dam. The water released in a month was sufficient to produce about 1500 million units of power.