Idukki hydel project, an engineering marvel, turns 50

Idukki: The Idukki hydroelectric project, an engineering marvel built between the Kuravan and Kurathi hills, is turning 50. The Idukki Arch Dam --- India's first such structure --- and Cheruthoni and Kulamavu dams, all built across Periyar River, together form the state's biggest source of hydroelectric power.The project has shone brightly over Kerala's journey forward, ever since it was dedicated to the nation on Feb 12, 1976, by the then prime minister Indira Gandhi. The plan was to mark the golden jubilee year with the commissioning of the Idukki Extension Project but, unfortunately, the work on it has not begun yet. Still, KSEB has lined up a few events to mark the golden jubilee.The extension project mooted during the time of the first Pinarayi govt proposed the installation of four generators of 200 MW capacity each. It would have taken the Idukki hydroelectric project's total power generation to 1,580 MW from the current 780 MW and helped mitigate the state's power shortage. However, 10 of the 12 required approvals are pending.The state govt had entrusted Wapcos, an agency under the Union ministry of Jal Shakti, with the task of preparing a detailed project report and securing necessary permissions. Power minister K Krishnankutty informed the assembly that procedural steps were in progress. The draft environmental impact assessment was completed and the project received first-stage green clearance from the Union ministry of environment, forest and climate change.The hydel project's history dates back to 1932 when W J John, then superintendent of Malankara Estate, explored the region for hunting. He was accompanied by Karuvellayan Kolumban, leader of the Urali tribal community. Kolumban introduced John to the Kuravan-Kurathi hills and Periyar River, which prompted John to analyse the hydroelectric potential of the area. With the help of his brother, a civil engineer, John submitted a report to the erstwhile Travancore govt on the possibility of building an arch dam.In 1937, Italian engineers Angelo Omedayo and Clantheyo Masele also approached the Travancore govt with a project, but it did not go forward. In 1947, P Joseph, an electrical engineer with Travancore govt, recommended linking Periyar and Cheruthoni rivers with a dam, based on John's report. It took another 14 years to finalise the Idukki dam's design. Construction began in 1963 while in 1966, the Canadian govt extended assistance under the Colombo Plan.The Idukki dam was constructed along with the Cheruthoni dam and Kulamavu dam -- the smallest among the three --- to regulate Periyar River. The arch dam's design allows for a 23-40MM horizontal movement when the reservoir reaches full capacity, enabling it to withstand earthquakes.Cheruthoni dam was built to prevent the stored water from flowing out through the Cheruthoni river. Kulamavu dam was constructed to prevent water loss through the Kilivallithodu stream. The Idukki dam has no shutters; water is released using Cheruthoni dam shutters.Power generation takes place at Moolamattom Powerhouse, located 750M beneath Nadukani hills. It is the largest underground hydroelectric power station in the country.K K Karuppankutty, who was the only KSEB chief engineer to hold combined responsibility of both the dams and the powerhouse and retired in 2014 as a member of KSEB's generation board, described the Idukki hydel project as "a remarkable engineering marvel".Idukki Project Generation executive engineer Jumaila Beevi said an administrative sanction for Rs 16 lakh has been given for the golden jubilee celebrations. A reunion of former officials and workers who were part of the project in various phases too will be held. "The role played by the Idukki hydel project in sustaining KSEB and in strengthening the state's power sector is significant," Beevi told TOI.-------------POWER GENERATION BY KSEBHydel 2,052MWDiesel/LSHS 159.96MWSolar 10.50MWWind 2.03MW