The 780-megawatt (MW) Idukki hydroelectric project, which enjoys a special place in the history of modern Kerala and the State’s power system, is turning 50 this month.
The ‘birthday’ falls on February 12. It was on that day in 1976 that the then Prime Minister Indira Gandhi dedicated the first stage of the project to the nation. The Kerala State Electricity Board (KSEB), which owns the project, is gearing up to celebrate the occasion “with grand and extensive programmes that reflect its historic and technical significance,” as noted in a January 30 KSEB order on the golden jubilee celebrations.
Located in Idukki district, the hydroelectric project is Kerala’s largest and continues to be the mainstay of the State’s hydropower generation. The three dams associated with the project — the grand 169.16-metre-high Idukki arch dam spanning the Kuravan and Kurathi hills and the Kulamavu and Cheruthoni dams as well as the underground power station at Moolamattam — are considered engineering marvels.
The three dams, in the Periyar river basin, impound the reservoir. The catchment area spans an area of about 650 sq km. The spillway of the reservoir is on the Cheruthoni dam. The annual power generation capability of this project is estimated at 2,398 million units (mu).
The Moolamattam power house has six generators, each having a capacity of 130 MW. The first stage, inaugurated by Indira Gandhi in 1976, consisted of three generators. The second stage, commissioned in 1986, raised the capacity by adding three more.
Dating back to 1919
The history of the Idukki power project dates back to 1919. Then, it was a “small and modest scheme” meant to harness the waters of the Periyar for power generation using a small dam in Idukki, notes the KSEB’s operation and maintenance manual for the Idukki, Cheruthoni and Kulamavu dams published in June 2020. In 1949, the Electricity department submitted a preliminary report to the Travancore-Cochin government. The project attained its present dimensions after Independence. It was eventually developed with Canadian assistance.
In its order setting out the plans for the golden jubilee celebrations, the KSEB management notes, “The 780 MW Idukki Hydro Electric Project is the largest and most prestigious power station in the State and is a symbol of engineering excellence and dedication.”
Published – February 02, 2026 09:38 pm IST
