The Idukki Dam is a double curvature arch dam constructed across the Periyar River in a narrow gorge between two granite hills locally known as Kuravan and Kurathi in Idukki, Kerala, India. At 168.91 metres (554.2 ft), it is one of the highest arch dams in Asia. It is
constructed and owned by the Kerala State Electricity Board. It supports a 780 MW hydroelectric power station in Moolamattom, which started generating power on 4 October 1975.The dam type is a concrete, double curvature parabolic, thin arc dam. The Indo-Canadian project was inaugurated by the Prime Minister Indira Gandhi on February 17, 1976.
This dam was constructed along with two other dams at Cheruthoni and Kulamavu. Together, the three dams and Two saddle dams, Kulamavu Saddle Dam (Near Junction) and Kulamavu Saddle Dam (Right Bank) have created an artificial lake that is 60 km2 (23 sq mi) in area. The stored water is used to produce electricity at the Moolamattom Power house, which is located inside nearby rocky caves.
Narakakkanam, Azhutha, Vazhikkadavu, Vadakkepuzha and Kuttiar diversion schemes were later added to augment the Idukki reservoir.