The stored water is used to produce electricity at the Moolamattom Power house, which is located inside nearby rocky caves.
[1] Narakakkanam, Azhutha, Vazhikkadavu, Vadakkepuzha and Kuttiar diversion schemes were later added to augment the Idukki reservoir .
The idea of constructing a dam for power generation was first conceived in 1919 in a report submitted by Italian engineer Jacob to the Travancore government, which was rejected.
As per history, Shri Chemban Karuvellayan Kolumban,the head of 'Oorali' tribe during 1922, showed the way to the Malankara Estate Superintendent W.J.John and his friend AC Thomas Edattu, who were on hunting trip to forests near the present Arch Dam.
Upon hearing the legend of Kuravan and Kurathi Hills, Thomas impressed by the sight of water flow between the mountains; suggested the spot suitable for an Arch dam.
[3] In 1932, W.J.John submitted a report to the Government of Travancore on the possibility of constructing a dam at Idukki for Power Generation.
Italian engineers Angelo Omedayo and Clantheyo Masele conducted a study in 1937 but things didn't go forward.
It was during 1956 that the Central Water Commission conducted a detailed investigation based on the Government's request.
This project is situated in Idukki District and its underground power house is located at Moolamattom which is about 43 km (27 mi) from the dam.
[7] The tail waters flowing to Kudayathurpuzha through tunnel and open channel is diverted for irrigation purposes in the Muvattupuzha Valley.
Earlier, there was a blanket ban on public entry to the dam due to security reasons.
The birds of Idukki are Jungle fowl, myna, laughing thrush, black bulbul, peafowl, woodpecker, kingfisher, eagle etc.