Idamalayar Dam is a multipurpose concrete gravity dam locatedbetween Bhoothathankettu and Malakkappara in Ernakulam district of Kerala on the Idamalayar, a tributary of the Periyar River in Kerala, South India. Completed in 1985, with a length of 373 metres (1,224 ft), the dam created a multipurpose reservoir covering 28.3 km2 (10.9 sq mi) in the scenic hills of the Anamalais. The reservoir storage is utilized by a hydroelectric power station which has aninstalled capacity of 75 MW with two units of 37.5 MW capacity, producing an annual energy output of 380 GW·h.