The Periyar River is the second longest river in the state of Kerala, India, with a length of 244 Kms. The river is also known as The lifeline of Kerala as it is one of the few perennial rivers of Kerala. It provides drinking water for major towns.
The Idukki Dam has been built across the river and generates a significant proportion of electrical power for the state. This is a concrete, double curvature parabolic, thin arc dam.