Erattayar Dam

Nestled amidst the picturesque landscapes of Erattayar in the Idukki district of Kerala, the Erattayar Dam stands as a remarkable feat of engineering that has been serving a crucial role in the region since its opening in 1975. This gravity dam, owned by the Kerala State Electricity Board, primarily operates for power generation but plays a more intricate role in the region’s water management system.

Erattayar Dam: Harnessing Water’s Power and Control

The dam, with its towering foundation height of 19.81 meters and an impressive length of 146.3 meters, is an imposing structure that harnesses the might of the Perinjamkutty River, a tributary of the mighty Periyar. What sets it apart is its two Ogee-type spillways, equipped with two radial gates, which facilitate precise control over the water flow.

Functionally, the Erattayar Dam serves as a vital diversion dam to supply water to the nearby Idukki Dam. This water diversion is made possible via the 3.77-kilometer Anchuruli Tunnel, a critical component of the Idukki Hydroelectric Project-Stage III, designed for the Kallar-Erattayar diversion scheme. The dam also creates two forebays with storage capacities in the Kallar and Erattayar rivers, serving as strategic reservoirs for the region’s water needs.

Additionally, the Erattayar Dam plays a pivotal role in ensuring a consistent water supply to various taluks and regions downstream. This multifaceted structure has become an integral part of the local ecosystem, contributing to the region’s power generation and water management systems.