The Idamalayar Dam is located on the Idamalayar River, a tributary of the Periyar River in Kerala.
The dam is located from Ernakulam in Ernakulam district and from the Bhoothathankettu dam (literal meaning in Malayalam language: "monster dam") on the Periyar River, which takes its name from local myths attributing its construction to demons who built it with the intention of submerging Thrikkariyoor temple [REF].