Mullai Periyar Dam and River

The name is derived from a portmanteau of Mullaiyar and Periyar. As the dam is located at the confluence of the Mullayar and Periyar Rivers, the river and the dam came to be called Mullaperiyar.

Periyar river originates in the Sivagiri Hills of the Western Ghats in Kerala, flows northwards and at Thekkady joins the west-flowing Mullaiyar, also originating in the Western Ghats in Kerala. The Mullaperiyar dam is constructed at the confluence of both the rivers Periyar and Mullaiyar to create the Periyar reservoir. From Periyar Thekkady reservoir, water is diverted eastwards to Tamilnadu via a tunnel enabling the water to join the Vaigai River. From Periyar Thekkady Reservoir, the Periyar river flows northwestward into the Idukki reservoir formed by the Idukki, Cheruthoni and Kulamavu dams. From Idukki reservoir, Periyar river flows northwestwards and then westward to join the Arabian sea at Munambam near Kodungallur and the Vembanad lake at Kochi.