Periyar (river)

Periyar (meaning: big river) is an river flowing in the state Tamil Nadu & Kerala, India, with a length of 244 km in Kerala. It is one of the few perennial rivers in the region and provides drinking water for several major towns. The Idukki Dam on the Periyar generates a significant proportion of Kerala's electrical power.

It originates from the Sivagiri peaks (1800m MSL) of Sundaramala in Tamil Nadu.. The total length is about 244 Kms with a catchment area of 5,398 Sq. Kms (5,284 Sq. km. in Kerala, 114 Sq. km. in Tamil Nadu). It flows northwards for 48 kms and at Thekkady joins the west-flowing Mullayar, which is a tributary of the periyar. The Mullaperiyar Dam is constructed at the confluence of both the rivers Periyar and Mullayar to create the Periyar lake and reservoir and the Periyar National Park.

From Periyar Thekkady lake and reservoir, water is diverted eastwards to Tamil Nadu via a tunnel enabling the water to join the Vaigai River. From Periyar Thekkady Reservoir, the Periyar river flows northwestward for 35 km through Vandiperiyar, Elappara and Aiyyappankoil to join 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.

Anamudi (2,695m) is the highest point of the Periyar basin.