Kerala is worshiped with its water bodies. There are 44 rivers in kerala and most of them are originates from the deep forests of western ghat. However rivers in kerala are comparatively small than other Indian rivers. The Government of Kerala declared the streams which has a length of 15+ km as river, and there are many other streams out of this norms. From the age of ancient history to tens of years ago these revers were the most important way of transportation in the state. Periyar is longest river of Kerala (244 km)where most of our hydro-electric projects are situated. Just have an overview among them:
Periyar, as its name, is the longest river in Kerala which originates from the sivagiri hills of western ghats and flows through the districts of Idukki and Ernakulam. Flowing through thick forests, it joins with mullayar, at thekkady and gets a name mullpperiyar, where the 100+ years old dam situated which is the cause of dispute between Kerala and Tamilnadu. Vast amount of the state's electricity needs are depends upon the hydroelectric projects situated in periyar. The Idukki arch dam, one of the largest of its kind in the world, is in the periyar river in Idukki. The famous Hindu festival Aluva sivarathri is conducted in the shore of periyar at Aluva, Ernakulam district. Muthirappuzha , cheruthoni, mullayar, idamalayar, kattappana, Perinjamkutty are its major tributaries.
This is the second longest river in Kerala, got her birth at Anamalai hills of western ghats, flows towards west by its 209 km of length throught the districts of Palakkad, Thrissur and Malappuram. On its way the main tributaries named Thoothappuzha, Kalpathi puzha, Gayathrippuzha, Kannadippuzha are joins with it and ends in the Arabian sea at Ponnani. There are five bathing sectors named Thirunavaya, Thiruvilwamala, Thiruvegappura, Thrithala, and Thirumittakkodu in the banks of Nila, were Pithru tharppana (feeding for the ancients, which is a custom of Keralites)are held. The historical festival of Mamanka were held at Thirunavaya. The Malampuzha dam was situated in Palakkad district constructed for irrigation purpose.