The main rivers of Tamil Nadu originate in the Western Ghats and flow eastward. All of them are rain fed. The state has a few perennial rivers, apart from Kaveri. They are Palar, Cheyyar, Ponniyar, Meyar, Bhawani, Amaravati, Vaigai, Chittar and Tamaraparani. The perennial rivers are the Vellar, Noyal, Suruli, Gundar, Vaipar, Valparai and Varshali. Kaveri is the largest river of the state with its length of 760 kilometers .