The Palar (Tamil: பாலாறு pālāṟu [ˈpaːlaːɾu], literally "milk river") is a river of southern India. It rises in the Nandi Hills in Chikkaballapura district of Karnataka state, and flows 93 kilometres (58 mi) in Karnataka, 33 kilometres (21 mi) in Andhra Pradesh and 222 kilometres (138 mi) in Tamil Nadu before reaching its confluence into the Bay of Bengal at Vayalur about 75 kilometres (47 mi) south of Chennai. It flows as an underground river for a long distance only to emerge near Bethamangala town, from where, gathering water and speed, it flows eastward down the Deccan Plateau. The Towns of Bethamangala, Santhipuram, Kuppam, Mottur, Ramanaickenpet, Vaniyambadi, Ambur, Melpatti, Gudiyatham, Pallikonda, Anpoondi, Melmonavoor, Vellore, Katpadi, Melvisharam, Arcot, Ranipet, Walajapet, Kanchipuram, Walajabad, Chengalpattu, Kalpakkam, and Lattur are located on the banks of the Palar River. Of the seven tributaries, the chief tributary is the Cheyyar River.
Palar river water from Palar anicut is diverted to the Poondi reservoir located in the Kosasthalaiyar River basin and to Chembarambakkam Lake located in the Adayar River basin. These two reservoirs are major water supply points to Chennai city. After commissioning of the Telugu Ganga project to supply nearly 1,000,000,000 litres (260,000,000 US gal) per day of Krishna River water to the Chennai city, the dependence on Palar river water has reduced drastically.
