Ponnaiyar River

Chandapura, Anekal, Hosur, Bagalur and Chengam are the major industrial settlements on its banks.

[citation needed] The river originates in the Nandi Hills in the Chikkaballapura district of Karnataka and flows through Tamil Nadu before emptying into the Bay of Bengal.

It has a catchment area of 1,424 square miles (3,690 km2) located in Karnataka and Tamil Nadu states.

[2] A substantial part of Bangalore's sewage enters this river via Bellandur and Varthur Lakes and other channels.

Mentions of the river are found in Sangam and medieval (Tevaram - Bhakti cult era) literature, where it is depicted as rich with lush vegetation on its banks.