Bhavani River is a major river in Kongu Nadu region of Tamil Nadu, India. It is the second longest river in Tamil Nadu. This river is a major tributary of the Kaveri River. Bhavani river originates(starts) from Nilgiri hills of the Western Ghats. Bhavani enters the Silent Valley National Park in Kerala. It flows back towards Tamil Nadu. The Bhavani is a long perennial(everlasting) river. The river drains an area of spread over Tamil Nadu (87%), Kerala (9%) and Karnataka (4%). About 90 per cent of the river's water is used for agriculture irrigation.