Bhavani is an Indian river which flows through the states of Kerala and Tamil Nadu. It originates in the Nilgiris in the Western Ghats in Tamil Nadu, and flows westwards into Kerala for some distance, before turning east, and flowing back towards Tamil Nadu. It stretches for , and joins the Kaveri at Kooduthurai. The river basin covers an area of across three districts in Tamil Nadu. The major tributaries include the Moyar, and Siruvani Rivers. There are multiple dams across the river, including the Upper Bhavani, Bhavanisagar dam, and Kodiveri dam.
Hydrography
thumb|upright=0.85|left|The confluence of the Bhavani and [[Kaveri rivers at Kooduthurai]]
The Bhavani is a long perennial river fed by monsoons. The river originates at an altitude of in the Billimala range of the Nilgiris in the Western Ghats in Tamil Nadu. It flows westwards towards the Silent Valley National Park in Kerala, before later turning eastwards and flowing through the Attappadi valley in Palakkad district. The river basin covers an area of . Various rivulets and tributaries join the Bhavani river during its course. Major tributaries include the Moyar, and Siruvani Rivers. Bhavani is one of the major tributaries of the Kaveri, which it joins at the Kooduthurai near Bhavani.
Industrial, municipal and agricultural pollution of the river results in poor water quality and negative impacts on the health of people, plants and animals dependent on the river water.
Dams and canals
In Tamil Nadu, the Upper Bhavani dam is constructed close to the source of the Bhavani River in Nilgiris, and the Bhavanisagar Dam in the lower reaches of the river in the plains. After multiple proposals since the early 19th century, the upper and lower Bhavani projects were implemented in the mid 20th century. There are multiple minor check dams and irrigation canals constructed across the river in Kerala, largely constructed in the 21st century. The dam is one of the largest earthen dams in the world. The dam is situated some west of Sathyamangalam. The Lower Bhavani Project was the first major irrigation project initiated in independent India in 1948. The dam was completed in 1955 at a cost of and was opened in 1956. The dam was constructed in the 17th century by Maharaja of Mysore. The dam feeds the Arakkankottai and Thadappalli canals constructed for irrigation. The project, including construction of the dam and canal, started in 1271 and was completed in 1283. It was constructed by Kongu chieftain Kalingarayan.