Gadananathi originates from the eastern slopes of the Western Ghats, at an altitude of about 1700 m above sea level, in Ambasamudram taluk, Tamil Nadu. It is replenished by the rivulets Pampar, Kallar and Iluppaiyar, which combines with it at the Sivasailam village. After the conflux, the river flows downstream for another 10 km before joining with
Ramanathi near the Kila Ambur village. It finally plunges in to the Tamiraparani.
The Arasapattu, Alwarkurichi Thenkal, Manjapalli , Kakkavallur and Kangeyan are some major dams across the Gadananathi.