1. The name is interpreted as Thamiram (copper) Varuni (streams of river).
2. The water of this river gives a copper like appearance due to the presence of dissolved red soil.
3. The river originates from a peak in Pothigai hills on the Western Ghats above Papanasam in the Ambasamudram taluk, (only river originates in Tamil Nadu).
4. The origin of the river is associated with Sage Agasthiyar.
5. It courses through the districts of Tirunelveli and Thoothukudi.
6. It flows into Bay of Bengal near Punnaikayal in Thoothukudi district. Tributaries: Karaiyar, Servalar, Manimuthar, Gadananathi, Pachaiyar, Chittar and Ramanathi.
7. It is the only Perennial river of Tamil Nadu as it is fed by both the Southwest and Northeast monsoons.
