Origin The Thamirabarani River originates from the peak of the
Pothigai hills on the eastern slopes of the
Western Ghats at an elevation of above sea-level. The river is joined by its headwater tributaries Peyar, Ullar, Pambar before it flows into the Karaiyar Dam reservoir, where it meets Karaiyar. The river forms the Paanatheertham waterfalls, high, as it enters the Kariyar reservoir. Servalar joins the Thamirabarani before it enters into the
Papanasam lower reservoir, which was built for the Papanasam Hydroelectric station. The river descends down the mountains near Papanasam, where it forms the Kalyanatheertham falls and Agasthiar falls.
Course and tributaries The river flows on the plains eastwards from
Papanasam. The first tributary to join Thamirabarani in the plains is the
Manimuthar River, which originating from Manjolai hills and joins Thamirabarani near Aladiyoor village. The towns
Ambasamudram and
Kallidaikurichi are located respectively on the left and right banks of Thamiraparani, after which the river meets the tributary
Gadananathi River at Tiruppudaimaruthur. Before the Gadananathi's entry into the Thamirabarani, the
Gadananathi River is joined by the rivers Kallar, Karunaiyar and Veeranathi or Varahanathi which joins the river Gadananathi about north-east of Kila Ambur. The Gadananathi is fed by the
Jambunathi and
Ramanathi Rivers. The
Pachaiyar River which originates from the Kalakkadu reserve forests at about above sea level joins the Thamirabarani near Tharuvai village in Palayamkottai Taluk. The river bisects the twin cities
Tirunelveli and
Palayamkottai before meeting its major and affluent tributary Chithar (Chitranathi) which arises in the Kutralam hills and receives supply from the rivers Gundar, Hanumanathi and Karuppanathi(vairavangkulam kadayanallur) .The
Chittar River runs almost parallel to Thamirabarani till it joins the main river near Sivalaperi. Thamirabarani passes through the taluks of Tirunelveli and Palayamkottai of Tirunelveli district and
Srivaikundam and
Tiruchendur taluks of
Thoothukkudi district. ;List of major tributaries
Drain The river drains into
Gulf of Mannar near Punnaikayal in Tiruchendur taluk of
Tuticorin district. The river drains with its tributaries an area of about . As most of its extensive
catchment areas lie in the Western Ghats, the river enjoys the full benefit of both the monsoons, which make the river perennial. Since all its tributaries are arising from the Western ghats, the river is prone to heavy floods especially during the
northeast monsoon. In 1992, there was an unexpected flood in Thamirabarani, which claimed hundreds of lives as the dam water was let out so massively and suddenly that the river and its channels could not bear the excess water inflow. It flooded again in 2015 with water entering the Kurukuthurai Murugan Temple, In December 18,19 2023 due to Massive rain fall in River Catchment area this river flooded again it discharged Maximum n 4.5 lakh Cubic feet water on Bay of Bengal . flood occurs the City of Tirunelveli, Palayamkottai in Tirunelveli district and Eral, Athur of Thoothukudi district Worsley affected during this Flood. ==Irrigation==