The river Tamiraparani is a symbol of Tamil culture. It is the main river of the district Tirunelveli. It is referred to in Tamil and Sanskrit literature of the earlier period, and as the Porunai nathi in Tamil literature. Saint Muthuswami Dikshitar, the great Carnatic music composer, an extensive traveler whose songs abound with geographic and iconographic references, sings in praise of the river Tamiraparani. To him the Goddess at Tirunelveli, is Hima-saila-sutaa, daughter of the mountain Hima, and suddha Tamraparni tata sthitaa while Vishnu in Kallidaikurichi Perumal Koil is bhangahara Tamraparni tirastha. According to Claudius Ptolemy's "Geography" Book VII chapter I. (2nd Century A.D.) Colche (Korkai) was situated (north of the estuary of the river Solen. Solen seems to be the Greek pronunciation of Sutha nadhi, another name of the river Tamiraparani as mentioned in Tirunelvelippuranam. This estuary may be located at Kayalpattinam where a drainage channel from Kadambakulam, enters the sea. This channel was once a big river fed by rainwater canals, and is also called Periyaru (Big river).
Thamiraparni has a large network of tributaries - Peyar, Ullar, Karaiyar, Servalar, Pampar, Manimuthar, Varahanathi, Ramanathi, Jambunathi, Gadananathi, Kallar, Karunaiyar, Pachaiyar, Chittar, Gundar, Aintharuviar, Hanumanathi, Karuppanathi and Aluthakanniar. Only two rivers of the Tirunelveli district - Nambiar and the Hanumanathi of Nanguneri taluk are not linked to Tamiraparani. (There are two Hanumanathis in the district).
There are many views on the meaning and origin of the name Thamiraparni. In his book, 'A History of Tinnevelly', the well known Tamil literary figure and missionary of nineteenth century, Bishop Caldwell residing at Idayankudi, a classmate in Britain of Lord Napier the then Governor of Madras (1866 - 1872), discusses the various interpretations of the word ‘Tamiraparani’. The meaning of the word Tamiraparani is sufficiently clear, Tamara means, red, parani means parana, a tree which has leaves, but why the river is named so is not known.
Another view is the name Tamiraparani originates form Tamiram (Copper) + Varuni (stream or river). They ascribe this to the origin of the river from red soil, giving the water a copper like appearance. The Greeks of the Ptolemy’s time refer to this river as Solen.
By naming this river Thamiraparni, tree with red leaves, a simile is drawn out between this river with a large number of tributaries to a tree with innumerable branches, reaching out widely the entire region.
As is the Indian tradition to associate various physical aspects to various Gods, His various incarnations or Saints, the Tirunelveli Sthalapurana associates the origin of the river with sage Agasthiyar. It states that when Agasthiyar was requested by Lord Siva to move to the South, Parvathi Devi, the divine consort of Siva filled the sage’s kamandalu (font meant to hold water for poojas) with the water from the Ganges and on his arrival at Pothigai, he released it and the water ran as Thamiraparni.
Originating at an altitude of 1725 m. above MSL at Periya Pothigai hill ranges, an integral hill track of Western Ghats, in Ambasamudram taluk, it traverse a length of about 125 km. passing through the taluks of Tirunelveli and Palayamkottai of Tirunelveli district and Srivaikundam and Tiruchendur taluks of Thoothukkudi district, joins the Gulf of Mannar of the Bay of Bengal at Punnaikayal in Tiruchendur taluk of Thoothukkudi district. This great river, like the Cavery, is fed by both the monsoons – the south west and the north eastern - and is seen in full spate twice a year if the monsoons do not fail.
In the Ghats, its chief tributaries are the Peyar, Ullar, Karaiyar, Servalar and the Pambar. The first tributary which enriches the water of the Tamiraparani in the plains on the right side is the Manimuthar. Then comes the Gadananathi, which joins the Tamiraparani at Tiruppudaimaruthur. Before the Gadananathi’s entry into the Tamiraparani, the Gadananadhi is joined by the rivers Kallar, Karunaiyar and Veeranathi or Varahanathi which joins the river Gadananathi about 1.5 km north-east of Kila Ambur. The river Pachaiyar is another tributary which joins the Tamiraparani near Tharuvai village in Palayamkottai Taluk. One of the important and affluent tributaries of the Tamiraparani is the Chithar or Chitranathi which arises in the Courtalam hills and receives supply from the rivers Gundar, Hanumanathi and Karuppanathi. The Chithar empities itself into the Tamiraparani in Sivalapperi Village.
The river drains with its tributaries an area of about 4400 sq. km. As most of its extensive catchments areas lay 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 North East monsoon.