The irrigation system around Kuruvithurai near Sholavandan is a majestic model worth emulation. For centuries, it has ensured an eco-friendly water management and equitable distribution, besides preventing wasteful runoff into sea. If the Delta region can take pride in Karikala Chola’s Kallanai, an abridged version exists along the Vaigai near Kuruvithurai.
This structure, which forms an arc across the river at the place where it takes a detour, is a sight to behold. It allows diversion of excess flow in the river to the adjacent Thenkarai channel that empties into Thenkarai tank constructed by Senthan Sezhiyan (620-650 AD). The origin of this ‘Kallanai’ is not known, but from the stone inscription found at Chithra Ratha Vallabha Perumal Temple at Kuruvithurai, it is learnt that Parakrama Pandian (1097-1104 AD) renovated the check dam. He converted the brick and mortar structure into a stone barrage, which has withstood the test of time. A concrete crest was added to it by the British. The concrete layer shows signs of wear and tear but the stone structure remains intact.
Water management and conservation was the foremost duty of Pandya kings, who created waterbodies all over their territory.
Even poets eulogised kings on the basis of their contribution to water conservation, says writer B. Thirumalai in his book Neermelanmayai Thedi, citing several examples. G. Balaji, conservation architect, who teaches at Thiagarajar College of Engineering, describes ‘Kallanai,’ which is also referred to as Chittanai, as a water engineering feat. This “harmless, river-friendly structure” can be used in any river and that is why the British did not demolish it but only strengthened it. The Pandya kings did not want to control the river but tame it.
No siltation
Explaining the advantages of the Kuruvithurai check dam, Mr. Balaji says its location and shape prevent siltation and allow the structure to facilitate sand filtration. Instead of getting trapped, sand is conveyed back to the river. Against the perpendicular shape of modern dams, which results in high pressure on the structure, this arc barrage does not experience significant pressure. The kings also planted trees on the banks as flood barrier to prevent soil erosion. “We do not find trees around modern dams,” Mr. Balaji says.
He feels the random rubble masonry adopted in the Kuruvithurai structure is ideal for even modern day check dams in place of concrete, which absorbs heat and hence does not facilitate growth of micro organisms.
Recalling the references in post-Sangam literature and inscriptions about creation of waterbodies and construction of water management structures in the Pandya kingdom, V. Vedachalam, senior epigraphist, says the structures were planned in such a way not to affect the rights of lower riparian areas. The earliest archaeological evidence on water management system of south Tamil Nadu was found along the Vaigai near Kuruvikkaran Salai in the form of a stone inscription. It says that Arikesari Pandian cut a canal south of the river to convey surplus water. The inscription is displayed at the Thousand Pillar Hall of Meenakshi Sundareswarar Temple.
Karsirai
Check dams constructed by Pandya kings were referred to as karsirai (stone prison), as they were meant to trap water to regulate flow in the river. The check dams constructed in the Vaigai, Tamirabharani, Mullai and Suruli had a uniform height and diverted water to a series of tanks. They were named after the kings who constructed them. “Check dams, by nature, will not have any adverse impact on environment or people and water can be stored in them for local use, instead of letting the surplus flow into sea,” says Mr. Vedachalam.
A palm leaf inscription found at Thenur near Sholavandan classifies check dams into temporary and permanent ones. Since temporary check dams were built with logs and other available materials and dismantled after use, they ensured that there were no disputes in water sharing.
Renovation was carried out by the British on the Kuruvithural check dam and a regulator constructed along the Thenkarai channel in 1819. Today, a concrete structure has come up to reinforce the bank.
For people like S. Muthupandi, a resident of nearby hamlet Chittanai, the historical significance of the structure is not known. There is not even a signboard to guide the visitor. Mr. Veadachalam insists that apart from palaces and ancient structures, water management structures such as Kuruvithurai check dam should also be declared protected monuments.
He also calls for revival of traditional water management practices to prevent harm to man and environment.
