Kallanai (also known as the Grand Anicut) is an ancient dam, which is built (in running water) across the Kaveri river in Thanjavur District in the state of Tamil Nadu in India. Located at a distance of 15 km from Tiruchirappalli, the dam was originally constructed by the Chola king Karikalan in . It is located on Kaveri river approximately 20 KM from Trichy city, the dam comes under Thanjavur district. It is the fourth-oldest water-diversion or water-regulator structures in the world and the oldest in India which is still in use.
The dam was originally built by King Karikalan of the Chola Dynasty in . It is located on the River in Tiruchirapalli District, approximately 20km from the city of Tiruchirapalli. The idea behind the construction of the dam was to divert the river to the delta districts thereby boosting irrigation. The dam was re-modeled by the British during the 19th century. In 1804, Captain Caldwell, a military engineer, was appointed by the British to make a study on the Kaveri river and promote irrigation for the delta region. He found that a large amount of water passed onto the Kollidam leaving behind a small volume for irrigation purposes. Caldwell initially proposed a solution by raising the dam and hence raised the dam stones to a height of 69cm, thus increasing the capacity of the dam. Following this, Major Sim proposed the idea of undersluices across the river with outlets leading to the Kollidam River (Coleroon) thus preventing formation of silt. The Lower Anaicut built by Sir Arthur Cotton in the 19th century CE across Coleroon, the major tributary of Cauvery, is said to be a replicated structure of Kallanai.
The Kaveri river splits into two at a point 20mi west of Kallanai. The two rivers form the island of Srirangam before joining at Kallanai. The northern channel is called the Kollidam (Coleroon); the other retains the name Kaveri, and empties into the Bay of Bengal at Poompuhar. On the seaward face of its delta are the seaports of Nagapattinam and Karaikal.
The purpose of the Kallanai was to divert the waters of the Kaveri across the fertile delta region for irrigation via canals and to its northern delta branch Kollidam/Coleroon. Downstream of the barrage, the river Kaveri splits into four streams known as Kollidam Aru, Kaveri, Vennaru and Puthu Aru. However, the flood waters can be allowed, by opening the barrage/anaicut gates, to pass through the other three delta branches also to join the sea. It is constructed from unhewn stone spanning the Kaveri and is 329m long, 20m wide and 5.4m high. The dam is still in excellent condition, and supplied a model to later engineers, including Sir Arthur Cotton's 19th-century dam across the Kollidam, the major tributary of the Kaveri. The area irrigated by the ancient irrigation network is about 69000acre. By the early 20th century, the irrigated area had been increased to about one million acres (400,000 ha).
The delta farmers of Tamil Nadu have demanded that the Tamil Nadu government honour Karikala Cholan, who built the Kallanai.
Sketch of Comprehensive Kaveri-Kallanai Project
Second Tamil Sangam that was in existence about 2000 years ago, Chola King, Karikal Peruvalathan, was ruling the Chola Kingdom with "Uraiyur" as capital. King Karikalan’s father was King Uruva Paharere Ilamcetchenni. In spite of being one of the glorious kings, King Karikalan is well known till this day for his monumental undertaking and completion of "Kaveri river –Kallanai dam (Grand Anicut) Irrigation project" that is fully functional till this day.
River Kaveri is the greatest river of Chola Kingdom (Tamil Nadu). River Kaveri originates in Coorg, part of western ghat, the present Karnataka State. It flows towards east to Tamil Nadu profoundly spilling its richness on both the states before merging into Bay of Bengal. King Karikalan during his tenure as the King of Chola Kingdom observed that the River Kaveri with all its richness merged into Bay of Bengal without its richness being fully utilized, for agriculture and fertility of the lands. As a King, this observation firmly anchored his mind, that motivated him to research and learn "River Pahruliaaru Irrigation Distribution System", that existed in the ancient "Lemuria Continent" (as called Kumari Kandam in Sangam literatures-- Picture 1), implemented by his ancestral "Pandiya dynasty". This River Pahuruli Irrigation system was washed away by the deluge of the first occurred tsunami of ancient world, leaving some of its residuals at the furthest southern end of old Tamil Nadu (Thamilagham). These evidences along with his own intellect motivated him to draw a comprehensive and unparalleled "Kaveri-Kallanai Project" during his reign-the fifth and the foremost economical irrigation project of the ancient world.
It would not be an overstatement if it was said that the "Kallanai (Grand Anaicut)", implemented by Chola King Karikalan with his genuine wit and technological skill was not only the greatest and superb of its kind of the then world, but also of our present world that we consider as "technically advanced". Kallanai (grand anicut) clearly signifies and glorifies King Karikalan’s irrigational expertise. The present day irrigation technologists had further expressed their surprise in King Karikalan’s brilliant irrigation technology that was similar to that of present day technology. Upon completion, King Karikalan’s Kallanai (grand anicut) project brought forth unimaginable and unparalleled extensive cultivable fields (approximately 69,000 acres) under flow irrigation. It is proclaimed to the world that from King Karikalan’s time to this date, though innumerable irrigation projects throughout the world had been implemented, taking much precaution on economic side, no project had attained such a cost-benefit ratio, excelling that of "Kaveri-Kallanai Project" implemented by King Karikalan.
Millions of people visit "Kallanai", to admire the irrigation project on ground and its new Kaveri Rivers-"present Kaveri" and "Vennaru", that irrigate lakhs of acres of land this day. While I was an Executive Engineer in the department of P.W.D, I had an opportunity to visit Kallanai in 1980 as one of the visitors among thousands. During that visit I heard people calling the "new Kaveri River", as "original Kaveri River" and the "original Kaveri River", downstream from "Mellanai" with its new name, "Kollidam River. I strongly felt that this was a total mis-conception because Karikalan’s comprehensive Kaveri River -- Kallanai Dam project’s super expertise had not been fully conceived and understood and their attention was simply focused on the surprising Kallanai dam that withstood 2000 years. This planted "a seed of research" in my mind that started to materialize in the later years after making several more visits to Kallanai and studying its technical aspects and working pattern on ground.
My vast experience along with my technical knowledge as an Irrigation and Civil Engineer, helped me to gather more of King Karikalan’s superb and valuable engineering brilliance, far away from the present day’s saying of, "Karikalan constructed Kallanai across the river Kaveri", In my observation and analysis I felt that Kallanai being only a surplus weir, constructed on the right bank of the diverted Kaveri river, and calling it as a Dam, did not sit in my mind very well. I strongly felt that there had to be a "missing piece" to the present day’s saying, "Karikalan constructed Kallanai", that must have remained unnoticed and in-conceived for well over two (2) millenniums. After through analysis of all the technical details and research of the ancient Tamil literature, this contemporary and hidden concept had been unearthed by me under the incitement of my specialty to bring out the everlasting wit and amazing technical expertise of King Karikalan and through which to glorify and salute his soul.
I feel proud to bring this treasure of marvelous engineering skill, domiciled with King Karikalan, with my civil and irrigation engineering background knowledge, superceding the earlier saying of, "Karikalan constructed Kallanai across the River Kaveri", with the following proposal;
1. RIVERS AT KOLLIDAM-KALLANAI
A comprehensive sketch of "Kaveri-Kallanai Project" (Picture 4) as observed and prepared by me with my technical knowledge is detailed above.
According to my illustration of the present "Kaveri-Kallanai Project", as is, the Original River Kaveri that is branched off at Mellanai from the present Kollidam River, is only a high level canal, now being called as River Kaveri. Present "Kollidam River", from Mellanai, which in reality is the continuation of the "Original River Kaveri", since it possesses entire characteristics of a naturally formed River. This New Kaveri River water is carried up to a point where it is further branched off into "new Kaveri River" and "Vennaru River". However, On the immediate upstream of this diversion and on the left bank of the "new Kaveri River", Kallanai was constructed by King Karikalan in order to drain the excessive flood water during the monsoon season over its surplus weir. The water thus drained is subsequently merged back to the "present Kollidam River" (which in fact should have been the "Original Kaveri River"), through another canal called "Ullaru".
The most important fact that I found at the outset was that the "new Kaveri River" from Mellanai to Bay of Bengal DOES not possess the basic characteristics of a Naturally formed River because of the following reasons;
1. Any natural river should begin with a narrow width at the head reach and flowing downstream making a wider width.
2. Natural rivers generally would make their own course by themselves cutting the terrain to the required width and slope and would run freely till they merge in to the sea.
3. A natural river would not irrigate fields through direct sluices in its entire run.
Therefore in my opinion beyond doubt, that the entire reach of the "new Kaveri River" from "Mellanai" to Bay of Bengal is simply an EXCAVATED CANAL not A NATURAL RIVER, although it has been called as "Kaveri River" in these past two (2) millenniums.
On the other hand "Kollidam River" from "Mellanai" possesses sound characteristics of a Natural River from its start to the end. Therefore I feel that the "present Kollidam River" should have been the continuation of the original river Kaveri from Coorg to Bay of Bengal via Mellanai. Therefore this has to be construed as continuation of the "original River Kaveri".
These concluded facts about the nature of the rivers made me to analyze the entire "Kaveri-Kallanai Project" further, from a different perspective as below. I am confident that this new concept of mine would open windows for further investigation and research on this project.
2. TECHNICAL CONCEPT OFsdfs KAVERY-KALLANAI PROJECT-My view as an Author
The completed project asserts the following:
At the outset a separate river like canal was branched off from the existing Mellanai, sixteen (16) kilometers upstream of Uraiyur, the then capital of the King Karikalan and now Thiruchirapalli city, and thirty (30) kilometers upstream of the existing Kallanai, was excavated with a raised bed level at its head and taken through a higher contour up to Kallanai point. The original River Kaveri while flowing from its origin, Coorg to the Bay of Bengal was blocked at Mellanai, by means of KORAMBU, made up of mud with reinforcement of small branches of trees, plants, hays and haystacks, a device for blocking the flow of water. The water level thus raised in the original River Kaveri was diverted to the newly excavated high level branch canal and carried up to Kallanai point. (However the newly excavated river like canal branching off at Mellanai, had been identified as river Kaveri, even today, in spite the fact it was an excavated high level canal specially designed by the King Karikalan depicting his worshipful engineering skill of all times!. The water thus carried up to Kallanai was again redistributed into the two separate canals namely "Kaveri River" and "Vennar River" for irrigating lower down fields.
Had King Karikalan completed the project at that posture, the engineering expertise domiciled within him might have either been faded away or his glory could have disappeared from the history and the Tamil Sangam literatures. Further the entire project might have gone under the process of silting and would have become obsolete. However, King Karikalan’s master mind put him into action. As a result, the surplus weir, i.e. Kallanai on the left bank of the excavated high level branch canal, "Kaveri River as it is now called, was constructed with TWO (2) purposes in mind;
1. To raise the water level of the "newly excavated high level canal (Kaveri River)" to the designed depth of the two downstream canals, "new Kaveri River" and "Vennar River"..
2. In order to surplus the extra water during the seasonal floods carried by the "newly excavated high level canal (Kaveri River)" back into the "original Kaveri River", or "Kollidam River", the monumental Kallanai was constructed out of the outburst of super technological expertise of the King Karikalan.
In my opinion, it is these two important features formed way to control everlasting quantity of flow into these two canals and ultimately engraved Chola King Karikalan in the history and Tamil Sangam Literary works with special distinction.
While we go through the Sangam literary works such as Pattinappalai, Puranaanooru and Porunar Aatruppadai, we find additional facts depicting various schemes implemented by the King Karikalan and their benefits derived such as;
1. Reclamation of vast area of forest lands for befitting them to receive the project water for cultivation ("kaadu kondru naadakki"-Pattinappalai 283)
2. More facts of formation of irrigation tanks to let the project water into them are also found. ("kulam thottu valam perukkiyon"-Pattinappalai 284)
3. Enormous yields of this project were so abundant and beneficiary which induced the Sangam Tamil Poets to write and sing in fabulous style. ("Spilled over paddy grains themselves accumulated during harvests would suffice to feed the entire Kingdom of King Karikalan-Porunar Aatruppadai-special poem)
The above research oriented narration of the "Kaveri-Kallanai Project" was not for blunting the age long misconception of the project but to further publicize to the present world about the implementation of a comprehensive, superb and unparalleled irrigation project, the foremost and the first of its kind in the then world, by the King Karikalan, who seemed to had adopted a technology of present age, on those days itself. It has to be further mentioned that these narrations would bring honor and glory to the Chola King Karikalan and would make those who either read this essay or witness the irrigation project that is in sound existence well over two (2) millennium to salute the King Karikalan.
Thanjavur Lokshabha Member of Parliament Sh. K. PARASURAMAN B. Sc. M.P. successfully raised his voice regarding importance of renovation of this age old irrigation system and accordingly “Improvements and Rehabilitation of Irrigation Systems in Cauvery Basin for Efficient Irrigation Management” at an estimated cost of Rs 11420 Crores was proposed to Ministry of Water Resources, Govt. Of India
First Phase of this project “Extension, Renovation and Modernisation of Grand Anicut Canal Sub basin of Cauvery Basin in Tamil Nadu” was approved by the Technical Advisory Committee of Ministry of Water Resources, River Development and Ganga Rejuvenation on 30.9.2016 for an amount of Rs 2298.75 Crores.
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