Built around 2,000 years ago across the Cauveri River in Tiruchirapalli District of Tamil Nadu, the Kallanai Dam is still in excellent condition and used as a major irrigation dam even now. The dam has been inspiration to many modern day dams too due to amazing engineering. Read more to know about this unique example of the amazing architecture and engineering of ancient India.
When I was a kid, water always amused me. I would wonder where it came from, where it went and how did it first come into existence and found its way to our house taps.
Kallanai Dam, also known as the Grand Anicut, is one of the oldest water-regulator structures in the world which is still in use.
Built around 2,000 years ago across the Kaveri River in Tiruchirapalli District, Tamil Nadu, by Karikala Chola, the dam was constructed to divert the river to the delta districts thereby boosting irrigation and avoiding loss of crops due to floods.
The dam though very old has a strong foundation and a solid structure. It is still in excellent condition and is used as a major irrigation dam in Tamil Nadu. The dam has also been an inspiration for many recent modern day dams due to its amazing engineering. Due to its impressive architecture, the dam attracts a lot of tourists every year.
The unique structure of the Kallanai dam involves large stones sunk in the Cauvery river to divert the water flow to the fertile delta. The main function of the dam was to retain the water supply in the Cauvery and flow the surplus into Coleroon through the Ullar river. The dam was re-modeled by the British during the 19th century.
In 1804, Captain Caldwell, a military engineer was appointed to promote the irrigation in the delta region. After some study he found out that only a small amount of water was left for irrigation as the maximum water went to Kollidam. Caldwell proposed a solution by raising the dam. Hence, the dam stones were raised to a height of 0.69 meter, which increased the capacity of the dam.
It is believed that floods to an extent of about 5260 cumecs (1,86,000 cusecs) have been discharged through this anicut with minimal or no damage. (Source)
The dam is made of unhewn stone and is 1,080 feet long and 60 feet wide, across the main stream of the Cauvery. The area is irrigated by the ancient irrigation network of which the dam was the centrepiece, covering about 69,000 acres. By the early 20th century, the irrigated area had increased to about 1,000,000 acres. (Source)
The Lower Anicut built by Sir Arthur Cotton in 19th century AD across Coleroon, the major tributary of Cauvery, is said to be a replicated structure of Kallanai.
How to reach there?
Kallanai dam is located 19 kms. from Tiruchirappalli, and the nearest airport is the Tiruchirapalli airport, about 13 kms. away from the dam site. The nearest railway station to Kallanai Dam is Lalgudi railway station Junction which is 4 kms. away from the Kallanai Dam.