Kallanai Dam - Trichy

It is uncommon to come across an engineering marvel dating back to ages. Fortunately for those in Trichy, there is such a marvel as a dam which is still functional efficiently. Built by the famous Chola King ‘Karikalan’ around the first century, Grand Anicut (‘Kallanai’ in the local parlance), is one of the oldest water regulating structures in the world. The idea behind the construction of the dam was to divert the river Kaveri to the districts which are located in the delta region thereby boosting irrigation. It is a massive structure constructed with uneven stones to a length of 329 metres and a width of 20 metres across the mainstream of the river Kaveri. It is a unique structure built just with large boulders brought over and sunk in the sand.

The dam was later re-modeled by the British during the 19th century. In the year 1804, Captain Caldwell, a military engineer, was appointed to promote irrigation in the delta region. After some research, he found out that only a small amount of water was left for irrigation as the maximum water went to Kollidam. Caldwell proposed to increase the height of 0.69 meter, which was taken as a solution to increase the capacity of the dam. The Rocks are directly placed in the path of the River Kaveri, which acts as an external thrust to maintain stability. The sand bed gives great strength and durability to the structure. This will show the work and knowledge of the ancestors. It is still in an excellent condition and is often frequented by locals at the time it is to its capacity.