The Kingdoms of the South (3rd BCE – 3rd CE)
Around 15 km from Tamil Nadu’s Tiruchirappalli and 45 km from the historic city of Thanjavur, you will find a dam on the Kaveri River that has the most fascinating story. The Kallanai or the Grand Anicut, as it was called, is one of the oldest irrigation works in the world. Said to be built by one of the early Chola kings, Karikala in the 1st-2nd CE, it has been in continuous use for almost 2,000 years.
But the dam (which started as an embankment) is famous not only for its antiquity; the Kallanai is quite an engineering marvel. It not only controlled the annual floods in the region, the irrigation works set in place to divert the flood waters through canals during the time of King Karikala transformed the once semi-arid region south of it into one of the most fertile stretches in the subcontinent. Ancient Sangam poetry celebrates Karikala’s success in transforming a wilderness (kattu) into a cultivable land (Nadu).