Cauvery Basin: The Grand Anicut of Cholas

The Grand Anicut, though later rebuilt by the British, is believed to have been built in the mid to late Chola times. It is a vast construction for its time, spanning a thousand feet across the Cauvery and sixty feet wide. The Chola monarchs needed the dam to tackle the problem of using the flood waters of the cauvery for irrigation to create more consistent food and wealth. The Grand Anicut stands just after the Srirangam Island diverting water into a network of channels that feed the Cauvery delta to the east. This was part of an agrarian system that the Cholas founded, which remained largely unchanged till the nineteenth century, based on a skilful use of river channels, wells and reservoirs. British nineteenth century irrigation specialists wrote of the virtual completeness with which 'surface irregularities' had been used to hold water and found little need for the construction of new ones.

This irrigation technology was part of the system of authority and governance of their vast empire during the ninth to twelfth centuries. The Cholas controlled this system by granting water rights, just as they would land rights, to kinsmen, military chiefs, royal retainers, village officers and especially religious institutions. These rights were a way of renewing political alliances or securing military support and this created a system of control where areas governed themselves but would still remain faithful to the king. Broadly speaking this meant rich peasants dug wells, chiefs built tanks, and kings built large dams.