I would also like the experts to throw some light on the irrigation systems prevalent in South India, especially in Kerala till the middle of this century, where system of open channels linking ponds were prevelant. Ponds again were small types for domestic use and bigger ones for agriculture in addition to deep wells for drinking water and the entire system was integrated part of the village life which appears common with what existed in Harappa and IVC.
Submitted by Prakash Pk

Iravatham Mahadevan
I am not aware of any studies directly connecting the irrigation systems of the Indus civilisation with those in South India.