India, Aug. 3 -- The leaders on either side of the divide have changed and so have the eras, but the century-old dispute between Karnataka and Tamil Nadu over sharing the water of the Cauvery simmers. This week, a potential face-off between Karnataka chief minister DK Shivakumar and his Tamil Nadu counterpart C Joseph Vijay was averted after the latter agreed to postpone his visit to Bengaluru. Tensions have been rising between the two neighbours amid an indifferent monsoon - the monsoon was 19% below normal in Karnataka from June 1 to August 3 and 13% below normal in Tamil Nadu - and Vijay's government has approached the Supreme Court.

The immediate trigger for the bitterness appears to be developments on the Mekedatu reservoir project,...