In a year of drought, both Karnataka and Tamil Nadu, embroiled in dispute over sharing of Cauvery water, will have to agree to scale down each other's quantum of water requirement, Congress General Secretary Digvijaya Singh said on Saturday."So in a year of drought, both states have to agree to sort of scale down, the quantum of water availability for each state, so that process is on," said Digvijaya Singh, who is in-charge of party-ruled Karnataka."Unfortunately, we have had three consistent decisions by the honourable Supreme Court and a different bench has acted beyond the prayer. They have also ignored the recommendations of the supervisory committee set up by the Supreme Court to look into the release of water," he said, adding that the Karnataka government, following the unanimous resolution passed in the state assembly earlier this week, would challenge the apex court decision. "First charge of water resources is for drinking purpose. Whatever surplus is there, goes to agriculture for irrigation," he added.