President K.R. Narayanan on Saturday said India is facing an "acute water crisis" with some estimates showing that almost the entire economic growth may be wiped out by the health costs of water pollution. Inaugurating a three-day national conference on "The Potential of Water Harvesting" organised by the Centre for Science and Environment the president said, leading experts have warned that the world is heading towards "a water shock" which might dwarf the oil crisis.