The waters of the Narmada are likely to prove a mirage for Rajasthan even as the authorities here have based their calculations on the river project for future water supply to Jaisalmer, Barmer and Jalore districts.WEhile the Chief Minister, Mr. Asok Gehlot, believes that Narmada waters would soon become a reality in the desert districts, the noted environmentalist, Ms. Medha Patkar, who spearheads the agitation against raising the height of the Narmada dam, is skeptical.