Prime Minister A B Vajpayee will inaugurate the Tirumala water supply scheme on the Tirumala Hills on Wednesday . The scheme involves pumping of Kalyani waters to Tirumala. The additional source of Kalyani waters to the hill shrine would be a boon to the water-starved pilgrims. Though the project of laying pipelines between Kalyani reservoir and Tirumala Hills was mooted in the early 80s, the project was dogged by delay.