Telangana Irrigation Minister T Harish Rao made the request in a letter to his Karnataka counterpart M B Patil.
"Drinking water is being supplied to these places through Puttamgandi (irrigation project) under the Nagarjunasagar (reservoir). Against the minimum draw-down level of 510 feet, the current level is 500.50 feet, and we would be barely able to sustain the supply without any inflows to Nagarjunasagar," Rao said in the letter, as per an official statement here.