India, June 9 -- With 636 flats, Challengers Cooperative Housing Society in Kandivali East is facing a twin crisis of tanker scarcity and soaring costs. The society requires six lakh litres of water daily, but BMC supply has fallen sharply while borewell output has dropped from 1.5 lakh litres to barely 50,000-60,000 litres a day. Tanker rates have jumped from Rs.1,000 to Rs.2,500, and despite ordering 20 tankers, the society received only 7-10. . "We ordered 20 tankers, but barely got half," said secretary B Sebastian, secretary, Challengers Cooperative Housing Society....