When the thousands of water lorry drivers who shore up parched Chennai's overtaxed water delivery system went on strike for three days last month, to protest a ruling restricting their access to groundwater, a water crisis ensued.
Hotels and malls shut. Taps ran dry in residential districts of the city.
"My phone rang incessantly," remembers Sarvanan Parthasarthy, the owner of Jai water supply, one of the striking private water tanker firms.
"A resident called and even threatened suicide if I didn't send a water tanker. Water is like that. We can't live without it," he told the Thomson Reuters Foundation.
India is suffering "the worst water crisis in its history", according to a June report by government policy think tank NITI Aayog.
Worsening water shortages - for farmers, households and industry - threaten the lives and incomes of hundreds of millions of Indians, and the economic growth of the country, the report said.
An estimated 163 million people out of India's population of 1.3 billion - or more than one in 10 - lack access to clean water close to their home, according to a 2018 report by WaterAid, an international water charity.