CHENNAI, India — When the water’s gone, you bathe in what drips out of the air-conditioner. You no longer allow yourself the luxury of an evening shower at the end of a steamy summer’s day. You sprint down two flights of stairs with plastic pots as soon as a neighbor tells you the water tanker is coming.

Every day, 15,000 tankers ferry water from the countryside into the city. Everywhere you look, rows of bright neon plastic water pots are lined up along the lanes, waiting.

This is life in Chennai, a city of nearly five million on India’s southeastern coast.