At the time Egypt’s pyramids were being constructed, one of the cradles of global civilization grew up in the Indus Valley around the borders of what are today Pakistan and India. Its grid-planned cities produced sewage networks, delicate artworks and a yet undeciphered writing system. Then a 900-year drought emptied its urban areas and sent its population back to a simpler, poorer village life on the plains of the Ganges.

Something grimly similar is happening now.

Tech professionals are leaving India’s IT hub of Bengaluru amid an intensifying drought that has gripped the city as it sweats through another torrid pre-monsoon season, the Deccan Herald reported last month. More than half of the wells the city depends on for groundwater have dried up after failed rains last year, leaving businesses and citizens dependent on trucked-in water tankers.