Mumbai, July 31 -- Bihar's capital Patna went under this week. Water entered the city's biggest government hospitals, low-lying residential neighbourhoods adjoining the Sarayu river, and reportedly even the state Assembly and deputy chief minister's home.

This isn't a malaise unique to the east Indian state.

A thousand kilometres away to the north, in the national capital New Delhi, iconic commercial hub Connaught Place was submerged after rain lashed the city. Last week, swanky areas in Gurugram were flooded, including Golf Course Extension Road, where homes are sold for tens of crores.

In the west, parts of Mumbai were submerged, from the perennially troubled Andheri subway to parts of the swanky BKC office district, where brands suc...