If the rain comes | They run and hide their heads Brooklyn flooded on Friday. Again. Subway lines shut down as water poured off streets, down stairways and into stations. A niece reported she had to take cabs into the city for work and the basement entry was knee-deep. Nancy Walecki wrote last week at The Atlantic: New York City’s sewer system is built for the rain of the past—when a notable storm might have meant 1.75 inches of water an hour. It wasn’t built to handle the rainfall from Hurricane Irene, Hurricane Sandy, or, more recently, Hurricane Ida—which dumped 3.15 inches an hour on Central Park. And it wasn’t built to handle the kind of extreme rainfall that is becoming routine: The city flooded last December, last April, and last July—an unusual seasonal span. “We now have in New York something much more like a tropical-rainfall pattern,” Rohit Aggarwala, New York City’s environmental-protection commissioner, said yesterday at The Atlantic Festival. “And it happens over and over again.” It happened today. Less than 24 hours after Aggarwala’s statements, rain arrived in New York City—the kind that sends waterfalls through Brooklyn subway ceilings, dangerously floods basements, and floats cars on the road like rubber ducks. Mayor Eric Adams said earlier today that the city could receive up to eight inches of rain today; parts of Brooklyn saw a month’s worth of rain in just three hours. New York State Governor Kathy Hochul has declared a state of emergency, and New York City residents received emergency alerts cautioning…