"A drop of water conserved, a drop of drinking water earned."
Yesssssss!
Thinking of that, how many inches of rainwater fell on NYC last year?

Huh. That's funny, when we add it up, we get 47.14 inches. But no matter, the thought is: Plenty of rainwater falls on NYC per year. Enough so we could all have plenty to drink and still be able to shower and bathe without feeling guilty.
So, how much rainwater is being captured, filtered, and utilized?
Ten percent? One percent? 0.1 percent? Whatever the answer is, we need more water catchment and storage.
Instead of simply shunting the rainwater into the sewer, each building in NYC should be treating it like the resource it is. Puffing up like a cactus when the rain falls, and then storing it for when we need it. And because rain tends to fall from above, you can use gravity to filter it on its way down to people's apartments and offices.
Rainwater is some precious stuff, yo!
Here's a great youtube viddy about how plants utilize water and sunlight:
Good on you, P.J.! Thanks for the great New Superstition!