New York, NY —

There are many great mysteries of a New York City childhood. How do birds get into subway stations—and can they leave? Who is Cotton Eye Joe and why do they sing about him at Yankees Stadium? And when do the spray showers in the playgrounds get turned on for the summer? WNYC’s Kate Hinds can’t help you with the first two, but she did find out when the spray showers go on.

REPORTER: It’s not pegged to Memorial Day. It’s not about the last day of school either. Nope, it’s not the summer solstice on June 21st. Give up? It’s entirely weather dependent. The spray showers in the playgrounds get turned on when it’s not raining and the temperature is generally predicted to reach 80 degrees—right about this week, as you may have noticed.

But before the spray showers get turned on, dozens of city Parks Department employees—like Plumber Glen Gunther—spend months getting the plumbing ready for the season.

GUNTHER: We grease things up, we lay out work, repipe, repipe a lot of stuff, a lot of stuff gets damaged during the course of the winter, and we just prep things for the initial turn on. I have all the tools in the truck for that. Spoons, big spoons. It’s hard work, but we do them one at a time.

REPORTER: Gunther’s part of a team in Brooklyn’s Prospect Park that works from April to June de-winterizing the outdoor water services.

GUNTHER: I tell you, the plumbing division for the Parks Department is kind of like the arteries— we’re the heart of it. I know you have electricians, you have carpenters, but the plumbing is always the main part.

REPORTER: Gunther and his assistant, city parks worker Mordechai Ben-Eli, are testing three large bronze frog sculptures that spout water. Job number one: locate the curb box, which in this case is not where one might think it is.

GUNTHER: These are curb box covers, even though we’re not at the curb, these are generally at the curb. This is a valve box and this is the cover. Hit it with the hammer. There you go. And it’s cast iron.

REPORTER: Once the cover is lifted, Gunther demonstrates a skill honed during 20 years on the job.

GUNTHER: Okay. This one—see, it’s all full of sand. What I have to do is… by feel. I’m not bragging, I keep my eyes closed.

REPORTER: He fits a six foot tall metal cock key into the valve and gives it a quarter-turn to the left. This is how the spray showers must be turned on—and off—each day.

GUNTHER: ( You ready?) Here come the frogs. (sound of shower)

REPORTER: Under Robert Moses, then Parks Commissioner, New York began building spray showers in the 1930s. The effects were immediate— and lifesaving, according to Adrian Benepe, current Parks Commissioner.

City Parks Workers Mordechai Ben-Eli and Glen Gunther after activating a dragon spray shower in Imagination Playground, Brooklyn Photo: Kate Hinds

BENEPE: Prior to 1934, over 500 people would drown every year swimming in the rivers and harbor waters of New York City—most of them kids, because there was no place else to go on a hot day, you’d go jump off the piers and swim. On average, two kids a day would drown.

REPORTER: Benepe says the subsequent drop in drowning deaths is directly attributable to providing children with safer ways to combat the summer heat.

Today there are almost 700 spray showers in playgrounds across the five boroughs. Al Simoncini, a supervisor in the Parks Department’s Brooklyn shop, explains that while the showers use a considerable amount of water, the city’s drought emergency of 2002 led to some changes.

SIMOCINI: When we were growing up, they would throw a ton of water, which was real nice—it was great. But most of the newer systems are very low flow, low gallons per hour, I mean typically the old systems would, you know, be 15 to 20 gallons a minute and the newer systems are anywheres from, you know, like 2 to 5 gallons a minute.

REPORTER: But until recently, the city could not recycle any of the tens of thousands of gallons of water that go down the drain when the spray showers are in use. Adrian Benepe.

BENEPE: So we created gray water recycling systems, where the water gets captured in holding tanks and then purified with an ozone treatment method and then is available for secondary uses, particularly for watering plants.

REPORTER: Although they’ve only installed these systems in a few playgrounds, there are plans in the works to for several dozen more.

As you can hear, Parks Department employees have most of the outside water features up and running—and just in time.

Six year old Katie Wilson is one of dozens of kids seeking relief at River Run Playground on Manhattan’s Upper West Side. The playground features a miniature Hudson River, which replicates the river’s path from its source in the Adirondacks down to New York Harbor.

WILSON: I’m filling up a bucket and I’m gonna pour it on my head.

Spray shower at River Run Playground in Riverside Park, Manhattan. Photo: Kate Hinds

REPORTER: The average observer might think she’s just having fun and staying cool. But to Adrian Benepe, her play may serve a larger purpose.

BENEPE: New York City is the great producer of Nobel laureates, way more than any other city, many of them grew up in these neighborhoods and went to public schools and I often wonder: Did somebody win a Nobel prize in sort of fluid dynamics or physics because as a child she or he, you know, played around with one of our spray showers?

For WNYC, I’m Kate Hinds.