The Hunt for Brooklyn's Hidden Creeks

Citizen scientists are like Dr. Livingstones venturing into the past, seeking the source of the Gowanus canal.

Aug 29 2014, 10:00am

Brooklyn's Prospect Park on a Saturday morning is pretty much the furthest thing from an EPA superfund site imaginable. It looks so idyllic that if it were in an allergy-medicine commercial, you would say that all the fun and beautiful people strain plausibility. Yet less than two miles downhill—thanks to myriad causes, including this beautiful park—the fetid, poisoned Gowanus Canal, which the EPA calls "one of the nation's most extensively contaminated water bodies," is festering.

That's why Eymund Diegel is up here in Prospect Park, blowing up a 5-foot-wide red balloon. The environmental planner and map maker for the City of New York is preparing to hunt down the creeks that Brooklyn buried but couldn't kill, in hopes that what he finds up here can help revive the canal below. As a very cool dad, Eymund's group, itself birthed from the community-based technology sharing site Public Lab, has a very-dad moniker: CSI. Creek Scene Investigation.

It's still off-leash hours in the park when I arrive, so dogs of every breed and size are casually strolling around us, sniffing and lying down on our stuff as I shake Eymund's hand and set my bike down. Tiny children are kicking tiny soccer balls at tiny goals to our right; to our left, yoga mats are being unrolled. The capoeira class would arrive around 11.

In almost any other context, our helium canisters, maps, and camera holders made out of old milk jugs might look downright suspect, but against the Prospect Park Saturday bliss, we're just another torn-from-Wes-Anderson players in the human panoply.

Image: Public Lab, used with permission

But before it refashioned in the 1870s as Brooklyn's backyard, Prospect Park was marshland. Thanks to the clay endemic to New York's soil, springs from the Long Island aquifer were forced to the park's fairly high relative elevation, which formed a mini-continental divide. "This goes to Jamaica Bay," Eymund says, pointing east across the dry, grass field. He then points west, "and this goes to Gowanus."

Full of PCBs, coal tar wastes, heavy metals, and sewage—a microbiologist told Popular Science that "every kind of imaginable pathogen" could be found in the canal—the Gowanus is a testament to Brooklyn's past as a home for manufactured gas plants, mills, tanneries, and chemical plants. 

For a period after World War I, it was the busiest waterway in America. Now it sits still and stinking, right at the confluence of several of the borough's most expensive neighborhoods, an EPA superfund site that runs past the fanciest imaginable Whole Foods, a premium ice cream shop, and public housing high rises. It is literally a place where dolphins go to die, and it's our fault.

Image: Ethan Hein/Flickr

"The Gowanus Canal is historically a creek-fed tidal estuary," Eymund told me via email later. "When the creeks were buried, we destroyed their ecological and cleaning functions and created the Gowanus Canal's water quality problems. By identifying where those streams were buried alive, and still survive, we can help restore a major neighborhood recreational and fishing amenity, and make the water fun again for canoe groups."

The morning's goal is get pictures of the whole lawn and then to look at the vegetation. Nature can be built over, but it can't be stopped, and the long-buried waterways are still written on the surface in grass. The type of grass growing reveals the soil below, where the patterns of the historic streams persist. Although unseen, they're still adding to the Gowanus watershed through combined sewers, much to the detriment of the water and the health of those who would enjoy it.

"Combined sewers have limited capacities, and when it rains, they overflow poop and condoms into our Canal where we canoe," he says. "By getting clean stream water out of the sewers, and diverting them to parks, and Street Creeks, we can improve the water quality."

So Eymund has been mapping Brooklyn's cryptocreeks upstream from the canal, a David Livingstone venturing into the past. Instead of working for the crown, he's working with the New York City Department of Environmental Protection, helping them find places to implement their Green Infrastructure Plan. He wants to bridge the local expertise, which in this case is property owners whose basements are always flooding, with the EPA's clean-up efforts in Gowanus. As the canal is paying for the whole borough, the clean-up has to involve the whole borough, creating a more sustainable, greener Brooklyn.

The map so far. Prospect Park is in the bottom right corner. Image: Eymund Diegel, used with permission

The canal's problems are a product of how the whole watershed is treated, and so to work with the environment rather than fighting against it, the whole watershed should be considered in the clean-up. Plus, instead of having a bunch of condom-laden water showing up in someone's basement, rainwater could form a frog pond in a park. The CSI's vision of Brooklyn is greener and cheaper. Win-win.

The on-going results are being mapped and posted online, as well as being presented to the powers that be.

As an example, Eymund told me about approaching the Department of Environmental Protection, and asking them to change their engineering design for a storm sewer running under Brooklyn's Third Avenue. Instead of building a whole new outflow for 50,000 gallons per day of storm water, CSI suggested diverting it one block further south to the First Street Basin, where the stream bed was historically. 

"By directing the water there, we can use it to rebuild filtering wetlands in the side basins as part of the Superfund Cleanup Plan, and improve our water quality," he said. Win-win.

Of course, the idea of working with nature, rather than just running over it is contrary to how things were done for a long time, and so just finding the streams takes some work, albeit, work that involves being in the park on a beautiful summer morning.

That day's plan is to send the balloon aloft carrying two regular point-and-shoot digital cameras, like everyone had before smartphones, that are hacked to take pictures every 10 seconds. Though the whole endeavor is designed to be both cheap and sustainable—the eight- and 12-megapixel cameras were ten-buck rescues from the e-waste warehouse on Nevin Street, by the canal—Eymund excitedly tells us we'll be using a new balloon to look for where the creeks were buried.

Image: The author

Sixty cubic feet of gas is fed into the balloon, as Eymund's daughter keeps it off the ground. He keeps telling her, "Don't let it go! Can you—can you not let it go?!" while she rolls her eyes and says, "I'm just going to let it go; is that okay?"

All of a sudden, it seems, the balloon goes from held up to held down. Three kite lines run from it, as it struggles to rise, burdened with the cameras. Once its up high enough, Eymund directs the balloon through the park.

Image: The balloon, used with permission

As the group moves through the park, people keep asking, "what are you doing?" which is both fair and earnest sounding, as is their "oh cool!" after we explain. I'm told the reaction to the photographing balloon by the park's sunbathing denizens can, understandably, be more suspicious, but it's sort of cloudy when we're out.

But there's the secret other, savvy part of balloon mapping: it gets people interested, and is interested in people. Ever the city planner, the pictures are useful for "post-occupancy analysis, to understand how people actually use urban spaces and parks." 

"Last weekend's Prospect Park pictures show that Homo Sapiens var. parkslopensis prioritizes colonization of the tree / grass edge, and only later moves into the open areas where the Wild Things are," Eymund says.

Naturally enough, kids love the balloon. Naturally enough, this love is encouraged.

As we walk he spies a family making huge soap bubbles that are chased by children and dogs alike. "Let's get the bubbles!" Eymund shouts across the lawn.

The overcast day dulls the contrast, and makes it difficult for the cameras to focus, so the human element emerges as the most successful, but Eymund is interested in the long game. 

"Restoring our urban natural systems will be a long term process that could take 30 to 50 years," he tells me, adding perhaps optimistically, "The City of Zurich (Switzerland) restored all their urban streams over a decade."