Subterranean cartographers are bringing to light the dark, tangled truths buried under the streets.
Before a single raindrop fell, Alan Leidner knew the waters could rise and throw the city into darkness. On this point, the maps were as clear as a crystal ball. All you had to do was look.
It was 2010, and Leidner was consulting for the government services company , contracted by the U.S. Department of Homeland Security to identify potential threats and vulnerabilities in the nation's critical infrastructure. Leidner was examining a region that included New York and New Jersey. One day he was thinking about the area's electrical power grid. He consulted some flood projection maps the Federal Emergency Management Agency had prepared. Then he stared at a map of the grid maintained by , the region's power supplier. And it just jumped out at him: The substation at East 13th Street, on the banks of the East River, was smack in the middle of a flood zone.
Leidner voiced his concerns with utilities, hospitals, and other major facilities. "The reaction was mostly, 'Eh,'" he recalls, as we sit in the Tribeca offices of the , where he directs the nonprofit organization's Center for Geospatial Innovation.
When Hurricane Sandy arrived in 2012, barreling up the Eastern Seaboard and heading straight for New York, the projected a massive surge in New York Harbor. "I realized it would hit the flood maps that FEMA produced," Leidner says, "which meant East 13th Street was about to be flooded." He churned out memos, with maps attached, urging the response community to prepare. Con Ed (as the utility is known) workers hastily constructed barriers around the transformers that connected to buried wire ferrying current for blocks. But when the water breached the river wall and spilled across FDR Drive toward the substation, the barriers weren't enough.
Leidner called up some images on his laptop: a white-hot nova as the transformers exploded; and in the aftermath, an overhead shot of Manhattan, dark below 34th Street (save for a sliver of light in Battery Park City), a blackout that lasted three days. The damage included the shutdown of NYU Langone Medical Center and Bellevue Hospital—their backup generators failing, Leidner notes, because critical components were located in basements, subject to the same East River flooding that swamped the substation.
"We were churning out maps like crazy—something like 3,000 in six weeks. It was a real watershed moment for GIS"
Leidner believes, fervently, in the power of geospatial data, "interfacing multiple map layers from different sources to come up with valuable intelligence," as he explains it. In the '90s, he led the creation of a map of New York City that stands as a pre-Google Earth model of urban cartographic complexity, troves of data integrated to reveal the location of everything from billboards to curbs. What it doesn't encompass is the subterranean city, the sprawling network of infrastructure and the natural features that surround it. Leidner is convinced that if such a map had been available before Sandy, as a resource shared and referenced by the multiple players who keep the city running, the precariousness of East 13th Street would've been obvious. But, he hopes, by the next major hurricane, planning ahead will be easier. Under his direction, New York is on the verge of completing the world's most complex underground map—and therefore the most detailed realistic picture of the interlocking systems that make a city work. That, Leidner says, will improve public safety, help officials better manage rapid growth, and usher in the era of "smart" cities, in which sensors and other automated technologies manage the flow of daily urban life.
Because of data from satellites, we can now map the world down to about 6 inches. We've almost reached the point Jorge Luis Borges describes in his short story "On Exactitude in Science," in which cartographers built "a Map of the Empire whose size was that of the Empire, and which coincided point for point with it." But the world beneath our feet remains shrouded in darkness. "Light and radio waves don't go through dirt like they do air," says George Percivall, chief technical officer for the , which is helping to develop global standards for underground mapping. "The next frontier, in both a literal and figurative sense, is underground."
