The City Without Us
THE NOTION THAT someday nature could swallow whole something so colossal and concrete as a modern city doesn’t slide easily into our imaginations. The sheer titanic presence of a New York City resists efforts to picture it wasting away. The events of September 2001 showed only what human beings with explosive hardware can do, not crude processes like erosion or rot. The breathtaking, swift collapse of the World Trade Center towers suggested more to us about their attackers than about mortal vulnerabilities that could doom our entire infrastructure. And even that once-inconceivable calamity was confined to just a few buildings. Nevertheless, the time it would take nature to rid itself of what urbanity has wrought may be less than we might suspect.
IN 1939, A World’s Fair was held in New York. For its exhibit, the government of Poland sent a statue of Wladyslaw Jagiello. The founder of the Bialowieza Puszcza had not been immortalized in bronze for preserving a chunk of primeval forest six centuries earlier. By marrying its queen, Jagiello had united Poland and his duchy of Lithuania into a European power. The sculpture portrays him on horseback following his victory at the Battle of Grunwald in 1410. Triumphant, he hoists two swords captured from Poland’s latest vanquished enemy, the Teutonic Knights of the Cross.
In 1939, however, the Poles weren’t faring so well against some descendants of those Teutonic Knights. Before the New York World’s Fair ended, Hitler’s Nazis had taken Poland, and the sculpture couldn’t be returned to its homeland. Six sad years later, the Polish government gave it to New York as a symbol of its courageous, battered survivors. The statue of Jagiello was placed in Central Park, overlooking what today is called Turtle Pond.
When Dr. Eric Sanderson leads a tour through the park, he and his flock usually pass Jagiello without pausing, because they are lost in another century altogether—the 17th. Bespectacled under his wide-brimmed felt hat, a trim beard graying around his chin and a laptop jammed in his backpack, Sanderson is a landscape ecologist with the Wildlife Conservation Society, a global squadron of researchers trying to save an imperiled world from itself. At its Bronx Zoo headquarters, Sanderson directs the Mannahatta Project, an attempt to re-create, virtually, Manhattan Island as it was when Henry Hudson’s crew first saw it in 1609: a pre-urban vision that tempts speculation about how a posthuman future might look.
His team has scoured original Dutch documents, colonial British military maps, topographic surveys, and centuries of assorted archives throughout town. They’ve probed sediments, analyzed fossil pollens, and plugged thousands of bits of biological data into imaging software that generates three-dimensional panoramas of the heavily wooded wilderness on which a metropolis was juxtaposed. With each new entry of a species of grass or tree that is historically confirmed in some part of the city, the images grow more detailed, more startling, more convincing. Their goal is a block-by-city-block guide to this ghost forest, the one Eric Sanderson uncannily seems to see even while dodging Fifth Avenue buses.
When Sanderson wanders through Central Park, he’s able to look beyond the half-million cubic yards of soil hauled in by its designers, Frederick Law Olmstead and Calvert Vaux, to fill in what was mostly a swampy bog surrounded by poison oak and sumac. He can trace the shoreline of the long, narrow lake that lay along what is now 59th Street, north of the Plaza Hotel, with its tidal outlet that meandered through salt marsh to the East River. From the west, he can see a pair of streams entering the lake that drained the slope of Manhattan’s major ridgeline, a deer and mountain lion trail known today as Broadway.
Eric Sanderson sees water flowing everywhere in town, much of it bubbling from underground (“which is how Spring Street got its name”). He’s identified more than 40 brooks and streams that traversed what was once a hilly, rocky island: in the Algonquin tongue of its first human occupants, the Lenni Lenape,
Later, new contours arose, this time routed through rectilinear forms and hard angles, much as the water that once sculpted the island’s land was now forced underground through a lattice of pipes. Eric Sanderson’s Mannahatta Project has plotted how closely the modern sewer system follows the old watercourses, although man-made sewer lines can’t wick away runoff as efficiently as nature. In a city that buried its rivers, he observes, “rain still falls. It has to go somewhere.”
As it happens, that will be the key to breaching Manhattan’s hard shell if nature sets about dismantling it. It would begin very quickly, with the first strike at the city’s most vulnerable spot: its underbelly.
New York City Transit’s Paul Schuber and Peter Briffa, superintendent of Hydraulics and level one maintenance supervisor of Hydraulics Emergency Response, respectively, understand perfectly how this would work. Every day, they must keep 13 million gallons of water from overpowering New York’s subway tunnels.
“That’s just the water that’s already underground,” notes Schuber.
“When it rains, the amount is . . .” Briffa shows his palms, surrendering. “It’s incalculable.”
Maybe not actually incalculable, but it doesn’t rain any less now than before the city was built. Once, Manhattan was 27 square miles of porous ground interlaced with living roots that siphoned the 47.2 inches of average annual rainfall up trees and into meadow grasses, which drank their fill and exhaled the rest back into the atmosphere. Whatever the roots didn’t take settled into the island’s water table. In places, it surfaced in lakes and marshes, with the excess draining off to the ocean via those 40 streams—which now lie trapped beneath concrete and asphalt.
Today, because there’s little soil to absorb rainfall or vegetation to transpire it, and because buildings block sunlight from evaporating it, rain collects in puddles or follows gravity down sewers—or it flows into subway vents, adding to the water already down there. Below 131st Street and Lenox Avenue, for example, a rising underground river is corroding the bottom of the A, B, C, and D subway lines. Constantly, men in reflective vests and denim rough-outs like Schuber’s and Briffa’s are clambering around beneath the city to deal with the fact that under New York, groundwater is always rising.
Whenever it rains hard, sewers clog with storm debris—the number of plastic garbage bags adrift in the world’s cities may truly exceed calculation—and the water, needing to go somewhere, plops down the nearest subway stairs. Add a nor’easter, and the surging Atlantic Ocean bangs against New York’s water table until, in places like Water Street in lower Manhattan or Yankee Stadium in the Bronx, it backs up right into the tunnels, shutting everything down until it subsides. Should the ocean continue to warm and rise even faster than the current inch per decade, at some point it simply won’t subside. Schuber and Briffa have no idea what will happen then.
Add to all that the 1930s-vintage water mains that frequently burst, and the only thing that has kept New York from flooding already is the incessant vigilance of its subway crews and 753 pumps. Think about those pumps: New York’s subway system, an engineering marvel in 1903, was laid underneath an already-existing, burgeoning city. As that city already had sewer lines, the only place for subways to go was below them. “So,” explains Schuber, “we have to pump uphill.” In this, New York is not alone: cities like London, Moscow, and Washington built their subways far deeper, often to double as bomb shelters. Therein lies much potential disaster.
Shading his eyes with his white hard hat, Schuber peers down into a square pit beneath the Van Siclen Avenue station in Brooklyn, where each minute 650 gallons of natural groundwater gush from the bedrock. Gesturing over the roaring cascade, he indicates four submersible cast-iron pumps that take turns laboring against gravity to stay ahead. Such pumps run on electricity. When the power fails, things can get difficult very fast. Following the World Trade Center attack, an emergency pump train bearing a jumbo portable diesel generator pumped out 27 times the volume of Shea Stadium. Had the Hudson River actually burst through the PATH train tunnels that connect New York’s subways to New Jersey, as was greatly feared, the pump train—and possibly much of the city—would simply have been overwhelmed.
