The City and the Sea

East River Bikeway under the Brooklyn Bridge, Lower Manhattan. [Photo by junehug]

On the southeast shore of Manhattan, a narrow stretch of sand juts out from the East River in the shadow of the Brooklyn Bridge. Traffic thunders overhead on the FDR Drive. A scattering of jagged wood pilings, slick with oil and vegetation, spans the distance to the hulking bridge anchorage. According to my guide, Carter Craft, this is one of the few places on the island’s 32-mile shoreline where you can “get down and touch the water.” After you jump the fence, of course.

Craft pointed to an old pipe running along the pilings. “That’s actually one of the few wooden pipes you still see out in the harbor,” he said. “It probably goes back to the 1830s.” Craft is director of Long Range Planning and Development at the Urban Assembly New York Harbor School. He brought me here, to this spot under the bridge, only a few weeks after the storm surge of the post-tropical cyclone Sandy crested over that beach, over the bulkhead, across a bike path and small park, and into Lower Manhattan streets — Water, Pearl — whose names recall an absent sea.

It’s an ideal vantage from which to understand the city’s modern relationship to its historic waterfront. For almost two centuries, fishing boats offloaded their catch at the Fulton Fish Market in Lower Manhattan. According to Craft, the wood pilings may date back to the cement or asphalt plants that were once common under the city’s bridges; a severed steel pipe recalls the pre-Clean Water Act industrial era. In the late 20th century, as manufacturing and maritime activity declined, the old working harbor was in serious decline. (In 2005 the Fulton Market itself relocated to a new site in the Bronx.) But today New Yorkers are rediscovering the waterfront — this time as a place for recreation. As we talked Craft and I were standing midway along the East River Esplanade, a public space designed by SHoP Architects that will stretch two miles along the shore when finished later this year.

And as Hurricane Sandy showed, the sea will not be forgotten. At a parking lot under the FDR Drive, where a few months earlier I had queued for locally sourced tacos at the New Amsterdam Market, Craft told me the water would have been over our heads. We walked up Old Fulton Street, as workers hoisted sheetrock against the façade of a Pizzeria Uno and a pair of tourists stopped to kiss. A branch of the clothing chain Superdry — the irony was poignant — was still closed, its windows marked with a yellow sticker: “Restricted Use.” Around the corner, on Water Street, Craft showed me a high-water line marked by white splotches on a russet brick wall, “Salt?” I asked. “That could be phosphorescence,” he said. “Mineral residue in the brick, trying to get out.” It seemed a kind of secret graffiti.

Storm surge damage near the South Street Seaport. [Photos by Mira John]

Walking in lower Manhattan, you feel a curious tug at the legs: Elevation. New Yorkers tend to assume that Manhattan Island is flat, but here by the waterfront the streets have a decided slant. Like the name Mannahatta itself (after the shell middens of the Lenape, says the landscape ecologist Eric Sanderson), the terrain reflects an obscured past, the succession of infill building below Pearl Street. In the 19th century, the owners of so-called “water lots” — provisional land that surfaced between tides — would deposit garbage and other materials on the shore; as landfill accrued (and subsided) between the piers, the pier-head line would become the next new waterfront street. It was these landfill blocks — along with former wetlands converted to development, like LaGuardia Airport — that would fare worst during the storm; as if the city were being sent a telegram from the past: Geography is destiny.

“The Ocean Is Not Filled with Perrier Water”

All those old vanished piers are depicted in a 19th-century Census Office lithograph, “The Original Topography of Manhattan Island,” which itself has been replicated in a tile mosaic at the South Ferry Station of the subway. The image prefigures the contours of today’s so-called “slosh maps” — a rather mordant acronym for Sea, Lake, and Overland Surges from Hurricanes — that indicate which land areas will be flooded, based on probabilistic modeling from the National Weather Service.

As I toured the station with Joe Leader, the Metropolitan Transit Authority chief of maintenance, I found more traces of the storm surge: here on the stairs, rust-colored water lines; below, on the platform, a dancing swath of mud and matted debris near the vaulted ceiling. At the station’s northern entrance, Leader showed me yet another line. On the night of the storm, he was heading into the subway with an escort of National Guard troops when they encountered a sight he still shudders to recall: Water coming upthe stairs.

On a clear, dry day, the MTA pumps out some 16 million gallons of water — from groundwater seepage, burst water mains, rogue leaks — across the extensive subway system. In the aftermath of Sandy, some 27 million gallons were pumped out of the Montague Street Tunnel alone. “I had never seen anything like that,” Leader said. “The hard thing to understand was, ‘Where’s the water coming from?’ The surge was over.” But water had collected at the end of the tunnel, in the plaza shared by the South Ferry Station and the Staten Island Ferry Terminal; the tunnel filled up like a bathtub.

Top: South Ferry subway platform. [Photo by Patrick Cashin/MTA] Bottom: South Ferry station entrance with map, “The Original Topography of Manhattan Island.” [Photo by Benjamin Kabak]

There should be a science of water lines, an archaeology of standing water. What history can we read in those stratigraphic bands? Was the water moving, or was it still? Where did it come from, what did it bring? Today the lines are the only real evidence (surveillance cameras went out with the power) of what happened that night at the South Ferry Station, Leader said, when a bundle of construction timber, driven by surge waters, smashed through a plywood barrier at the station entrance, then through the turnstiles and down the stairs, like a passenger, striking the aluminum railing with such force that it destroyed the wall and left the railing horribly twisted on the floor.

In hurricanes, it is wind we fear. We picture palm trees bending behind a weather reporter at the beach. But water is the real enemy. One cubic foot of water weighs 64 pounds: now imagine enough water to fill a city bus, and you have the equivalent of a 50-ton battering ram with colossal power. To learn more I met with Nicholas Coch, a geologist and hurricane expert at Queens College who takes a somewhat saturnine view of New York’s weather readiness; in his office, surrounded by reams of hydrological data, he observed, “I have engineers telling me these windows are rated to 120 miles per hour [wind speed]. I said, ‘Oh, that’s nice, would you like to see me take them out at 30?’ Give me a two-by-four.” In other words, water is powerful, but it’s the stuff caught up in the water that delivers the killing blow. “The ocean is not filled with Perrier water,” Coch said, “it’s filled with debris.” After the initial surge, it’s the ebb surge that inflicts a second round of damage.

Force equals mass times acceleration; for hurricanes, that’s oceanic mass times wave velocity, which can be extreme. During Sandy, the geographic feature known as the New York Bight — which makes the New York metropolitan region especially vulnerable to storm surges — acted as a kind of funnel that accelerated the storm speed as it traveled up the coast of New Jersey and approached New York. And, as Philip Orton, an oceanographer at the Stevens Institute of Technology, explained, the differences in sea surface elevation and pressure between the incoming stormwater and the calm harbor meant that Sandy was “flowing downhill … and moving fast.” Geologist William Fritz, president of the College of Staten Island, reached for a simple household metaphor to describe what happened when the stormwater reached the harbor: “In a bathtub, if you get the right harmonic with your hand going up and down, you can create major sloshes, just because you’re focusing that energy.”

It was that kind of fast-flowing water that picked up the construction timber and sent it barreling through the barricade into South Ferry Station. The failure of a few dollars worth of plywood led to the inundation of the station and its electronic switching equipment, the repair of which is now estimated at about a billion dollars. But as ramshackle as the plywood barrier now seems, it came poignantly close to slowing the water enough so that the station’s pumps, running on an emergency generator, could do their work. At the station’s north entrance, Joe Leader said, a similar barricade held back three feet of water, letting in only a trickle. But the surge from the south possessed such force and volume that it swept through the station; you could mark its furthest advance by a jagged black line near the north stairs. “This storm made me realize how powerful the sea is,” Leader said. “And you start to wonder: Why did people stay in some areas when they should have been evacuated?”

Top: South Ferry subway station. [Photo by Patrick Cashin/MTA] Bottom: Subway entrance barricaded with sandbags and plywood. [Photo by Zoriah Miller]

Narratives of Risk and Recovery

Why did people stay? Why don’t we heed the danger posed by storms and floods? Perhaps it’s due to the cognitive problem of comprehending risk. A 100-year flood sounds vanishingly remote, even if, as an engineer reminded me, it means a 26 percent chance of flooding over the span of a 30-year-mortage. Studies have shown that homeowners are more likely to buy insurance after a flood, and societies are little different. As Jeroen Aerts, a professor of environmental risk management at VU Amsterdam, told me, “I have studied all barrier projects around the world — and all these projects were installed only after a major event.” The Delta Works, the Netherlands’ ambitious flood control regime, was constructed only after the disastrous 1953 flood; it was another few decades before the Thames Barrier, downstream from London, would be operational. As it happened, when Sandy struck, Aerts was in the midst of writing a report for New York’s Office of Long-Term Planning and Sustainability, with recommendations for changes to building codes and planning strictures that would adequately prepare the city for a massive storm.

History overwrites memory, much the way layers of time and sediment erase the traces of ancient storms — dredged up in core samples by “paleotempestologists.” More than a decade ago, Nicholas Coch sent his graduate students in coastal geology to the Rockaways to conduct a routine study. They told him there was garbage on the beach. “I said, ‘Well, this is New York — there’s garbage everywhere.’ They said, ‘No, this is funny garbage.’” What the students had found was various debris, including shards of Wedgewood pottery dating to the 1890s, which Coch then traced to Hog Island, a vacation colony off the coast of Far Rockaway that was almost destroyed by a hurricane in 1893 (today the storm would be labeled Category 2). Hog Island would be rebuilt — a 1902 story in The Brooklyn Eagle describes the owner of the resort as “undaunted” — but eventually it would succumb to the sea; “the final demise of Hog Island is apparently undocumented,” according to the New-York Historical Society, “but it seems to have washed away with the tides sometime in the 1920s.”

As hazy as the view back can be, looking forward presents its own problems. When I caught up with Ed Link, former research director at the Army Corps of Engineers, now at the University of Maryland, he had just returned from an international flood conference in Rotterdam. (It is boom times for flood conferences.) One topic kicking around the conference was the difficulty of defining the very meaning of “risk.” As Link put it, there might be a one percent chance of something happening, “but that’s not risk. Technically, risk includes consequence. It’s not just the probability of something bad happening; it’s how bad that is likely to be.” A FEMA flood map, he points out, is not a risk map: It’s a hazard map.” It might tell you where you’re vulnerable to be flooded,” he continued, “but … it’s not including the consequence side of the equation.” What’s more, numerous factors, such as subsea topography and shoreline geometry, make it hard to accurately model hurricanes and severe storms. When the Army Corps began planning new levees and floodwalls in New Orleans, after Hurricane Katrina, engineers used Department of Defense supercomputers to run 152 historical storm simulations with varying factors, incuding central pressure deficits, intensities, tracks, winds. “Each one of these hurricanes took 12 clock hours to run,” Link said. “We were burning a lot of electrons, but that’s what it took to get a physics-based estimate of the hazard for New Orleans.” And yet, Link continued, “there’s still uncertainty.”

Top: Bathymetry of the New York Bight. [Map by USGS/NOAA] Bottom: Flood hazard areas, New York harbor. [Map by FEMA]

Storm impacts are often worse than predicted due to human changes to the landscape since the last mapping. Raymond Burby, an emeritus professor of city and regional planning at the University of North Carolina, has described two “paradoxes” of government disaster planning. “The safe development paradox,” he writes in a paper published by the Annals of the American Academy of Political and Social Science, “is that in trying to make hazardous areas safer, the federal government in fact substantially increased the potential for catastrophic property damages and economic loss.” This is why disaster declarations — which last year reached their highest mark ever — keep rising. The radio station WNYC has reported on the “rebuilding rush” in flood-stricken areas of New York City, where Small Business Administration loans were granted to more than 10,000 homes and business in flood zones in Sandy’s aftermath.

The “local government paradox,” Burby writes, “is that while their citizens bear the brunt of suffering and financial loss in disasters, local officials pay insufficient attention to policies to limit vulnerability.” He compares Florida and Texas, two states with similar levels of “coastal urbanization and storm history,” and note that they received vastly different claim payments from the National Flood Insurance Program between 1978 and 2002; per-capita payments in Florida, which requires greater comprehensive local planning, were roughly one-fifth those in Texas. Of course, the reason the NFIP exists in the first place is what Burby calls the “adverse selection” problem: “The only people who buy flood insurance are those at high risk of flooding,” he told me. “Insurance works best by spreading risk wisely. It doesn’t work well if only those who are at high risk are buying it.”

All of which raises questions — about the wisdom of rebuilding in places at high risk for flooding — that few politicians, federal or local, seem willing to broach. At a conference at Hunter College a few weeks after Sandy, the outgoing Administrator of the National Oceanic and Atmospheric Administration, Jane Lubchenco, offered an unusually frank assessment. “I think the language, ‘recovery,’ is itself problematic,” she said. “It implies what was — not what could be or should be.” At the same conference William Solecki, director of the CUNY Institute for Sustainable Cities, pointed out that in the past, urban disasters helped to inspire reform; the Great New York Fire of 1835, which caused devastating destruction, prompted calls for a more stable water supply: the result was the Croton Reservoir. Today, of course, the critical challenge is the region’s vulnerability to rising seas and dangerous storms. But what is the way forward? While there is immediate political capital to be gained in the reflexive narrative of recover-and-rebuild, the deeper and more urgent question concerns how New York City will need to be adapted and fortified, and not only in its built environments but also in our mental models.

Levee Syndrome

There was a story going around New York last fall that the Ikea in Red Hook, Brooklyn, had, virtually alone, escaped the storm unscathed because the forward-thinking Swedish corporation, accustomed to adapting its big box to former industrial urban waterfronts, employed preemptive architectural strategies, like raising the store on pillars. Like many things one heard in the weeks after Sandy, this was not true. Chuck Keller, U.S. construction manager for Ikea, offered a simpler explanation: elevating the structure allowed for parking on the ground level. “It’s less expensive that way,” Keller said, “Recently we’ve been raising most of our stores to accommodate parking because we can’t always get 30 acres of land.” It was the economics of urban density, not sage engineering or forward-thinking building codes, that saved the Red Hook Ikea.

Disaster Recovery Center in the restaurant of IKEA, Red Hook, Brooklyn. [Photos by Jocelyn Augustino/FEMA, top, and Shelley Bernstein, bottom]

Whatever the reason, in the weeks after Sandy, the store morphed into an impromptu community center. The café became an ad hoc disaster relief zone, where patrons could rest and recharge their phones. Store manager Frederic Robe told me some conference rooms were even converted into living quarters for displaced employees, using the store’s inventory — temporary versions of the tidy, well-designed bedroom ensembles that throngs of Brooklynites scope out on weekend shopping trips. Which raises a question: in Ikea’s happy accident, is there a vision of the future city — not just New York but all cities in coastal floodplains? Was there a way forward suggested by the elevation of habitable space and critical infrastructure, which allowed the site to absorb flooding with little lasting damage? And in the company’s flexibility (and willingness) to help facilitate emergency response and community rebuilding?

One problem in adapting cities is that while the hydro-dynamic assumptions are shifting rapidly, the built environment is comparatively slow to change. Stephen Cassell, a partner in Architectural Research Office who served on a mayoral task force on “greening” the city’s building code —and who was part of the team that created the 2010 exhibition RIsing Currents at the Museum of Modern Art — pointed out that because buildings last for generations, “we could change the codes today and it’s not going to do much” for the many structures designed to older standards. Which is not to say the city couldn’t have avoided much of the physical damage from Sandy. Conceptually simple precautions like storing hospital emergency generators above the basement level would have made a difference. But heavy infrastructure, like water, seeks its own level, and often that level is underground — where people don’t want to live and where it doesn’t require as much structural support; and often these precautions are deemed cost-prohibitive.

One of the ironies of Sandy is that the subterranean city, typically so practical for the location of infrastructure — from subway tunnels to buried power lines — proved so treacherous. Youssef Hashash is a civil engineer at the University of Illinois who was summoned to New York to join a “Geotechnical Extreme Events Reconnaissance” survey organized by the National Science Foundation. He told me that underground structures fare best in earthquakes, and if there is damage, it tends to be visible: “You see it and you fix it.” In contrast, “flooding goes through everything.” That reminded me of my subway tour with the MTA engineers, who struggled simply to identify all the places where water could permeate the system. And for all the sweeping rhetoric of erecting massive storm surge barriers, there is plenty of lower-hanging fruit. Eugenie Birch, a planning professor at the University of Pennsylvania and former member of New York’s planning commission, noted that the city does not have a single map showing the complex and twisting pathways of all its underground utilities. “In this age of ‘smart cities,’ it ought to become a basic tool for managing the city — knowing where your pipes and wires are,” she said. To this day, when planning new construction, architects and engineers often dust off a Viele Map — also known as the “Sanitary and Topographical Map of the City and Island of New York.” It was drawn in 1865.

Top: Flooded escalator at South Ferry station. [Photo by MTA] Bottom: Damaged pump motor controller circuits serving the L train tubes. [Photo by MTA]

Flood-control mega-projects pose their own complications. Not suprisingly, in these days of public austerity and anti-tax politics, funding for infrastructure is scarce. According to the Organization for Economic Cooperation and Development, the flood control standards for New York City are lower than those of London and Tokyo, and even Shanghai, which has a much smaller GDP. Kate Ascher, author of The Works: Anatomy of a City and a development consultant with Buro Happold, emphasized to me the importance of the national political context, and the many U.S. cities at risk from rising seas and coastal flooding. New infrastructure funding, she noted, will need to be distributed “equitably across the country.” But today the federal government “doesn’t have the money to protect cities in the way that they need to be protected.”

Then there’s the risk of what Jeroen Aerts calls “levee syndrome” — constructing major new infrastructure and then becoming complacent about future danger. “One-third of The Netherlands lies below sea level,” he said. “Yet most people are unaware of that, and assume that the government has and will take care of us. There is danger in that.” In his article on the paradoxes of disaster policy, Burby cites a 1987 FEMA study that estimated that roughly one-third of flood disasters were related to structural failure or overtopping of levees. As Burby told me: “There’s an old saw among engineers that there are levees that have failed and there are levees that will fail.”

Wet and Dry

Franco Montalto, a professor of civil engineer at Drexel University and an expert in urban stormwater management, advocates the “ecosystem services” approach. “Do you build one hard piece of infrastructure to address one potential risk?” he asked. “Or do you invest in distributed, multifunctional infrastructure, like green streets, which can buffer against a variety of climate realities that we’re expecting?” We met in his office in the garment district, along with Bram Gunther, New York City Chief of Forestry, Horticulture and Natural Resources. After Sandy, the two had traveled to Queens to examine a bioretention area — in this case, the triangular landscaped intersection of Nashville Boulevard and 118th Avenue. In a “rough” and early estimate, they calculated that the intersection had absorbed about 153,000 gallons of stormwater from surrounding areas, as well as 1,100 gallons of rainwater, and was able to “filtrate 6 percent of total rainfall and runoff.” As Montalto acknowledges, that’s not a reassuring percentage in the aftermath of an extreme event. But what about a network of hundreds or thousands of green infrastructure systems distributed across the city? In the Flatbush neighborhood near Marine Park, in Brooklyn, for instance, a combination of “healthy marshland” and relatively high ground had, Gunther noted, helped to protect the area. “Is there is some critical mass of wetlands and elevation,” he wondered, “that would keep neighborhoods safe?”

Brooklyn Bridge Park after Hurricane Sandy. [Photo by DumboNYC]

Montalto pointed out that “only a small fraction” of New York City had actually flooded during Sandy. Granted, that fraction was the size of Pittsburgh. But the effects were strikingly localized, and often depended upon peculiar configurations of topography. For instance, as I walked one day through Brooklyn Bridge Park — one of the jewels of the city’s waterfront reengagement — with its director, Regina Myers, she pointed to the playground that is a favorite haunt of my daughter. “Swing Valley was flooded,” Myers said, “but the water didn’t even make it to Slide Mountain.”

So Franco Montalto’s question is important: Do you plan a single, city-wide infrastructure, or develop a network of what he describes as “locally appropriate designs, situated within context”?

Urban designers in New York and indeed worldwide are beginning to discuss to what extent cities should rely on “dry” flood-control measures — hard engineering which works to keep water out — versus “wet measures — soft infrastructures like wetlands, marshes, estuaries — which work to ameliorate or accommodate water, and sometimes to channel it for other uses. New York City is still developing a comprehensive response to superstorm Sandy, which will surely build on the sustainability initiatives of PlaNYC. But in the Lower Manhattan office of Skidmore, Owings & Merrill, you can glimpse major projects that are already adapting to the new realities. SOM partner Roger Duffy and associate director Colin Koop emphasized that the lessons of Sandy are being incorporated into the design process. Referring to a master plan for the Hoboken Terminal of the New Jersey Transit Authority, Koop noted: “The FEMA maps have been updated, and so we’re figuring out where the new first floors will be.” The very phrase — the new first floors — is telling. “In this case the building, on a major commercial street, may need to be six, seven, even eight feet above the sidewalk,” Koop continued. “It’s a significant urban problem: How do you get a master plan approved, and build a great, welcoming, urban street, and deal realistically with the matter of the flood plain?”

SOM is addressing similar issues in the new campus for Cornell NYC Tech — which is interesting not only because it will be one of the largest new master-planned developments (it is scheduled to open in 2017) but also because it is located on the low-lying Roosevelt Island, in the middle of the East River, which partially flooded during Sandy. Duffy and Koop told me that flood-control and sustainability thinking was informing the planning, in part due to the university’s own engineering and facilities staff. Even before Sandy, the client stipulated that the new campus should be able to withstand a 500-year flood.

In response, the designers decided on a 19-foot elevation for the buildings, and then — still before Sandy — 21 feet. (None of this was mandated by city ordinances, except the Con Edison requirement that switching equipment be above 23 feet.) And while the desire for lower-level parking was a factor (echoes of the Red Hook Ikea), so too was the prospect of sea level rise. Cornell’s project manager, Andrew Winters, who formerly headed the city’s Office of Capital Project Development, said the design team was working with the soft infrastructure approach, so that “if there’s a dramatic flooding incident, the campus might flood,” but that won’t be catastrophic. Colin Koop said that much of the landscaping will consist of bioswales and permeable paving. “Realistically, we cannot be in the business of holding the water back,” he said, “We have to be in the business of dealing with the water when it comes onto the site.”