With its dense population and distinctive coastline, New York is especially vulnerable, with Manhattan at the center.
The famous island can be pounded by storm surges from three sides: from the west via the Arthur Kill, from the south through the Upper Bay, and from the Long Island Sound through the East River. Relatively shallow depth offshore allows storm waters to pile up; the north-south shoreline of New Jersey and the east-west orientation of Long Island further channel gushing seas right at Manhattan.
Some believe that Sandy was bad enough at least to advance more serious study of stronger protections. "I think the superstorm we had really put the fear of God into people, because no one really believed it would happen," said urban planner Juliana Maantay at Lehman College-City University of New York.
But nearly all flood researchers interviewed by the AP voiced considerable skepticism about action in the foreseeable future. "In a half year's time, there will be other problems again, I can tell you," said Dutch urban planner Jeroen Aerts, who has studied storm protections around the world.
William Solecki, a Manhattan-based Hunter College planner who has been at the center of city and state task forces on climate change, guessed that little more will be done to prevent future flooding beyond "nibbling at the edges" of the threat.
In recent years, the city has been enforcing codes that require flood-zone builders to keep electrical and other critical systems above predicted high water from what was until recently thought to be a once-in-a-century storm. Sealing other key equipment against water has been encouraged. The city has tried to keep storm grates free of debris and has elevated subway entrances. The buzz word has been making things more "resilient."
But this approach does little to stop swollen waters of a gigantic storm from pouring over lower Manhattan. "Resiliency means if you get knocked down, this is how you get back up again," huffs activist Trentlyon. "They just were talking about what you do afterward." He said Sandy's flood water rose to 5 feet at street level in Chelsea, where he lives on the western side of lower Manhattan.
The city has at least toyed with the idea of barriers and even considered various locations in a 2008 study. "I have always considered that flood gates are something we should consider, but are not necessarily the immediate answer to rush toward," said Rohit Aggarwala, a Stanford University teacher who is former director of the New York mayor's Office of Long-Term Planning and Sustainability.
Unswayed by Sandy, Mayor Michael Bloomberg and his assistants have been blunter. Bloomberg said barriers might not be worthwhile "even if you spent a fortune."
Deputy Mayor Cas Holloway said no specific measures — whether more wetlands, higher seawalls or harbor barriers — have been ruled out because "there's no one-size-fits-all solution." But he compared sea barriers to the Maginot Line, the fortified line of defenses that Germany quickly sidestepped to conquer France at the beginning of World War II.
"The city is not going to be totally stormproof, but I think it can be very adaptable," he added. He said that new flood maps informed by Sandy are being drawn up, and he suspects they will extend the zones where new developments must install critical equipment above flood level.
Computer simulations indicate that hard barriers, which have worked elsewhere around the world, would do a good job of shielding New York neighborhoods behind them. But they'd actually make flooding worse just outside the barriers, where surging waters would pile up with nowhere to go.
The patriarch of this research is Malcolm Bowman, a native New Zealander who leads a passionate cadre of barrier researchers at Stony Brook University on the northern shore of Long Island. His warnings have mostly gone unheeded. "I feel like a biblical prophet crying in the wilderness: 'The end is near!'" Bowman said.