The New York Harbor Storm-Surge Barrier is a proposed flood barrier system to protect the New York-New Jersey Harbor Estuary from storm surges. The proposed system would consist of one barrier located across the mouth of Lower New York Bay, possibly between Sandy Hook (N.J.) and Rockaway (N.Y.), and a second on the upper East River to provide a ring of protection to most of the bi-state region. Through extensive use of floodgates, both barriers would have largely open cross-sections during normal conditions to minimize environmental impacts on the estuary and port operations. Alternatively, the southern barrier could be located between Coney Island and Staten Island. A storm surge barrier at this location would be half as long, but it would require supplemental barriers across the entrances to Jamaica Bay and the Arthur Kill. To address the problem of sea level rise, smaller-scale projects to increase seawall heights or otherwise raise vulnerable coastlines would be necessary. Thus a storm-surge barrier system combined with coastline adjustments would form a two-tiered strategy to protect the region. The barrier system could also be extended eastward, filling in the gaps between barrier islands, to protect the various communities lining the south shore of Long Island.
The proposal was developed in the wake of Hurricane Sandy by the Metropolitan NY-NJ-LI Storm Surge Working Group (SSWG), composed of prominent civic leaders, social scientists, oceanographers, engineers, and architects. The group is chaired by Malcolm Bowman, a professor of physical oceanography at the State University of New York at Stony Brook. Within the proposed barrier system lies crucial infrastructure such as the seaports and maritime facilities; ground-level and underground transportation terminals; three major international airports; subway and roadway tunnels; hospitals; communication centers; the industrial complex of northern New Jersey; as well as the millions of residents at risk in New York City and coastal New Jersey north of Sandy Hook.
Need
The New York-New Jersey Harbor is vulnerable to storm surges that threaten to inundate the region, put in danger large numbers of the metropolitan area's residents, devastate much critical infrastructure and damage some of its most important economic assets. At particular risk are the most vulnerable, low-income communities located in many public housing projects located on low-lying land near to the coast. The source of energy for all hurricanes is the elevated temperatures of the tropical Atlantic Ocean and the associated warm surface temperatures of the Gulf Stream flowing northwards along the eastern seaboard. Accordingly, hurricanes are most dangerous when their track lies slightly offshore. Hurricane Sandy's power came from unusually warm water lying off the mid-Atlantic Coast and the merging of two major storm systems. Technically, Sandy was downgraded from a category one hurricane to an extra-tropical storm just before it made landfall in New Jersey on October 29, 2012. Nevertheless, as the largest storm in extent ever recorded by the National Weather Service (at 1100 miles in diameter), Sandy had severe storm-surge impacts on New York and New Jersey. Because of global warming, oceanographic and meteorological experts currently predict that increasingly warmer future ocean surface temperature is the "new normal", implying that extreme weather events like Hurricanes Sandy and Maria could become more intense and possibly more frequent during future hurricane seasons. As the world's oceans steadily become warmer, storms are becoming stronger and larger. These storms will cause more damage if they follow past storm tracks. For example, research suggests that hurricanes that have hit the New York City area since 1970 are more intense or have larger wind fields, producing higher storm surge and flood risk. When added to rising sea level, what was a 500-year flood event before the anthropogenic era (i.e. pre-1800) is now a 24-year flood event and in 30 years will be a 5-year flood event. The risks to the New York Metropolitan Region also include wind and flooding damage from winter nor’easter storms which can be as serious, or even more dangerous, than rarer hurricanes. While hurricanes are short and violent, nor’easters tend to persist longer — for several days — also producing large storm surges that ride atop successive high tides that occur twice daily. Adding to storm surge risks, sea levels are also rising. Over the last 160 years the National Oceanic and Atmospheric Administration's (NOAA's) Battery Park tide gauge has measured the rate of sea-level rise as one foot per century. But sea level rise has begun to accelerate, potentially adding an additional 3–6 feet to current sea level by the end of this century, or possibly more if the melting of the Greenland ice sheet continues at ever increasing rates and huge chunks of ice around Antarctica continue to break off.
Precedents
Similar, albeit more modestly-sized, but still highly effective storm-surge barriers have been in operation for nearly half a century in three New England communities — the Stamford Hurricane Protection Barrier in Stamford, Conn.; the Fox Point Hurricane Barrier in Providence, R.I.; and the New Bedford Harbor Hurricane Barrier in New Bedford, Mass. Hours before Hurricane Sandy struck Stamford, the city's 17-foot-high movable barrier was closed to withstand an over-11-foot storm tide which struck western Long Island Sound (at some locations on the sound, the storm tide was even higher than the 11.5-foot storm tide measured at The Battery in New York City), devastating every waterfront community on the northwestern coast of the sound — except Stamford. Larger barrier systems protect more than a dozen major cities, including the Delta Works protecting the south of the Netherlands and the MOSE Project protecting Venice. New storm-surge barriers on Lake Borgne and Lake Pontchartrain are part of the protection for New Orleans after Hurricane Katrina. The famous Thames Barrier is typically deployed an average of about twice per year, protecting the heart of London from excessive tidal flooding. The Greater London Authority is currently studying proposals to strengthen its defenses.
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