New York Harbor Storm-Surge Barrier

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The New York Harbor Storm-Surge Barrier is a proposed flood barrier system to protect New York-New Jersey harbor estuary shores from storm surges. The proposed system would consist of one barrier located across the mouth of Lower New York Bay between Sandy Hook (N.J.) and Far Rockaway (N.Y.) and second on the upper East River to provide a ring of protection to most of the bi-state region.

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, or bifurcated, 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 New York/New Jersey Metropolitan Storm Surge Working Group, composed of prominent entrepreneurs, civic leaders, social scientists, oceanographers, marine ecologists, meteorologists, engineers, architects, economists, attorneys and media experts. The group is chaired by Malcolm Bowman, a professor of physical oceanography at the State University of New York at Stony Brook. Within the 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.

Video New York Harbor Storm-Surge Barrier

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 gained its formidable power by unusually warmer water lying off the mid-Atlantic Coast and the merging of two major storm systems. Sandy was technically downgraded by the National Weather Service from a category one hurricane to an extra-tropical storm, just before it made landfall in New Jersey on October 29, 2012. However, it was the still the largest storm in extent ever recorded by the National Weather Service, with an enormous diameter extending over 1,100 miles.

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 will become more intense and possibly more frequent during future hurricane seasons. The reality is that the world's oceans are steadily becoming warmer; storms are getting stronger, larger, and correspondingly will cause more damage. 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 sea level, to the extent that what was a 500-year flood event before the anthropogenic era (i.e pre-1800) is now a 24-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 is expected to accelerate, 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.

Maps New York Harbor Storm-Surge Barrier

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 a greater-than-eleven-foot storm surge which struck western Long Island Sound (even higher than the 9.5-foot harbor surge 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 Thames Barrier protecting London; the Delta Works protecting the south of the Netherlands; the MOSE Project protecting Venice; and the Saint Petersburg Dam protecting St. Petersburg, Russia. New storm-surge barriers on Lake Borgne and Lake Pontchartrain are part of the protection for New Orleans after Hurricane Katrina. London's famous regional surge barrier is typically deployed up to 12 times per year, protecting the heart of the bustling city from flood devastation. The Greater London Authority is currently studying proposals to strengthen the Thames Barrier to withstand future severe storms and rising sea level, as well as planning ambitious, even larger systems further down the River Thames.

The barrier most similar to the proposed New York barrier is the one in St. Petersburg. Historically, the storm surges from the Gulf of Finland had caused over 300 floods in the city, several of which had a massively devastating effect. The barrier's first use to hold back Baltic Sea from flooding into Neva Bay took place November 28, 2011, just months after it was completed, and limited sea water rise to below flood level. The new storm-surge barrier prevented the 309th flood in the history of the city and saved some 1.3 billion roubles of possible damages.

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Background

Well before Superstorm Sandy struck Metropolitan New York in October 2012, experts were warning that a major storm could cause significant flooding and damage. With funding from the Rockefeller Foundation, Mayor Michael Bloomberg, convened the New York City Panel on Climate Change in August 2008 to investigate the city's vulnerability to a variety of climate-induced risks including the risk of a major storm-surge event. At about the same time, the American Society of Civil Engineers organized a three-day conference and subsequently published a report entitled "Storm-Surge Barriers to Protect New York City Against the Deluge."

After Hurricane Sandy devastated the New York - New Jersey metropolitan area in 2012, governments struggled both to recover and to plan better protection for the future, including regional storm-surge barriers. In his January, 2013, State of the State address, New York Governor Andrew Cuomo proposed to "work with other government partners to timely complete a comprehensive engineering evaluation of these potential barrier systems."

The City of New York, under Mayor Michael Bloomberg, organized a "Special Initiative for Rebuilding and Resiliency" (SIRR), which developed a blueprint for reconstruction that was released in June 2013, only eight months after the storm. That over-400-page document describes the demographics and morphology of the region, the storm and its impacts; provides background on extreme weather events including non-storm events such as heat and intense rainfall; describes various resiliency measures and strategies; and describes specific initiatives, studies and projects to be undertaken. Some of these projects are underway, using a combination of federal and local funds.

City and regional response

Despite Governor Cuomo's announced interest in storm surge barriers, Mayor Bloomberg was reluctant to proceed. But the City asked Dr. Jeroen Aerts, a professor of water and climate risk with the VU University of Amsterdam, the Netherlands, and an expert on water risk management, to compare the costs and benefits of a regional barrier system with those of smaller-scale changes like building levees around sewage treatment plants, raising subway stations entrances, constructing local storm-surge barriers, and flood-proofing or raising buildings according to the FEMA-run National Flood Insurance Program standards. At the same time FEMA intends to redraw flood maps for New York City, placing a much larger area in the flood zone.

Dr. Aerts' report indicated that, assuming a middle scenario for climate change, which includes the combined effect of sea-level rise and increased storm activity, the benefit/cost ratio of investment in a regional barrier would be similar to the ratio for investment in smaller-scale changes. Despite that result, the City's SIRR report dismissed the regional barrier idea without any further study. The report listed seven reasons for doubt about the feasibility:

1. Such a system of barriers would be extraordinarily expensive -- perhaps costing $20-25 billion to build.
2. Harbor-wide barriers would require a design, approval and construction process that could take two to three decades to complete.
3. The possible hydrodynamic and environmental impacts on fish migration, siltation, river flow, and water quality are likely to be substantial and are not yet known.
4. To make the project work, massive levees along adjacent coastal areas, including on the Rockaway Peninsula and possibly Coney Island and Staten Island would have dramatic impacts on the character of the beaches and adjacent neighborhoods that may prove to be highly disruptive.
5. Any barriers would create an "insiders/outsiders" dynamic, with only those behind the barriers receiving maximum protection, leaving densely developed communities along the South and North Shores of Long Island and the Jersey Shore outside the protected zone.
6. A harborwide barrier project may also cause additional flooding in areas outside the barriers, making those communities more vulnerable than they would be without such barriers.
7. Finally, since the barriers would be open most of the time (to allow navigation), it would represent a major public investment that would end up doing nothing to address the growing problem of rising sea level.

Instead of a barrier system, the SIRR report identified a plethora of local measures that could be taken by the City. The goal of these measures is to protect vulnerable areas of the city with projects that would be relatively inexpensive, effective and quickly designed and constructed. They include local walls or barriers against storm surge on some sections of the coast. For example, a barrier has been funded as part of an inner defensive ring for Lower Manhattan.

At the same time that the city was implementing its own local flood mitigation strategy, the MTA, Port Authority of New York and New Jersey and many major institutions and private companies adopted their own localized plans for their facilities. Hoboken and other cities in the region have initiated their own local measures, with support from the U.S. Department of Housing and Urban Development's Rebuild by Design competition. The U.S. Army Corps of Engineers has conducted coastal storm risk reduction studies and beach restoration and resiliency projects.

Because of the variety of governmental entities involved, as well as differing community reaction, there is a lack of coordination on goals and standards of storm protection among the various projects. As a result, these scattered efforts have proved to be more difficult to execute, as well as more expensive than expected, and raise doubt about how much of the shoreline will be protected in the end.

Counterarguments

Lost in all this activity is the conclusion of Dr. Aerts' study -- that because of the expectation of rising sea level and increased global warming, by 2040 the benefit/cost ratio of a regional barrier system will far exceed the ratio for the measures the City is now taking, that a regional barrier may be needed soon, and that planning for it should begin now. "As a Dutchman," Dr. Aerts said, "you are quite surprised to see a large city like New York -- so many people exposed -- and no levees, no protection at all. [That] was astonishing to me. Don't rule out yet the barriers ... you need a barrier."

The Storm-Surge Working Group has provided answers to all the objections raised by the City.

1. The barrier system alone would cost less, perhaps $12-18 billion. Some of the additional cost to shore up areas on the sides of the barriers are scheduled to be spent anyway, for example in dune-building projects on the Rockaway peninsula.
2. If a barrier takes a long time to implement, so do local projects. It is now over four years since Sandy struck and the local projects have yet to begin final design, and are experiencing the same flaws (costs, public resistance, etc.) that were leveled at the regional storm surge barrier approach.
3. With regard to environmental impacts, the barrier gates would be closed only for a few hours before, during and immediately after a major storm surge. Over 99.9% of the time, barrier structures would remain open so as to minimally hinder tides, harbor flushing, river discharge, fish migration and healthy marine ecosystem functioning. An environmental impact study would evaluate whether any hindrance posed by the structure is outweighed by its benefit.
4. Levees will indeed have to be built in the Rockaways and Sandy Hook, but not around Coney Island, Staten Island and northern New Jersey, since they are all within the perimeter of protection of the Outer Harbor Gateway. Levee design will face many of the same complex problems that the SIRR projects are dealing with: protecting dense urban communities but minimizing disruption of existing water views and access.
5. Because of the immense lengths of the New York Bight and Atlantic shorelines (Montauk Point, N.Y. to Cape May, N.J.), research has shown that ocean water displaced by the barrier system would only increase coastal surges adjacent to the barrier by two inches on the ocean side, and a few inches more along western Long Island Sound communities. There would be no "side splash" reaction, which is commonly misunderstood.
6. While ocean shore communities outside the region would not be protected by the two barriers protecting New York Harbor, it would be possible to expand the area to be protected by extending barriers eastward along the south shore of Long Island, and south along the Jersey shore.
7. The SIRR report, itself, found that by the 2050s 43 miles, or about 8%, of the city's coastline could be at risk of inundation during non-storm conditions. These coastal areas will need to be raised or otherwise protected regardless of additional protections against storm surge.

The bifurcation approach of protecting local coastal areas against slowly changing sea level rise, together with 25-foot offshore storm barriers to hold back surges of future storms, will give future civic leaders 100 to 150 years to protect, and if necessary migrate, our urban metropolitan civilization to higher ground, and to adopt even more sweeping measures to protect the region from both sea level rise and storm surges.

In answer to another objection -- that restored natural systems, such as created wetlands and oyster beds could provide the same protection -- the reality is that while these proposed solutions can reduce wave action slightly, reinforce presently fragile wetlands and in some cases improve water quality (and should be included in local responses), they would be simply overwhelmed by storm surges of the magnitude of those experienced during Sandy. This is not to say that nourishing ocean beach berms is not an important ongoing activity. In fact most of the coastline of the Netherlands is protected in this way.

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See also

• Geography of New York-New Jersey Harbor Estuary
• Vision 2020: New York City Comprehensive Waterfront Plan
• Sea Bright-Monmouth Beach Seawall
• New York Bight
• Effects of Hurricane Sandy in New Jersey
• Effects of Hurricane Sandy in New York
• 1893 New York hurricane
• 1938 New England hurricane

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References

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External links

• Slide presentations, videos, and conference summary from the May 18, 2017 conference convened by the Storm-Surge Working Group and the National Institute for Coastal and Harbor Infrastructure.
• US Army Corps of Engineers' New York/New Jersey Harbor & Tributaries Focus Area Feasibility Study.
• HUD's Rebuild by Design Program
• NOAA's Consortium for Climate Risk in the Urban Northeast website and YouTube channel.
• Tracy Metz talk, "Sweet and Salt: Water and the Dutch," Oct 3, 2012.
• Lower Manhattan Coastal Resiliency
• National Geographic channel on North Sea Barrier
• Regional Plan Association, "Under Water: How Sea Level Rise Threatens the Tri-State Region," December, 2016.
• Aaron Naparstek, "Storm Tracker: A history of hurricanes in New York -- including the day in 1893 that Hog Island disappeared for good," New York Magazine, Jan. 29, 2008.

Source of article : Wikipedia