Conference Brief: Protecting New York and New Jersey from Future Disastrous Storm Surges

 Protecting New York and New Jersey from Future Disastrous Storm Surges

Conference Brief 2017-05-18
Metropolitan NY-NJ Storm Surge Working Group
National Institute for Coastal & Harbor Infrastructure [1]

Frontispiece: flooding map resulting from Super Storm Sandy, 29 October 2012 [2]  (courtesy WNYC)

I. Background

 The World Economic Forum has declared that the largest threat to human civilization and the cause of most anxiety is the failure worldwide to mitigate and adapt to the effects of climate change[3]. The fourth anniversary last October of Superstorm Sandy and the associated catastrophic damage, destruction and human misery that resulted is a reminder that the greater New York Metropolitan area (specified here to include northern New Jersey, western Long Island and western Connecticut) continues to be largely exposed to future megastorms.

In fact, the threat grows greater with every passing year due to the expected increase in frequency and severity of extreme storm events, exacerbated by rising sea levels along the eastern seaboard. More than a million residents live at risk from storm surges in communities that are located in the floodplains of the New York City boroughs of Brooklyn, Queens and Staten Island, the south shore of western Long Island and many low-lying communities in New Jersey. Some communities, such as those surrounding Jamaica Bay, have already begun to experience flooding during lunar spring tides, even in settled weather.

Rising sea levels coupled with catastrophic storm surges have prompted many local studies and projects that include hardening coastal infrastructure such as transportation terminals, subway and tunnel entrances; redesigning and lifting the lower floors of buildings; building new and raising existing bulkheads; elevating waste water treatment plants and sewer outfalls; protecting airports; modifying building codes and updating zoning regulations.

But, to date, there have been no comprehensive studies of regional metropolitan flood protection systems, similar to those already in operation (and found to be cost effective) in many coastal cities of global significance in Europe and Southeast Asia. In the absence of a regional approach, New York City and other municipalities in the tri-state area have taken their own prudent steps to advance local flood protection measures which, due to the nature of post-disaster funding, are not part of a coordinated regional protection system.

Notwithstanding this background work and the many world-wide precedents, the City was not enthusiastic about considering a regional system incorporating storm surge barriers.  Just two days after Sandy struck with devastating force, Mayor Michael Bloomberg said of regional protection, “It doesn’t work”. He also stated:

“It would be nice if we could stop the tides from coming in, but King Canute (ancient Danish King of England) couldn’t do it [4], and neither can we.” [NY Times, December 6, 2012] [5]

In the comprehensive SIRR document published in June of 2013 [6], the storm surge barrier concept was described and dismissed in a single page (p. 49).

However, in his January 2013 State of the State Address [7], NY State Governor Andrew Cuomo stated (pp. 231-2):

“Proposals have also been made to build massive multi-billion dollar barriers that are designed to hold back storm surges. One proposal suggests a movable barrier stretching from New Jersey to the Rockaways and another one at the entrance to the East River from Long Island Sound.

Undoubtedly, these barriers can be designed to provide enhanced protection to areas behind the barriers, but they can leave areas outside the barriers’ protective wall even more vulnerable to flooding diverted by the barriers. They also may have substantial ecological impacts that must be evaluated. And it would be many years before these barriers could be in place. But we should not wait to begin the necessary evaluation.

Therefore, we will work with other government partners to timely complete a comprehensive engineering evaluation of these potential barrier systems”.

In the aftermath of Superstorm Sandy, the Metro NY-NJ Storm Surge Working Group (SSWG) was formed to assess the continuing threat of major damage and disruption from future storms and to study how a regional protection approach could best be evaluated and promoted. The group includes business, academic and civic leaders from across the metropolitan area.

II. Regional Protection Systems are Needed

The SSWG and NICHI argue that it is critical for the continuing survival, viability and security of the entire area to give serious consideration to a regional, economically feasible, flood risk reduction system that transcends geographical and political boundaries and that will greatly reduce the risk of flooding of the many coastal cities and suburban communities lying within its perimeter.

The groups make the bold claim that had a properly designed and located regional barrier system had been in place before superstorm Struck, there would have been no ocean flooding within the core region of protection (see first image).

Fig 1: Schematic diagram locating possible outer harbor and coastal storm surge barriers designed to protect, within the circle of protection, the all five boroughs of New York City including Jamaica Bay, many south shore communities on Long Island, northern New Jersey including Hoboken and the Meadowlands, the three major airports (JFK, LaGuardia, and Newark), Port Elizabeth and surrounding industrial infrastructure[8].

Such a regional approach is in keeping with the NYS 2100 Commission report Recommendations to Improve the Strength and Resilience of the Empire State’s Infrastructure [9], released by Governor Andrew Cuomo in January, 2013.

The report recommendations include developing “…a comprehensive resilience strategy, including a restoration plan and storm surge barrier assessment, for New York Harbor.”

In the wake of Sandy, a number of initiatives have been undertaken to reduce the risk of future flooding. Many of these have been federally-funded with post-disaster reimbursements from sources including the Army Corps of Engineers (with projects already authorized and designed, but not appropriated), FEMA, and HUD. Rebuild by Design, a HUD- sponsored competition to imagine flood risk reduction projects that would also benefit communities, attracted 148 entries.

Fig 2: The Thames River Barrier is the world’s second largest movable flood barrier [10]. It was authorized following a historic storm in 1953 that devastated much of The Netherlands and flooded large portions of south-east England. Officially opened in 1984, it has the advantage of minimizing impediments to tidal flow while maximizing daily tidal flushing of the river.

III. The Need for an Integrated Overall Plan

 State and local agencies in the Tri-State region responded quickly and efficiently to the post-disaster funding sources, resulting in projects to rebuild infrastructure and strengthen communities and provide additional protection from flooding.

But what has become clear as projects are being designed and executed throughout the region is that there is not an overall plan to tie the individual projects together. On a regional scale, this means New York City is working on measures that will protect itself without investigating impacts on New Jersey and Long Island communities, or efficiencies that could be achieved through joint projects.

Fig. 3: The MOSE barrier system presently under construction across the three inlets of the Venice Lagoon connecting to the Gulf of Venice. This illustrative design is best suited for smaller openings in tidal inlets.

On a slightly smaller scale, funding dictates that each individual project must have an “independent utility”; adjoining projects are designed as if the neighboring project were not there. There is no general agreement on design timelines or the anticipated rate of sea level rise, and no single entity to define or enforce design guidelines, so flood risk reduction projects are being designed for various, somewhat arbitrary, flood levels.

Post-Sandy disaster funding is time-limited with rules intended to ensure that design and construction occur as quickly as possible. Unfortunately, these resources have not been accompanied by parallel funding for the study and development of comprehensive solutions that would consider the region over a much longer time horizon (100-150 years). This has resulted in a large number of disconnected projects designed for different levels of resilience that protect some neighborhoods but not others.

IV. The NY/NJ Harbor & Tributaries Focus Area Study

The US Army Corps of Engineers is the federal agency designated to maintain navigable waterways around the US. It is best placed to undertake the detailed large-scale studies that are required for bi- or multi- state regional solutions. In response to the destructions wrought by Superstorm Sandy, the Corps has already published its North Atlantic Coast Comprehensive Study[11] (2015), which recommended feasibility studies for a number of areas including the NY/NJ Harbor and its tributaries.

Scoping for the NY/NJ Harbor & Tributaries Focus Area Study[12] is now under way with the states of NY and NJ being co-equal contributing partners to the Corp-led study totaling $1.5M. The scoping study is expected to be completed in about one year with coastal risk-reduction alternatives narrowed down to two or three scenarios. Once scoping is complete, the Corps can then begin the study proper which may take an additional four years to complete.

The SSWG and NICHI believe a regional approach must consider a system that incorporates offshore surge barriers of similar scale and function to those operating or under construction in London, Rotterdam, Venice, St. Petersburg and other global cities facing threats of storm surges and flooding. In the US, the recently-completed expanded barrier system in New Orleans adds to the New England barriers already in successful operation for many years in Stamford, CT, Providence, RI and New Bedford, MA. 

Storm surge barriers cannot protect forever the region from slow but accelerating sea level rise, as the gates must be kept open the vast majority of the time to allow the discharge to the ocean of the rivers that flow into the Harbor and the daily tidal flushing of contaminants out to sea.

Thus SSWG/NICHI believes that the Corps study should thoroughly investigate a regional flood protection system as the primary line of defense against storm surges, but not sea level rise.

It follows that the various local projects underway, such as raising neighborhood bulkheads, building seawalls, elevating and flood proofing public parks, subway entrances, tunnel approaches, etc would become an additional secondary system designed only to protect the region against a slowly rising sea level (estimated to be 3-6 feet by 2100) but not storm surges.

V. We call this the bifurcated or layered-hybrid solution.

This means these seawalls would need to be a fraction of the 12-15’ height of currently proposed seawalls around, for example, Battery Park and Hoboken. Such high walls in these densely populated areas are proving to be much more expensive and difficult to build, as well as being controversial as to where exactly they would be located and how much view and access to the waterfront would be lost.

VI. The SSWG and NICHI Supports Consideration of the Following Projects

  • A storm surge barrier system located offshore away from high density development across the approaches to the New York/New Jersey Harbor estuary stretching across the so-called “Sandy Hook NJ – Far Rockaway NY Transect”;
  • an upper East River barrier at the confluence of the East River with western Long Island Sound (where large storm surges generated in the Sound are often experienced which propagate down the East River, compounding flooding in the Harbor);
  • two barriers across the East Rockaway & Jones Inlets (to protect the City of Long Beach and back-bay communities);
  • two barriers across Fire Island Inlet and Moriches Inlet (to protect Great South Bay and adjacent communities). Other inlets further east (e.g., Moriches and Shinnecock) and down the Jersey Shore also need to be addressed.

VII. A Solution that protects the Region for at Least 100 years

Given the underlying urgency of providing a functional solution that will endure for at least 100 years, we recommend that studies begin immediately in various locations to scope out the most cost-effective regional system. We suggest that the Focus Area Study address issues such as:

  • the effectiveness of a regional system under various storm scenarios; how much coastal infrastructure and communities are protected from extreme storms?
  • the effect, if any, those barriers would have on storm tide levels in adjacent areas; will there be splash back from closed barriers?
  • quantifying the environmental impacts that an offshore barrier system might have; how will tidal flows, sediment transport, flushing of the harbor, fish migration and the local ecology be affected?
  • developing preliminary designs and construction cost estimates for various configurations, plus assessment of the benefits provided (cost/benefit analyses);
  • comparing costs and benefits of a large regional system versus the economies of a system of individual projects for given risk reduction scenarios.
  • Long term coastal and regional retreat scenarios if and when sea levels reach higher than 6’ from now: when might it be time to abandon the city shoreline as we know it?

VIII. The SSWG-NICHI Advocacy Campaign

The Metro NY-NJ Storm Surge Working Group (SSWG) and the National Institute for Coastal and Harbor Infrastructure (NICHI) are collaborating on an advocacy campaign to build public understanding and support for the study, design, and construction of a regional barrier system that would greatly reduce the risk of flooding of the Metropolitan urban core and the surrounding suburban communities into the next century and beyond. The SSWG provides technical support to NICHI and others working to advance these goals.

Both organizations share a common mission to educate appropriate government agencies, real estate interests, economists, finance & insurance firms and the public about a regional storm surge protection strategy for the NY/NJ Metropolitan region. We propose a comprehensive study that includes storm surge barriers with moveable gates at the ocean approaches to the NY-NJ Harbor complex. This goal and mission will continue and remains the focus of our existence.

 

 Appendix: Examples of Flooding Maps resulting from Superstorm Sandy [13].

These screen grabs were extracted from the full-region flooding map shown on the cover of this document, published by WNYC. It is no exaggeration to say that all of the flooded regions in blue would have been kept dry, safe and secure if a properly located and designed regional barrier system were in place before Superstorm Sandy hit the Metropolitan region.

 

Footnotes:

[1] https://www.nichiusa.org/

[2] https://project.wnyc.org/flooding-sandy-new/index.html#11.00/40.7378/-74.0702

[3] Bloomberg Brief, January 21, 2016.

[4] https://en.wikipedia.org/wiki/King_Canute_and_the_waves

[5] A King, Like the Mayor, Can’t Hold Back the Seas

[6] http://www.nyc.gov/html/sirr/html/home/home.shtml

[7] NY RISING: 2013 State of the State, Gov. Andrew M. Cuomo

[8] Note: The diagrams and pictures of actual barriers that are referenced in this briefing sheet must be considered as illustrative of types of barriers that have been considered or actually constructed in many other locations throughout the world. Selection of the most appropriate types of barriers and gates for NY Harbor and the region, will be studied and evaluated as part of the US Army Corps of Engineers ongoing planning processes for NY Harbor.

[9] http://www.governor.ny.gov/sites/governor.ny.gov/files/archive/assets/documents/NYS2100.pdf

[10] https://en.wikipedia.org/wiki/Thames_Barrier#History

[11] http://www.nad.usace.army.mil/Portals/40/docs/NACCS/NACCS_main_report.pdf

[12] http://www.nan.usace.army.mil/Media/Fact-Sheets/Fact-Sheet-Article-View/Article/644997/fact-sheet-new-yorknew-jersey-harbor-tributaries-focus-area-feasibility-study/

[13] https://project.wnyc.org/flooding-sandy-new/index.html#11.00/40.7378/-74.0702

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