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.

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.

[3][4] 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.

[5] 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.

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.

[7][8] 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.

[10][11] 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.

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.

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.

"[24][25][26] 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.

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.

[33][34][35] 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.

While these proposed solutions should be included in local responses because they can reduce wave action slightly, reinforce presently fragile wetlands and in some cases improve water quality, the reality is that they would be simply overwhelmed by storm surges of the magnitude experienced during Sandy.

To solicit comments on the choice of Alternative 3B as the Tentatively Selected Plan (TSP), the Corps has released a GIS-based summary,[61] a slide presentation,[62] and meeting posters.

[58] In response, the Storm Surge Working Group has published a comprehensive layered flood defense strategy,[63] including a critique of the Corps' TSP.