In the Little Theater at the Westchester County Center in White Plains New York, about 150 people gathered to learn more about the New York & New Jersey Harbors and Tributaries study (NYNJHATS).
The study is a component of the North Atlantic Coast Comprehensive Study that was completed by the US Army Corps of Engineers, North Atlantic Division. Both studies will address coastal storm and flood risk to vulnerable populations, property, ecosystems, and infrastructure affected by Hurricane Sandy in the United States' North Atlantic region.
The New York & New Jersey Harbor and Tributaries study, which will include a tiered Environmental Impact Statement, is evaluating six initial alternatives, which currently are comprised of measures that address severe coastal storm risks for specific geographic regions within the study area, in addition to a no action alternative.
The six alternative concepts in the Interim Report represent scales of solutions: system-wide, or basin-wide, or site-specific coastal storm risk reduction solutions.
The alternative concepts include assumptions of the type of measures to be included for cost estimating purposes. However, the actual type of barrier, gates, and shore based measures, (floodwall vs levee, or structural vs nonstructural and nature-based features) have not yet been confirmed, nor their exact locations in the Interim Report. These refinements are anticipated for the draft report to be released in 2020.
The New York & New Jersey Harbors and Tributaries study focuses on regional resiliency in the face of growing coastal flood risk which is expected to be greatly exacerbated by sea level change in the New York & New Jersey region.
The alternative that is garnering the most attention is a proposed 5-mile seagate that would stretch from Breezy Point New York, to Sandy Hook New Jersey. The gate would be opened most of the time, and only closed during violent weather events like Hurricane Sandy and severe Nor’easters. The potential cost of the seagate is estimated to be $118 billion throughout its lifecycle, which would include operations and maintenance costs. The limited conceptual design suggests surge barrier heights may range from approximately +46 feet (NAVD 88) at the Sandy Hook–Breezy Point location down to +21-17 feet at other locations throughout the project area. Shore-based measures may range anywhere from +51 feet (NAVD) at the Jamaica surge barrier tie-in and +35 feet at the Sandy Hook-Rockaway barrier tie-in down to anywhere between +30 to +20 feet in other locations. A detailed description can be found in the interim report document.
It is important to note that design heights are subject to change as the engineering analysis is further refined leading to the next report.
What comes next?
Due to the vast scale and complexity of this study, the Corps expects it to take up to six years to complete, essentially ending around the summer of 2022. The Corps plans to have 7 more public meetings this spring to engage the public and receive comments and data from all concerned parties. The public meetings will be spread throughout the study area in New York and New Jersey.