“The waters around you have grown” – Bob Dylan

By A. Michael Pappalardo, RPA

Archaeologist, AKRF, Inc.

This blog post provides a summary of two current Hurricane Sandy-related coastal resiliency efforts we are completing in the highly urbanized environment of New York City. They both involve the range of methods typically used to identify and resolve adverse effects to cultural resources in urban settings, with the additional challenge of the resources being off-shore, submerged, or deeply-buried.

East Side Coastal Resiliency, Manhattan, NY

In 2012, Hurricane Sandy unleashed extreme flooding in Lower Manhattan and made abundantly clear the need to increase coastal resiliency to reduce flooding and improve coastal and social infrastructure. To address these needs, the City of New York is creating a comprehensive flood protection system (the East Side Coastal Resiliency project, or ESCR), which comprises a combination of landscaped berms, floodwalls, and deployable elements along a 2.2-mile stretch of the Manhattan’s Lower East Side. In addition to providing reliable flood protection, the proposed project would also improve access to and enhance open space resources including parks along the waterfront. To help implement the project, the City is entering into a grant agreement with the U.S. Department of Housing and Urban Development (HUD) to accept $335 million in Community Development Block Grant-Disaster Recovery Funds (CDBG-DR), triggering two federal-level environmental review processes, the National Environmental Protection Act (NEPA) and the National Historic Preservation Act (NHPA).

AKRF leads both the design and environmental review teams tasked with examining the potential for impacts during the project’s 5 years of construction on such areas as open space and parklands, streets and pedestrian circulation, land use, visual corridors and urban design, natural resources, infrastructure systems, architectural resources, and, through our subconsultant Historical Perspectives, Inc. (HPI), archaeological resources.

As with many cities along the eastern seaboard, Manhattan expanded from the late 17th through 20th centuries through filling in development lots along the coastline, a practice that can both bury and create archaeological features. Of late, we have become increasingly aware that these landfilled coastal areas are frequently the most vulnerable to the destructive forces of climate change. HPI reviewed cartographic and documentary resources, evaluated modern disturbance impacts, and examined soil boring logs to determine the project’s potential effects to archaeological resources. Their assessment considered the project site’s sensitivity for the following potential historic resources:

  • Bulkheads
  • Buried river bottom remains
  • Sunken vessels
  • Landfill-retaining structures
  • Wharves and piers
  • Drydocks
  • Primary and secondary landfill deposits
  • Land transportation elements

Given the massive scale of the survey required to determine the presence or absence of these deeply buried resources in a busy city that famously never sleeps, archaeological monitoring will be completed during the construction phase to document resources that cannot be avoided.

Living Breakwaters, Staten Island, NY

Staten Island is located at the very crux of the New York Bight, the huge funnel formed by the coastlines of Long Island and New Jersey. This southernmost New York City borough suffered more direct damage from Hurricane Sandy’s storm surge than any other. The Living Breakwaters project is one of the six winners of the HUD-sponsored Rebuild by Design, a competition that promotes projects that address the structural and social vulnerabilities exposed by Superstorm Sandy. The project will strategically place a series of house-sized concrete blocks offshore to reduce wave energy, promote calm water, and reverse shoreline erosion. The breakwaters will also foster ecological resiliency by providing a structural habitat for a diversity of marine species and are designed to work in concert with an on-shore dune system to further reduce risk to the shoreline community.

New York State was allocated $60 million of HUD CDBG-DR funds to implement the first phase of the project, and AKRF is preparing the environmental review for the project in accordance with NEPA and NHPA. Soon after starting our work, it became clear that the offshore geotechnical sampling required to design this project would provide an excellent opportunity to test the conclusions of the U.S. Army Corps of Engineers’ assessment of New York Harbor’s submerged paleoenvironment. The study, completed by Geoarchaeology Research Associates, Inc. (GRA) in 2014, identified the portion of Staten Island’s coastline where the Living Breakwaters will be constructed as one of New York City’s very few areas of high sensitivity for the preservation of formerly habitable but now submerged paleolandforms in the harbor.

The geomorphological survey, completed by Kerry Lynch, Ph.D., of the University of Massachusetts, consisted of monitoring and systematically sampling a transect of offshore soil borings. Even though the sampling methods employed for the geotechnical survey were sub-optimal for geomorphology (i.e., there was discontinuous sampling and inconsistent recovery), Dr. Lynch made some interesting discoveries. Upon close examination of the soil profiles and analysis of the botanical and faunal remains recovered through soil flotation, she identified several borings with discrete stratigraphic deposits that contained terrestrial botanical material (such as charred knotwood seeds and oak and pine material) but which did not contain marine flora or fauna. These deposits were situated between overlying post-inundation marine clays and underlying pre-inundation glacio-fluvial sands, which means that Dr. Lynch had likely discovered traces of the former coastline before the dramatic sea level rise that followed the end of the last ice age.

It is certainly ironic that this possible evidence of a submerged habitable paleoenvironment was discovered only thanks to a resiliency project intended to address the effects of sea level rise and inundation on Staten Island’s contemporary residents.