NYSDEC Wetland Monitoring – Old Place Creek Mitigation Site

The Goethals Bridge Replacement Project resulted in unavoidable impacts to 4.929 acres of wetlands and open water associated with the Arthur Kill, requiring the creation of 15.39 acres of mudflat, low marsh, high marsh, and scrub/shrub habitat; and preservation of 3.91 acres of existing low marsh/high marsh and open water habitat. Princeton Hydro worked with the United States Army Corps of Engineers (USACE) – New York District and the New York State Department of Environmental Conservation (NYSDEC) on the development of an acceptable monitoring program that was implemented in 2019. As stipulated in the NYSDEC-issued permit, the monitoring program had to follow the New York State Salt Marsh Restoration and Monitoring Guidelines (Guidelines) established in 2000. Working closely with USACE and NYSDEC and following the program specified within the Guidelines, Princeton Hydro established five transects and eighteen associated 1m2 quadrat locations along the five transects. Each transect represented a cross section of the various ecological communities present between Old Place Creek and the upper extent of the mitigation site. The ecological communities monitored across each transect included low marsh, high marsh, transitional zones between low marsh and high marsh, and scrub/shrub, respectively.

The following metrics were calculated within each 1m2 quadrat: overall percent cover and species composition comprising the observed percent cover. Within each 1m2 quadrat, a 0.25m2 portion of the quadrat was analyzed for stem density and plant height as outlined within the Guidelines. Additionally, the entire mitigation site was investigated for the presence of invasive species with subsequent mapping developed and incorporated into an adaptive management plan. This was then implemented to address the presence of common reed (Phragmites australis). Annual monitoring reports were prepared and submitted to both USACE and NYSDEC detailing the results of the monitoring effort with a focus on the established transects and 1m2 quadrats along each transect. A section of the reports was dedicated to the development of an adaptive management plan to ensure the mitigation site satisfied the requisite 85% vegetative cover comprised of desirable, native species.