New Jersey, like other coastal states, has been losing coastal wetland habitats to a combination of subsidence, erosion and sea level rise. The New Jersey Department of Environmental Protection received a grant from the National Fish and Wildlife Federation to address this issue and rejuvenate these critical habitats. Grantees were charged with providing increased resilience to natural infrastructure that will in turn increase the resiliency of coastal communities in the face of future storms like Hurricane Sandy.

As a consultant for GreenTrust Alliance, a land conservancy holding company, Princeton Hydro worked with several project partners, including NJDEP, the US Army Corps of Engineers, NJDOT, The Wetlands Institute, and The Nature Conservancy, to increase the marsh elevation to an optimal range where vegetation, and the wildlife that depends on it, can flourish. One of the techniques used for this project included the use of dredged material disposal placement, which involves using recycled sand and salt dredged from navigation channels to boost the elevation of the degraded marsh.

A media statement from NJDEP further explained the process, “sediments dredged from navigation channels and other areas are pumped onto eroding wetlands to raise their elevations enough to allow native marsh grasses to flourish or to create nesting habitats needed by some rare wildlife species. Healthy marshes with thick mats of native grasses can cushion the impact of storm surges, thereby reducing property damage.”


The salt marsh at the Fortescue project site is part of the Fortescue Wildlife Management Area. The specific goal of the project was to restore and enhance the interior high and low marsh, coastal dune and beach habitats.

To achieve these habitat enhancements, the Princeton Hydro project team first established biological benchmarks of each targeted habitat type and evaluated them to determine the upper and lower elevational tolerances for target communities and plant species. Approximately 33,300 cubic yards of dredged materials were used to restore a degraded salt marsh, restore an eroded dune, and replenish Fortescue Beach. The eroded dune was replaced with a dune designed to meet target flood elevations and protect the marsh behind it against future damage. The dune was constructed using dredged sand, and, to prevent sediment from entering the waterways, a Filtrexx containment material was used.


This project site is a tidal marsh complex located within a back-bay estuary proximal to Stone Harbor and Avalon. Princeton Hydro and project partners aimed to enhance the marsh in order to achieve the primary goal of restoring the natural function of the tidal marsh complex.

Two main activities were conducted in order to apply the dredged material to the impaired marsh plain: 1.) the placement of a thin layer of material over targeted areas of existing salt marsh to increase marsh elevations, 2.) the concentrated placement of material to fill expanding pools by elevating the substrate to the same elevation as the adjacent marsh. In total, dredged material was distributed among eight distinct placement areas throughout the property’s 51.2 acres.

These coastal wetland restoration activities will help to prevent the subsidence-based marsh loss by filling isolated pockets of open water and increasing marsh platform elevation. In addition, the beneficial reuse of dredged material facilitates routine and post-storm dredging and improves the navigability of waterways throughout the U.S.

NJ Audubon undertakes $470G study of climate change impact on wetlands

Princeton Hydro is proud to be a partner on this incredible project

If you’ve ever gone birdwatching at any east coast wildlife refuge, then you probably understand the value of coastal impoundments. These man-made wetland habitats are contained by embankments and have gates that allow managers to manipulate water levels. In addition to being valuable, these structures are also very vulnerable to sea level rise and extreme weather.

Through a $470,000 federal grant, the New Jersey Audubon is implementing an initiative to study the vulnerability of these impoundments to climate change induced environmental impacts. Funded by the U.S. Department of the Interior via the National Fish and Wildlife Foundation, the Coastal Impoundment Vulnerability and Resilience Project (CIVRP) aims to map and catalog all state, federal, and privately owned coastal impoundments from Virginia to Maine. The project is a cooperative effort of a diverse team of partners including researchers from New Jersey Audubon, National Wildlife Federation, Conservation Management Institute (Virginia Tech), U.S. Fish and Wildlife Service and Princeton Hydro.

The CIVRP will ultimately reduce climate vulnerability and enhance the natural ecosystem function of these precious and treasured wetland habitats. Read the full article from MyCentralJersey.

Princeton Hydro specializes in the restoration, creation and enhancement of tidal and freshwater wetlands. Contact us to learn more, and read about some of our award-winning wetland-related projects here.