Living Shoreline at Slade Dale Sanctuary

As one of only a few areas of open space left in Point Pleasant, the 13-acre Slade Dale Sanctuary is an important part of the local ecosystem, and is home to a number of unique animals and plants. This waterfront preserve along the North Branch Beaver Dam Creek is predominantly tidal marsh, which provides habitat for various birds, including osprey, as well as passive recreation opportunities for the community.

Unfortunately, the Slade Dale Sanctuary is disappearing. Since 1930, the shoreline of Slade Dale Sanctuary has retreated approximately 300 feet, equal to the length of a football field, and the channels into the marsh have increased in number and size, according to aerial imagery that Princeton Hydro assessed on behalf of American Littoral Society.

In order to stabilize the shoreline, restore the marsh, and enhance the ecological function and integrity of the preserve, American Littoral Society contracted Princeton Hydro to develop a conceptual and engineering design using living shoreline features to enhance ecological value and reduce erosion. To develop a final design, Princeton Hydro mapped historic wetland extents, performed a bathymetric survey, as well as an ecological and engineering assessment of the waterfront.

The final concept utilized a novel, low-cost technique that had never been done in New Jersey – upcycling donated Christmas trees into a living shoreline. The design used a combination of breakwater fence and tree vane structures to attenuate wave action, foster sediment accretion, and reduce erosion along the shoreline. The tree vane structures are located behind the 1977 Tidelands Line to comply with state regulations. Both types of structures mimic naturally occurring debris structures in tidal systems and enhance habitat opportunity and shelter for aquatic life.

To implement this design the trees were transported by volunteers from their staged locations on the marsh to the breakwater sections that were previously installed in the water. The trees were stuffed between the pilings, securely tied down, and staked directly into the creek bottom.