Shorelines Engineering- Trade-offs
A variety of shoreline treatments, from highly engineered to natural, exists on the Hudson. Under this project, a series of literature reviews and studies have advanced our understanding of what alternatives exist for shoreline management given the physical conditions present along the Hudson River Estuary.
- Shoreline Restoration Alternative Analysis: Two engineering firms prepared an initial Hudson River Estuary-specific guidance document about what alternatives exist for developing soft or vegetated shorelines. The report included a review of literature on shoreline stabilization methods. Relevant methods were then used in designs at five sites. Methods included vegetated geogrids, live crib wall, brush mattresses, joint planting, and vegetated rock gabion mattresses. This work was the basis for a training workshop on soft shore alternatives in 2006.¹
- Literature Review: Andrew Rella and Jon Miller of Stevens Institute of Technology produced a comprehensive summary of published literature on engineering approaches for limiting erosion along sheltered shorelines, like those found along the Hudson River Estuary. The report describes the approaches and categorizes them according to construction and maintenance costs and whether they are adaptable to sea level rise and they range from hard to soft. For each method, design and construction information is provided, including references to engineering literature.
Ecologically enhanced engineered shoreline protection
A subset of shore protection methods that incorporates measures to attract and support both terrestrial and aquatic biota and desirable ecological functions. These can be either modifications to existing structures through the addition of plantings and other ecological measures or the design of new structures incorporating ecologically-friendly materials, geometry, or placement. If correctly designed, ecologically-engineered structures serve to prevent or reduce shore erosion while emulating the physical and biological conditions of naturally occurring, stable shorelines. Valuable ecosystem services are enhanced or restored; including provision of habitat for terrestrial and aquatic species, maintenance of water quality, aesthetic, resilience and sustainability.
Shorelines are dynamic in nature and erosion is to be expected. Not all eroding shores need to be protected or stabilized. However, landowners may want to address erosion if the shoreline experiences chronic and intense erosion, and where valuable habitat, or valuable built infrastructure are at risk. The cause of the erosion must be identified to successfully protect the shore. Erosion can occur because of: hydrological conditions (i.e. waves and currents); stormwater runoff; human interaction (i.e. structure placement or dredging); or various other reasons. Different stabilization solutions are appropriate only for a specific range of conditions and the unique characteristics at each site will dictate the selection of the optimal stabilization treatment. See Is your shoreline eroding? for more information.
Assessing Resilient Shoreline Treatments – A Forensic Analysis
A team led by the Hudson River National Estuarine Research Reserve (NERR) received funding to assess shoreline stabilization treatments in the wake of three historic storms, including “superstorm” Sandy. The team is using collaborative techniques to work with stakeholders to study why some stabilization treatments along the Hudson River Estuary were badly damaged and failed during these storms, while others survived. The project, What Made Shorelines Resilient? A Forensic Analysis of Shoreline Structure on the Hudson River Estuary Following Three Historic Storms, includes a forensic engineering analysis to determine the critical factors that contributed to each treatment’s performance in extreme weather events. The team will share findings from this project with Hudson River communities as they plan for climate change.
For more information on the Forensic Analysis please see An Analysis of Shorelines Following three Historic Storms
Tidal Hudson River Ice Climatology
Shoreline engineers planning either hard or soft engineering projects need to also consider the effect seasonal ice has on exposed structures. The Tidal Hudson River Ice Cover Climatology explains the methodology and results of the climatological and statistical analyses for the ice distributions of ice thickness and ice cover as well as ice types on the Hudson River Estuary. The winter ice season (mid-December to late March each year) brings many significant changes to the water circulation and tides in the Hudson River Estuary. Ice cover thickness is also an important engineering and design parameter for Hudson River Sustainable Shorelines. To describe ice conditions in the Hudson, Stevens Institute of Technology has collected and processed US Coast Guard (USCG) daily ice reports from the tidal Hudson River for the past 11 winter seasons [2004-2015] at 16 different stretches and ice choke points spanning some 140 miles along the river from the George Washington Bridge in Manhattan to Troy, NY.
Hudson River Wake Study
The Hudson River Wake Study was carried out to determine the wake heights produced by different vessels in the Hudson River. This study was undertaken as part of understanding the physical forces impacting shorelines in the Hudson River Estuary in order to gleam more information on critical design parameters that protect the shore. For more information on this project see the Wake Study page.
¹ Allen, G., T. Cook, and J. Young. 2006. “Hudson River Shoreline Restoration Alternatives Analysis.” Report prepared for NYS DEC and NEIWPCC by Alden Research Laboratories, Inc. and ASA Analysis and Communications, Inc.
² Rella, A. and Miller, J. 2012a. “Engineered Approaches for Limiting Erosion along Sheltered Shorelines”. In association with and published by Stevens Institute for the Hudson River Sustainable Shorelines Project
3 Rella, A. and Miller, J., 2012b. A Comparative Cost Analysis of Ten Shore Protection Approaches at Three Sites Under Two Sea Level Rise Scenarios. In association with and published by the Hudson River Sustainable Shorelines Project, Staatsburg, NY 12580, https://www.hrnerr.org.