ORIGIN: THE REBUILD BY DESIGN COMPETITION
Risk Reduction: address both event-based and long-term shoreline erosion in order to preserve or increase beach width; attenuate storm waves to improve safety and prevent damage to buildings and infrastructure.
Ecological Enhancement: Increase the diversity of aquatic habitats in the Lower New York Harbor / Raritan Bay (e.g., oyster reefs and fish and shellfish habitat), particularly rocky / hard structured habitat that can function much like the oyster reefs that were historically found in this area.
Social Resiliency: Provide programming that builds a community around education on coastal resiliency and ecosystem stewardship; foster and encourage community stewardship and citizen science, and increase physical and visual access to the water’s edge and near-shore waters for recreation, education, research, and stewardship activities.
1. US Army Corps of Engineers, Port Authority of NY & NJ, and NY-NJ Harbor Estuary Program: Hudson-Raritan Estuary Comprehensive Restoration Plan - Version 1.0, June 2016, p. 101.
- Living Breakwaters: Approximately 2,400 linear feet of near-shore "breakwaters," or partially submerged rubble mound structures located between 790 and 1,800 feet from shore, designed not only to reduce risk, but also to provide habitat enhancements through the specialized design of the breakwater structures and the materials used.
- Shoreline Restoration: One-time placement of sand along approximately 800 linear feet of shoreline from Manhattan Street to Loretto Street where the distance between the shore and the buildings is most narrow and subject to erosion, restoring the beach to the approximate width it was in 1970s.
- Active Oyster Restoration by the Billion Oyster Project: This will include installations on the breakwaters themselves, as well as off-site oyster cultivation activities (hatcheries, remote setting, etc.), shell collection and curing.
- Programming: This includes educational, stewardship, and workforce training activities related to the other project elements.
Building Physical Resilience
The breakwaters are designed to reduce wave energy and reduce or reverse shoreline erosion in the project area. Extensive modeling efforts were performed to understand the impacts of the breakwater system on shoreline change in order to maximize risk reduction and erosion benefits while minimizing negative environmental and aesthetic impacts. The breakwater system has been designed to capture sediments along the shoreline, reducing historic shoreline erosion and in most places widening the beach over time. This wider beach will provide additional protection from erosion and wave action to on shore coastal protective features and other assets.
The breakwaters are designed to provide habitat and support biologic activity consistent with existing regional plans and priorities such as the Hudson Raritan Estuary Comprehensive Restoration Plan (HRE CRP) and generate net ecosystem benefits in the project area. Contrary to traditional rubble mound breakwaters, which often offer less diverse biological niches when compared to natural rocky shorelines (Chapman and Bulleri 2003, Burt et al. 2009), the Living Breakwaters are designed to avoid and minimize negative impacts and optimize habitat creation and ecosystem services. To avoid critical habitats, and to reduce the structures overall footprint, the Living Breakwaters are designed with minimized crest widths and reduced crest elevations where this is consistent with the project’s risk reduction goals. Steeper side slopes allow for a smaller footprint for the main breakwater while still being structurally sound and providing opportunities for ecological enhancement on surfaces within the intertidal and subtidal areas. The use of multiple breakwaters with small gap widths rather than long, continuous breakwaters also helps to reduce footprint sizes while creating additional habitat variety between the ends of the breakwaters. Closely spaced rocky intertidal / subtidal protrusions (reef fingers) create “reef streets” which add habitat complexity and dramatically increase the length of productive edge habitat. The integration of bioenhancing concrete units into the armor units of the main body of the breakwater segments as well as the reef streets adds greater range of crevice sizes and promotes biogenic buildup to further enhance the overall complexity and variety of the rocky habitat created. This further contributes to greater biodiversity and overall biological activity on and around the breakwaters. The inclusion of active oyster restoration on and around the breakwaters will provide additional variety and micro-complexity to the structure’s habitat, as well as help to achieve regional restoration goals (HRE CRP). Together, these strategies help the project maximize the ecological uplift provided and help offset any impacts to existing habitats or species. The following section provides a summary of the habitat benefits and potential impacts provided by the breakwaters.
Fostering Social Resilience
The calmed near shore waters and wider beaches created by the breakwaters will not only help reduce risk from coastal storms, but will also enhance recreational opportunities along the shoreline including boating, fishing, and general beach use.
The Billion Oyster Project has also developed a Living Breakwaters STEM Curriculum designed for students in 6th to 8th grade public school science classes, emphasizing the history and importance of oysters to Staten Island and its ecology, and showcasing the Living Breakwaters as a case study in coastal resilience. The curriculum explains how the breakwaters will increase the area’s resiliency and how they will contribute to a healthier environment. In 2019, BOP worked with teachers in more than a dozen schools in Staten Island and nearly 50 city-wide and plans.
The breakwaters consist of a series of nine ecologically enhanced breakwater segments off the southwestern tip of Staten Island. Made of a combination of hard stone and ecological concrete units, the breakwaters are non-traditional rubble mound structures. The system, with final design completed in early 2019, has been designed to reduce or reverse erosion (grow beach) and reduce coastal storm risk through wave attenuation. A network of ecological enhancements integrated into the breakwater’s physical structure (“reef streets” and “reef ridges” and water retaining elements) and targeted material selection (bio-enhancing concrete) are aimed to increase biodiversity by providing various ecological niches and improving the ecosystem services provided by structures. The project also proposes to include eastern oyster (Crassostrea virginica) active restoration on and within the breakwaters and placement of “spat” (juvenile oysters) attached to shells.
The breakwater system will include approximately 2,400 linear feet of breakwaters. The breakwaters will be located between 790 and 1,800 feet from shore and in water depths of between two-and-10 feet below mean low water (NAVD88). In addition to the breakwaters themselves, the design includes a limited, strategic, one-time placement of shoreline restoration that will add needed sediment to the system and provide initial protection to the most vulnerable stretch of beach as the breakwaters work over time to accrete beach elsewhere.
This layout was refined through the process of design and computer modeling, where scenarios were iteratively developed, modeled to evaluate impacts on shoreline change and storm wave attenuation, and the results analyzed to help inform the design refinement.
The breakwaters will be primarily constructed as rubble mound (rock) structures with a stone core, a marine mattress layer to protect against scour, and outer layers consisting of armor stones and ecological concrete armor units. In the subtidal and intertidal areas, approximately a third of the outer layer of stone armor units will be replaced with ecological concrete armor units. These ecological concrete units are structural armor units specially designed to promote biological activity and promote recruitment of marine species. This is achieved through both the specialized concrete mixture and the design of the textured surfaces of the units.
In addition to the main (traditional) breakwater segment, the Living Breakwaters will have “reef ridges”—rocky protrusions on the ocean-facing sides of the breakwaters—and “reef streets”—the narrow spaces between the reef ridges. These features will create localized modifications to wave behavior and provide a diversity of habitat characteristics to generate opportunities for species recruitment and ecological enhancement. Habitat diversity will be further enhanced on the reef ridges through greater variation in rock sizes and the interspaces between them, the textured surfaces of the ecological concrete armor units, and the inclusion of ecological concrete tidepools in the intertidal zone.
The Living Breakwaters function as a system of elements that work together to reduce risk and enhance habitat in the Raritan Bay. Each segment was individually designed to contribute to the overall system and achieve the desired performance in the project area. The breakwaters’ distance from shore, segment lengths, the width of the gap between segments, orientation, and crest height were refined in the final design to optimize wave attenuation performance and reduce or reverse shoreline erosion in line with the project goals.
Active Restoration: Oyster Installations
Active oyster restoration on and adjacent to the breakwaters will further enhance the habitat opportunities created by the breakwaters. Techniques will include the incorporation of spat placement into a small percentage of the ecological concrete units, the use of oyster shell gabions (non-structural units), spat on shell placed in the reef streets and adjacent to the breakwaters, and in-situ setting pilots. The oyster gabions will use the same design being employed in other oyster restoration projects in locations in the Harbor as part of the Hudson Raritan Estuary comprehensive restoration plan, spat on shell techniques will be based on techniques developed and deployed during the Oyster Restoration Research Project. Oyster restoration will be implemented by the Billion Oyster Project.
NEXT STEPS: PROJECT SCHEDULE
Plans for Construction
Living Breakwaters is currently in the Procurement process. Please check back for an updated construction schedule.
The Environmental Impact Statement (EIS) process was completed in mid-2018 with the publication of the Joint Record of Decision and Finding Statement of the Coastal and Social Resiliency Initiatives for Tottenville. It can be found on the Storm Recovery website (Click Here) by scrolling down to the Rebuild by Design section. The Project also requires permits from the US Army Corp of Engineers and the New York State Department of Environmental Conservation.
The budget amount submitted in the overall design proposal to the RBD Competition for the Living Breakwaters Project was approximately $74 million. When selected for funding, the project received a Community Development Block Grant- Disaster Recovery (CDBG-DR) allocation of $60 million. The State of New York has allocated $14 million of capital budget funding to augment the federal funds.
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