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Project Plan for the Living Shoreline Demonstration Project at Cedar Beach County Park, Southold, New York

The proposed Living Shoreline Demonstration Project is a cooperative arrangement between the Peconic Estuary Program and Cornell University Cooperative Extension (CCE) to provide physical examples of various options to be used in place of full-scale bulkheads and similar hardened structures, in appropriate locations, to protect residential shorelines. The benefits of living shoreline techniques over traditional shoreline hardening methods include lower installation and maintenance costs, maintaining/creating natural salt marsh habitat, adaptability to natural forces and sea level rise, and maintaining/creating the natural shoreline aesthetic. The goal of this project is to create centralized location where local and regional government agencies (e.g., Town Trustees and NYSDEC) can direct the public to view and learn about alternatives to traditional shoreline hardening methods.

The Living Shoreline Demonstration Project will be located in Cedar Beach County Park, Southold, New York. The demonstration site is located along the shores of a dredged canal behind the Suffolk County Environmental Learning Center, operated by CCE (see attached figures. The shoreline includes small, intermittent patches of smooth cordgrass (Spartina alterniflora), which, under recommendation from NYDEC Marine Bureau personnel, would be incorporated into the demonstrated living shoreline techniques. As illustrated in the accompanying figures, a total of five (5) demonstration “plots” will be installed along the project area’s shoreline. As cordgrass generally occupies the intertidal from mean sea level (MSL) to mean high water (MHW), the natural hardening materials, as described below will be installed just subtidal of MSL. Where cordgrass exists in a demonstration plot, the structural material will be placed just below the existing line of plants (considered MSL). For unvegetated sections of plots, adjacent stands of cordgrass will be used as biological benchmarks and MSL will be marked out on an incoming tide as the water’s edge reaches the base of the adjacent cordgrass. For this project, no cordgrass, or other vegetation, will be removed in the creation of the demonstration plots. Unvegetated areas within the demonstration plots (between MSL and MHW) will be planted with cordgrass propagated by CCE from seeds collected from Cedar Beach Creek and maintained in CCE’s restoration nursery.

Demonstration Plot Descriptions

This project proposed the creation of five (5), 60’ long demonstration plots along the shoreline of a dredged canal in Cedar Beach Creek. All of the demonstration plots will incorporate natural material to provide a “hardened” component along the seaward edge of the plots, backed by a vegetated component (cordgrass) extending from MSL to MHW. None of the proposed “hardened” structures will extend above the sediment surface by more than 2’ (24”). Any unvegetated areas upland of the “hardened” structures, will have cordgrass plugs planted at 1’-on-center spacing, up to MHW.

The five methods to be demonstrated by this project are described below.

1) Coir/Coconut Fiber Logs – Coir logs are commonly used for erosion control in shoreline projects. Coir logs consist of interwoven coconut fibers encased in a natural, hemp net casing. Coir logs are biodegradable, but are resilient enough to provide at least 2 years of stabilization before breaking down. Typically, this is enough time to establish a band of vegetation behind the logs, which will provide the erosion control once the coir logs have degraded. The coir log demonstration plot will have five (5), 12’-long by 1’-diameter logs deployed just below MSL. Coir logs are typically anchored in place with wooden stakes. The stakes are either driven through the middle of the coir log or are placed in pairs (seaward and landward of the log), sandwiching the log. The coir logs for this project will use the single stake method, due to the sheltered nature of the project location.

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2) Shell Bags – Shell is a naturally occurring marine material that has been extensively used for creating subtidal reefs for oyster productions and shoreline protection. Shell used for these types of projects is aged on land to allow any tissue to decay reducing the risk of potentially transmitting disease or creating an attractive nuisance from scavengers (i.e. gulls, raccoons, crabs) when the shell is placed back in the marine environment. The shell bags to be used for this demonstration project will include mixed (oyster, hard clam, and surf clam), aged (6 months) shell, loaded into biodegradable mesh bags. The shell bags will be 2’-long by 1’-diameter and deployed seaward of MSL, stacked with a two bag base and a single bag on top. Due to the weight of the shell bags, there will be no anchoring methods (i.e. staking) required.

3) Rock – Rock has been used for shoreline protection at all scales. For the demonstration project, small rock 4-12”-diameter will be used to create a small, rock “breakwater” just below MSL. The rock would be installed in a similar fashion to the shell bags, with a wide base (< 3’ wide) and tapering toward the top (≤ 2’ high). Placement of the rock along the 60’ length of the demonstration plot will be completed by hand and no anchoring method will be required.

4) Single, Natural-Wood Terrace – Terracing has been used for thousands of years to stabilize slopes. Conventional bulkheads are basically a single tier terrace, and the method described below is similar to a “low-sill” bulkhead. For this demonstration project, it is proposed to construct a single-tier, wooden terrace constructed from natural, native wood logs. Two species of trees grow locally that are highly resistant to rot, even in wet conditions, and are relatively abundant, locally: black locust (Robinia pseudoacacia) and eastern red cedar (Juniperus virginiana). The Town of Southold owns several preserved lands that have a number of windthrown black locust trees that could be used for terrace material. These black locusts would be preferable to cedar as locating dead or windthrown cedar is more difficult and the project would prefer not to cut down living material. The wood material would be cut to manageable lengths and used to create a single terrace, no more than 2’ high by 1’ wide. The logs would need to be secured in place with wooden stakes/posts, and smaller diameter sections of the logs could be used. The posts would be driven into the shoreline, by hand, at least 3’deep and the horizontally-placed log terrace would be secured to the posts with galvanized hardware.

5) Double, Natural-Wood Terrace – This method would be constructed in a similar fashion to the single, natural-wood terrace detailed above, with the exception of the height and number of terraces. This demonstration plot will include a section of the canal shoreline that has a steeper slope than the other plot areas, and will serve as an example of a technique that can be used in similar circumstances. The two terraces will consist of shorter walls, approximately 1’ high, anchored by wood posts and galvanized hardware in the same manner as detail above. The lower terrace will be located just below MSL, with the second terrace installed approximately halfway up the shoreline between MSL and MHW. The double terrace plot is located on a stretch of shoreline that is unvegetated, and cordgrass plugs will be planted into the plot area at 1’-on-center.

Ribbed Mussel (Geukensia demissa) Propagation and “Planting”

Another proposed aspect of this project is to develop an efficient and reliable methodology for spawning and raising ribbed mussels for shoreline restoration projects. Ribbed mussels are an integral part of the salt marsh complex, providing resilience to the seaward edge of the marsh, improving water quality through filter-feeding, and acting as a food source for a number of animals. While shellfish like oysters could provide much of the same services as the ribbed mussel, and their propagation is well documented, their use as a component of living shorelines is complicated due to their value as a human delicacy. This is especially problematic in areas where coastal waters are impaired and shellfish harvest/consumption is prohibited. Ribbed mussels do not

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present this permitting challenge as they are not a target food item.

CCE plans to continue developing a methodology to spawn ribbed mussels, raise the mussels to an appropriate size for release, then incorporate them into the living shoreline demonstration plots, detailed above. Reported attempts at transplanting ribbed mussels harvested from natural populations for restoration purposes has met with mixed success in the past. Setting ribbed mussels in place at an earlier stage in their life may result in higher success rates. To test this hypothesis, CCE will collect natural-occurring ribbed mussel from Cedar Beach Creek to be used to compare the success of establishing hatchery-raised mussels versus transplanted mussels into living shoreline design. The collection of natural-set ribbed mussels for research should be cover by a Scientific License to Collect or Possess (LCP), and CCE maintains an LCP, which will be amended for 2019 to include collection of ribbed mussels.

Cedar Beach Road

1 inch = 100 feet ¯ Legend

Proposed Project Areas

Location: Cedar Beach County Park 3690 Cedar Beach Road Southold, NY 11971

Date Prepared: 11/27/2018

Prepared By: Stephen Schott Cornell University Cooperative Extension, Habitat Restoration Specialist

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● ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !

Single, Wood Terrace Treatment

Canal

Proposed locations of demonstration areas, each consisting of 60' sections of shoreline and presenting different materials (labeled and as detailed in plans) to provide stability to shore.

Coir Log Treatment Shellbag Treatment MLW

Location: Cedar Beach County Park 3690 Cedar Beach Road Southold, NY 11971

Date Prepared: 11/27/2018

Prepared By: Stephen Schott Cornell University Cooperative Extension, Habitat Restoration Specialist

Wetland Delineation: Date Completed: 10/1/2018 Completed By: Chris Pickerell Cornell University Cooperative Extension Wetland Specialist

¯

1 inch = 25 feet

Legend Buildings

Bulkheads

● ! Fence

Existing Spartina

Phragmites

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Permeable root barrier

Conceptual Diagrams of Proposed Living Shoreline Demonstration Project Treatment Plots - Coir (Coconut) Fiber Logs

Coir Fiber log

Coconut Fiber Log

Spartina

Wooden stakes 60ft

MHW

MSL

MLW

MLW

Coconut Fiber Log

Spartina

1’ MSL

Coir fiber log 1’

Wooden stake

Phragmites

MHW

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Conceptual Diagrams of Proposed Living Shoreline Demonstration Project Treatment Plots - Shellbags (Oyster/Clam)

Shell Bags

Shell Bag Breakwater

Spartina

60ft

MHW

MSL

MLW

MLW

Shell Bag Breakwater Mound

Spartina

2’

MSL Shell bags (one row over two)

2’

MHW

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Conceptual Diagrams of Proposed Living Shoreline Demonstration Project Treatment Plots - Rock

Rocks

Rock Breakwater

Spartina

60ft

MHW

MSL

MLW

MLW

Rock Breakwater

Spartina

2’

MSL Rock pile

<3’

MHW

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Conceptual Diagrams of Proposed Living Shoreline Demonstration Project Treatment Plots - Double, Wood (Locust/Cedar Log) Terrace

Natural Wood Terrace

Spartina

Wooden logs

MHW

MSL

Wooden stakes

60ft

MLW

Natural Wood Terrace

Spartina MHW

2’

MSL

Wooden logs 1’

MLW

Wooden stake

*Using locust or cedar logs and stakes

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Conceptual Diagrams of Proposed Living Shoreline Demonstration Project Treatment Plots - Single, Wood (Locust/Cedar Log) Terrace

Natural Wood Double Terrace

Spartina

Wooden logs

MHW

MSL

Wooden stakes

60ft

MLW

Natural Wood Double Terrace

Spartina MHW

MSL

Wooden log

1’

1’

1’ Wooden log

1’

MLW Wooden stake

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