Appendix_Guidance_for_Installing_Living_Shoreline_Projects.pdf

Guidance for Installing Living Shoreline Projects

The following guidance is intended to provide the most up to date information to project managers constructing living shorelines. The information will vary depending on time of project and/or other factors. This information is intended to be used as a reference for building living shoreline projects in coastal Georgia and does not relieve the reader of any obligation or responsibility for obtaining and complying with the provisions of local, state, or federal laws.

Shell suppliers

Company Location Phone Cost/Bushel without transport

Cost/Bushel with transport

Year

Lloyd’s Oyster House

Shallotte, NC (910) 754-6958 $1.00 $2.20 2010

Green’s Oyster Company

Shallotte, NC (910) 579-2241 $1.25 $3.80 2012

Webb’s Seafood

Youngstown, FL

(850) 722-9598 $1.08 --- 2012

Bluffton Oyster Company

Bluffton, SC (843) 757-4010 $8.00 or $4.00/cubic yard if ordered in large quantity

--- 2014

Mesh Bagging to consolidate shells

Duronet ¾” mesh bags are used to consolidate oyster shell. One supplier of the mesh material is Delstar Technologies, Inc. (www.delstarinc.com). The contact information as well as the product information is below.

Item number: 113311

800.531.5112 x 1151 1000’ rolls will make approximately 333 bags.

2000’ rolls will make approximately 666 bags.

Shipping is an additional cost.

http://www.delstarinc.com/

Method to bag shell and placement of bags on shoreline

Mesh material should be cut to 36” segments. Tie a pigtail on one end (leaving as little mesh in pigtail as possible), fill with shell, and tie at opposite end. Each bag should weigh around 15 pounds. Heavier bags are difficult to lift and place while smaller bags will dislodge and move along the shoreline. Bags should be placed in a position perpendicular to the shore to avoid rolling into creek. Depending on tidal velocity and slope, bags may need to be secured with J-hook rebar.

Bagging material is cut to 36” segments, tied at the end, filled with oyster shell, and tied at opposite end.

Oyster bags are placed perpendicular to the shoreline or vegetation to prevent rolling into adjacent tidal creek.

Placement of bags along Shoreline

The slope of the shoreline will dictate the placement of bags, number of bags, and need for reinforcement through the installation of a rock toe. At any slope, it is important to note that shell will only recruit oysters when placed between MLW and MHW. In order to place material where recruitment potential is highest, the surrounding tidal creek bank at the project site should be surveyed to determine presence of live oysters. If oysters are present, the elevation of those reefs should be determined and mimicked at the construction site.

Gradually Sloped Banks

At sites with very gradual slopes (approximately less than 1:3 rise:run), CRD has placed (planted) oyster bags approximately 96” wide along shorelines. If the sediment is not firm (i.e. silty muds), pallets may be placed on the mud surface in order to provide relief for oysters to recruit, therefore minimizing potential for sedimentation of the surface layer of shell.

Below are schematics of project installation on low sloping shoreline banks. Note the importance of placement of material in comparison to MHW and MLW.

Steeper Sloped Banks

Placement of materials on steeper slopes will likely require a rock toe (slopes of approximately 1:3 or greater). A geotextile is placed on the sediment surface to prevent further erosion. Oyster bags are placed directly on the geotextile, either as one layer, or two, depending on the site. Below are two drawings to show placement of bagged material on steeper sloped projects. Contact an engineering firm for more detailed information when constructing steeper sloped living shoreline projects.

GA DNR Coastal Resources Division, Updated October 2015