NON ROCK ALTERNATIVE TO SHORELINE PROTECTION DEMONSTRATION
PROJECT
Jamie Bartel, Scott Bartkowski, Tom Brown and Tim Hillier
Jamie M. Bartel, CDM Smith, 445 North Blvd., Baton Rouge, LA 70802 USA
Phone: 225-663-3044, Email: barteljm@cdmsmith.com
Bio: Ms. Bartel is a Professional Geologist, licensed in four states, and an MBA graduate with 25 years’
experience in environmentally related fields and project/program management. Inspired by nature early
in life, she made it her goal to develop a career in which she could assist in protecting and/or restoring
natural areas adversely impacted by human development. Her career has and continues to accomplish
what she set out to do, and it evolves as changes and trends in the environmental-related industry are
better understood and practiced. Most recently she has been involved in coastal restoration and
navigation related projects.
The Shark Island site, located in Iberia Parish, Louisiana, was selected by USDA-NRCS for design of a
non rock alternative for shoreline protection. The shoreline at Shark Island is unique in that other means
of shoreline protection have not fully reached their potenitial and are questionable in terms of their
limitations. This project was intended to demonstrate the effectiveness of treatment for shoreline
protection—a design that can withstand settement limitations, weather storm surge, and ultimatley
protect the shoreline from further erosion. CDM Smith and Living Shoreline Solutions, Inc. (LSSI)
developed a shoreline restoration solution for this site using an innovative technology. The technology
used was Wave Attenuation Devices (WADs ®) developed exclusively by LSSI (U.S. Patent
6,186,702B1). The WADs ® are a unique design developed to both reduce shoreline erosion and
produce habitat in the most general terms and the design is flexible for various coastal situations.
The project involved analysis and design of shoreline protection along 500 linear feet of shoreline at the
site. In support of design efforts, site visits were conducted to verify field conditions and to check the
accuracy of the bathymetric surveys. The design process began with geotechnical analysis to determine
settlement over a three-year test period and to show that the WADs® would maintain an elevation of 1-2
feet above mean high water post construction. The most significant design challenge using the WADs®
system was settlement of the structures in very soft, peaty offshore substrate along the shoreline. Wave
and water level analysis along with structural analysis was completed to demonstrate that the WADs®
could withstand the calculated wave forces without overturning. An iterative design approach was used
in developing the final WAD® unit design and WADs® system configuration, based on geotechnical
analyses that determined maximum load bearing capacity, and minimum settlement. The final design
package was completed within 75 days as required by NRCS.
Each unit is 7-feet in height and 10-feet across at the base, and each unit included a sacrificial concrete
base (2.5 feet in height) to account for settlement, and to maintain the ability to mitigate shoreline
erosion by dissipating 90% of the regional wave energy. The array of WADs® was fully constructed in
March 2014, and consisted of 155 WADs® placed side by side, parallel to the existing shoreline, base to
base, giving the units increased stability and providing WAD® array integrity. After mobilization and
manufacturing, installation of the WADs® was completed in 6 days using an excavator loaded barge;
one WAD® every four minutes.