HomeMy Public PortalAbout140_020_DOC102016-10202016144526.pdfThe Tybee Island Beach Management Taskforce has determined that a substantial, healthy, and
continuous array of sand dunes on our front beach is critical to Tybee Island. Significant erosion occurs
on the beach on a daily basis. Storms and certain other weather events accelerate this erosion. The
goals here are to protect life and property on Tybee and to hold sand on our beach much longer. It is
vital that Tybee develop a system of dune stabilization and dune building that is far more efficient and
effective than previous techniques employed at Tybee.
After considerable fact finding, information gathering, and communication with several of the
important constituencies which may be impacted, the Beach Taskforce recommends that the Mayor and
Council of the City of Tybee approve funding for an experimental dune stabilization and building
program which is very likely to lead to much more rapid dune stabilization and dune building. This
program will have significant community involvement and will have a viable monitoring apparatus in
place. Once approved, by the City of Tybee, application will be made to Georgia DNR to obtain a permit.
It is important that this program be implemented as soon as possible.
The project consists of three experimental sand fence configurations which will be constructed
and planted on the front beach. There will also be a designated area which will be planted without sand
fence configurations for the purpose of understanding the value of the proposed sand fence
configurations.
The project features rows of closed diamond shaped sand fence configurations that will be
planted and maintained. The diamonds will be approximately ten feet wide and the top point of each
diamond will point inland. Each of the four sides of the diamond will be ten feet in length. The sides of
the diamond will consist of sand fence which will be four feet high and anchored to treated posts at the
points of the diamond. There will be ten feet of open space between each diamond. The diamonds will
be three rows deep in staggered formation. The experimental sand fence configurations will be located
at three different footprints on the front beach away from the ocean and abutting and parallel to any
existing sand dune line. Currently there is no turtle activity at any of these sites.
Two locations will be approximately 280 feet in length parallel to the shore and 57 feet deep.
One site will be located on the beach just south of the North Beach Grill parking lot. The other similar
configuration will be located on the beach between 2nd and 3' Streets.
The third location will be approximately 140 feet in length and will be the same depth (57 feet)
as the first two described here. This location will be placed in the man-made gap in the primary dune
line immediately north of the 14th Street parking lot.
Closed diamond sand fence configurations will defend against damage caused by human traffic
to the flora planted inside of the diamonds. The diamonds containing flora should capture wind-blown
sand regardless of wind direction. The Diamonds will not capture nesting turtles.
It is important to the Beach Taskforce that the recommended dune stabilization/building
configurations be of little or no negative impact upon turtle and bird activity. The Taskforce has held
conversations with representatives of both turtle and bird interests in order to completely reveal the
experimental concept. No negatives caused by the project were identified, but some long term positives
were brought up. The Beach Taskforce will maintain communication with these two interests.
The South Carolina Department of Health and Environmental Control Office of Ocean and
Coastal Resource Management has excellent information on how and why to plant dunes. "One of the
most effective and aesthetically pleasing ways to build and stabilize a sand dune is to cover it with
vegetation". As per their recommendation, the Tybee project will be planted with three types of
herbaceous grasses that are suited to flourish on beaches of our coast. "The foliage helps increase the
size of the dune by trapping wind-blown sand. Plant roots also contribute as they bind sand particles to
the dune." Three species will be planted in the recommended planting methods and percentages. Each
species has slightly different growing characteristics and needs so we trust that some if not all three will
take hold.
Monitoring of the experimental project will be conducted by a qualified biologist and would be
conducted at least once per year on an annual basis following initial planting and created dune habitat.
Monitoring will include elevation surveys, the use of aerial photographs to map vegetation cover, the
use of a history or site sheet to record site characteristics and any management undertaken, use of
photo points to monitor change over time and simple methods for estimating vegetation cover by
species across the created dune habitat. Monitoring will be both quantitative and qualitative. The data
collected from monitoring will be used to inform management needs.
The Beach Taskforce recommends application for a State of Georgia Coastal Incentive Grant for
the funding of ongoing monitoring and maintenance of the initial project with additional funding of
project expansion hard costs as the project stabilizes and builds sand dunes.
To date, significant engineering services have been contributed to the project by Terracon
Engineering. Also, a "sustainable coast" one semester course at the University of Georgia is involved in
this project. We have requested that they produce an initial site analysis.
The following are the various costs which will be incurred:
Sand Fencing (firm price)
Treated Posts (firm price)
Plants delivered to Tybee (firm price)
Signage (firm price)
Monitoring first year (estimate)
Topographical Survey, initial and In yr.
Miscellaneous (fertilizer, etc.)
$4,874.88
2,240.00
3,978.35
948.21
2,000.00
(estimate) 2,400.00
1.000.00
$17,441.44
Respectfully Submitted,
Chair
Tybee Island Beach Management Taskforce