Mississippi Coastal Improvements Program
Offshore Sand Search Investigation
Elizabeth S. Godsey, Mike S. FitzHarris, Justin S. McDonald, Jason B. Krick,
and Susan I. Rees, PhD.
Contact Information: U.S. Army Corps of Engineers, Mobile District, P.O. Box 2288, Mobile, AL
36628, USA, Phone: 251-690-2263, Email: Elizabeth.s.Godsey@usace.army.mil
The barrier islands fronting the Mississippi Sound have been losing surface area through time,
migrating rapidly to the west (except for Cat Island), and their capacity to protect mainland beaches
and infrastructure is diminishing (Byrnes et al. 2010). Rising sea level, severe storms, and
engineering activities (e.g. dredging of shipping channels) all threaten the sustained subaerial
presence (Twichell et al. 2011). Hurricane Katrina in 2005 severely impacted the mainland coast of
Mississippi and the barrier island system. Concerns over the likelihood of increased damage to
coastal communities shoreward of the islands during future storms resulted in the development of a
comprehensive improvement plan for the Mississippi coast. The 2009 Mississippi Coastal
Improvements Plan (MsCIP) Comprehensive Plan and Integrated Programmatic Environmental
Impact Statement (EIS) recognized that man‐made structures alone could not sufficiently reduce risk
for vulnerable areas along the coast. The MsCIP multi-agency team therefore integrated
nonstructural solutions such as voluntary buyouts in high risk areas and natural processes such as
marshes and barrier islands into a systems strategy for risk reduction.
The primary goal of the barrier island restoration component of MsCIP is to help restore sediment to
the system for natural transport as much possible along the islands given the realities of navigation
channel dredging, climate change and other anthropogenic activities. The majority of the Mississippi
Barrier islands: Petit Bois, Horn, East Ship, West Ship, and a portion of Cat comprise the Gulf
Islands National Seashore (GUIS), which is under the jurisdiction of the National Park Service
(NPS). Initial planning with the National Park Service (NPS) indicated that support of the project
could only be obtained if restoration was limited to an initial sediment placement to compensate for
anthropogenic activities with no additional maintenance of the placements thereafter to allow natural
coastal processes to shape the islands into the future. This is in keeping with NPS Director’s Order
12 that describes allowable activities that the NPS may perform within park boundaries.
The preliminary sediment budget completed as part of the 2009 MsCIP Comprehensive Plan and
Integrated Programmatic EIS documented that approximately 22 million cubic yards of sediment had
been dredged from and placed outside of the littoral system that feeds the Mississippi barrier islands.
The barrier island restoration component of MsCIP seeks to restore upto 22 million cubic yards of
compatible sediment within the littoral zone of the Mississippi portion of the GUIS including
Camille Cut and East Ship Island.
Since 2010 the U.S. Geological Survey (USGS), in collaboration with the U.S. Army Corps of
Engineers (USACE), have mapped much of the inner shelf offshore of the Mississippi barrier islands
in order to define the shallow stratigraphy of the region and assess the distribution and extent of
sediment deposits that could be mined for the large volume of material needed for the restoration.
Geophysical data collected by the USGS and vibracores collected by the USACE were integrated to
provide a detailed understanding of the regional shallow stratigraphy and the lithologies of its various
units. These efforts identified 19 potential sources of nearshore shelf sand offshore of the barrier
islands.
Bibliography: Elizabeth Godsey is Coastal Engineer Technical Lead at the U.S. Army Corp of
Engineers, Mobile District. Elizabeth Godsey has over 13 years of experience working on coastal
restoration, navigation and hurricane storm damage reduction projects having conducted and
overseen numerous engineering studies and designs of large scale civil works projects.