Louisiana Surficial Sediment Distribution Mapping
Melany Larenas, PG.1, Syed Khalil,2, Beth Forrest, PhD1, Kristina Dennis, MSc.1 and Tara
Devine1
1. Coastal Planning & Engineering, Inc./A Shaw Group Company., 2481 NW Boca Raton Blvd.,
Boca Raton FL 33431
2. Coastal Protection and Restoration Authority of Louisiana (CPRA), 450 Laurel Street, Suite
1500, P.O. Box 44027, Baton Rouge, LA 70804
The Louisiana coastline is experiencing some of the most extreme erosion rates in the country.
Consequently, major coastal infrastructure and marsh habitats are being seriously threatened.
The 2012 Master Plan for the state of Louisiana is a major initiative that addresses concerns
related to the future of Louisiana’s coast. This program is guided by a Master Plan Delivery
Team, which is made up of members of the Coastal Protection and Restoration Authority of
Louisiana (CPRA) as well as the office’s contractors and an embedded team from the U.S. Army
Corps of Engineers (USACE). This team is supported by over fifty (50) advisors, independent
reviewers and modelers. The Master Plan Delivery Team has been assembling the technical tools
and data required to support sound decision making. To assist in planning coastal restoration
projects for the 2012 Master Plan, preliminary surficial sediment distribution maps for Offshore
Coastal Louisiana and the Lower Mississippi River were developed.
One of the major causes of shoreline retreat in Louisiana is sediment deficiency. Restoration
efforts must therefore focus on the introduction of new sediments to the system. Marine sand
mining on the US continental shelf is a major activity that supplies sediment for restoration
activities. However, the muddy coasts of the Mississippi Delta region are problematic because
sand resources are scarce and their quality is variable. The potential for riverine mining of sand
resources to support construction of future coastal restoration projects provides a possible
solution to this problem. To assess the distribution of sediments both offshore and within the
Lower Mississippi River, existing geophysical and geotechnical data were examined. This
information was used to develop sediment distribution maps and based on these maps potential
sediment volumes were approximated.
Twenty (20) sediment resources were identified along the lower Mississippi River and twentynine (29) sediment resources were identified offshore Louisiana. These resources were classified
as surficial sand, surficial mixed sediment and surficial fines. Areas where no data were
available were labeled “unknown”. This information was used to create two (2) overview maps
and four (4) map series which show various data layers. The surficial sediment boundaries that
were delimited during this project will be used by the State of Louisiana to facilitate regional
sediment management. These boundaries will also be modified as new data is collected and
reviewed by the State.