Hydrodynamic Influence and Morphological Evolution of Artificial Nearshore Berms along the
Florida Gulf Coasts
Katherine E. Brutsche1, Ping Wang1, Julie D. Rosati2, Tanya M. Beck2, Kelly R. Legault3
1: University of South Florida, Coastal Research Laboratory
4202 East Fowler Avenue SCA528, Tampa, FL, 33620; 813-974-3696
kebrutsche@usf.edu
2: U.S. Army Corps of Engineers, Coastal Hydraulics Laboratory, Vicksburg, MS
3: U.S. Army Corps of Engineers, Jacksonville District, Jacksonville, FL
Three artificial nearshore berms were constructed using maintenance dredged material of nearby inlets
along the west coast and Panhandle of Florida. The Fort Myers Beach berm (completed October 2009)
was placed in the form of a nearshore bar using material dredged from Matanzas Pass. At Perdido Key
(completed January 2012), the berm was placed in the swash zone using sediment from nearby Pensacola
Pass. The Egmont Key berm (completed May 2013) was constructed using material dredged from the
GIWW. Each study site represents a different nearshore placement design within a different wave
climate, thus offering an opportunity to compare the types of nearshore placements and their effects on
the hydrodynamics of the region, as well as the trends of morphological evolution.
At the Fort Myers Beach and Perdido Key sites, beach profiles were surveyed approximately bi-monthly
to semi-annually. Transects were surveyed within the berm project areas, as well as within two control
areas outside of the project areas. The Egmont Key berm was placed further offshore, requiring
hydrographic surveys to monitor the morphology changes. At the Egmont Key and Perdido Key sites
waves and currents were measured using PUV and ADCP sensors. At the Fort Myers Beach study site,
NOAA’s WAVEWATCHIII data was used to determine wave conditions during the study period.
Although demonstrated differently, both the Fort Myers Beach and Perdido Key berms moved onshore
through the duration of the study period. At Fort Myers Beach, the berm moved onshore much like a
natural bar would by eroding sediment from the seaward slope and depositing sediment in the landward
trough of the berm. Perdido Key, however, moved onshore in the form of overwash from winter storms
and two tropical systems, which was evidenced by the growth of a large storm berm. Some sediment also
moved offshore onto the natural bar, as well as alongshore into the control area west of the berm project
area.
The U.S. Army Corps of Engineers Coastal Modeling System (CMS) was used to investigate the
influence of the berm on nearshore wave and current fields at the three study sites. The measured
conditions were used to calibrate and verify the models. Results of the modeling efforts from this study
and future studies will be used for future guidance on nearshore placements along Florida’s Gulf coast.
The full presentation will include results of modeling efforts, as well as the morphological evolution of
the recently placed Egmont Key berm.
Katherine E. Brutsche Bio
Katherine Brutsche is a Ph.D. Candidate at the University of South Florida, where she also received her
Masters of Science degree in Geology in Summer 2011. Her Bachelor of Science degree in Geosciences,
with dual emphasis in Geology and Earth Science Education, was completed at Virginia Tech. Her thesis
research focused on the sediment characteristics and morphological impacts of the nearshore placement of
dredged material in Fort Myers Beach, Florida. Her dissertation research is a continuation of her studies
at Fort Myers Beach, and includes two more nearshore berm study sites at Perdido Key and Egmont Key.
She has also been involved with many other research projects within the Coastal Research Lab at USF.