INVESTIGATION OF DREDGED SEDIMENT MOVEMENT AND FATE AT THE 
ENTRANCE TO BRUNSWICK HARBOR, BRUNSWICK, GA 

The U.S. Army Corps of Engineers (Corps), Savannah 
District, routinely disposes of mixed dredged sediments in 
nearshore dredge disposal areas. Understanding the 
movement and fate of these sediments is critical to 
improved management of these sites. The Savannah 
District requested support from the U.S. Army Engineer 
Research and Development Center (ERDC) to perform 
field measurements and numerical modeling of the 
sediments placed in nearshore mounds. The Corps’ intent 
was to develop a dredged material disposal plan for an 
upcoming project. ERDC contracted Evans-Hamilton, Inc. 
(EHI), to conduct an extensive field measurement program 
at two nearshore disposal sites used for sediments from 
the Brunswick Harbor Entrance Channel. The data from 

Dredge Mound Bathymetry 


the measurement program would be used to evaluate and 
validate numerical models developed by ERDC to predict 
the fate and movement of dredged sediments placed in 
nearshore, open-water disposal areas. 

SCOPE AND APPROACH 

EHI, in coordination with ERDC and its subcontractor, 
Environmental Tracer Systems (ETS), developed a 
comprehensive 1-year data collection program for the 
project, which included monitoring of waves and currents at 
five locations, measurement of total suspended solids at 
three locations, high-resolution bathymetric surveys, 
dredge plume monitoring, and a sediment tracer study. 

The sediment tracer study was conducted using ETS’s 
proprietary sediment tracer techniques and involved 
deploying a silt and sand tracer at the two disposal sites, 
and monitoring the movement of the tracer over a 9-month 
period through a series of sediment sampling events. 

RESULTS 

The project produced a comprehensive data set of various 
physical parameters at the project site over approximately 
a 1-year period. The comprehensive nature of the data set 
has proven critical to providing a thorough understanding of 
the erosion and transport process occurring at the disposal 
sites. The tracer data showed that the fine-grained 
sediments eroded very rapidly and were transported over a 
large region within a matter of days. The sand tracer 
showed little movement, a result supported by the high-
resolution bathymetry that showed minimal loss of material 
from the mound region. The data set is being used by 
ERDC to refine and validate their numerical sediment 
transport models. 

Sediment Tracer Being Prepared for Deployment