EM 1110-2-1100 (Part V)
31 Jul 2003
Figure V-4-3. Use of groin structures to enhance beach nourishment projects
What is the extent of the littoral cell, and where within the cell will the project reside? What are the important
coastal processes that characterize the littoral cell and the project site? The answers to these questions will
influence how a project is designed, how it performs, and what if any impacts it may have on adjacent
beaches.
(1) Site location within littoral cell. The location of the project within a littoral cell has great influence
on all aspects of a beach nourishment project, from understanding the underlying coastal processes at work,
to determining the design concept that might be most effective, to the choice of methods and tools used in
the design process. For example, will the project be constructed well within the interior of a littoral cell, miles
from the inlets that serve as boundaries of the cell, or will it be built immediately downdrift of an inlet
stabilization structure, or along the throat of an unstructured inlet? Sand transport by tidal currents, wave
refraction over complex bathymetry, and wave-current interaction may not be important design issues in the
former case whereas these processes may be critical in designing an effective project in the latter. In the
former case, the project may experience beach recovery following a storm, where much of the sand moved
offshore into a storm bar, migrates back onto the shore face with little net loss of sand. In the latter case, sand
V-4-6
Beach Fill Design
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