Fact Sheet
US Army Corps of Engineers
U.S. Army Engineer Research and Development Center
July 2003
Public Affairs Office
3909 Halls Ferry Road Vicksburg, MS 39180-6199 (601) 634-2504
CHL web site chl.erdc.usace.army.mil
Monitoring Study of Aguadilla Harbor, Puerto Rico
Purpose: To describe monitoring activates being conducted at Aguadilla Harbor, Aguadilla, Puerto Rico, as part of
the Corps of Engineers' Monitoring Completed Navigation Projects (MCNP) Program.
Background: Since its construction in 1995,
the Aguadilla small boat harbor, located on the
northwest coast of Puerto Rico, has suffered
from shoaling by littoral sediment moving
through the more porous sections of the
breakwater and around the southern tip of the
structure. In essence the harbor is trapping
sediment during storm events. The City of
Aguadilla does not have the resources
necessary to keep the harbor free of sediment
through regular dredging. In 2001 the Coastal
and Hydraulics Laboratory began a four-year
monitoring program to assess the performance
and functionality of the harbor and breakwater
project relative to its design goals.
Facts: The original monitoring plan included components to examine sand transport through the porous breakwater
into the harbor, but throughout the time period of monitoring, the harbor has been substantially shoaled making this
task unfeasible. The four remaining monitoring tasks are the following: (1) investigate the physical mechanisms that
result in harbor shoaling; (2) determine the local sediment pathways that are active during storms; (3) confirm the
structural stability of the breakwater; and (4) assess whether southward moving littoral sediment continues to be
impounded by the breakwater. The monitoring plan includes several activities that contribute to one or more of the
above monitoring tasks. Aerial shoreline photography was obtained simultaneously with detailed bathymetry
acquired by the SHOALS airborne lidar bathymeter. Directional wave data were acquired offshore of the breakwater
by a bottom-mounted, internally-recording wave gauge. A geophysical survey of the region offshore of the harbor
provided maps showing composition of the bottom (rock or sand) and depth of sand deposits. Over 250 sand samples
collected over a grid offshore of the breakwater were used to develop likely sediment pathways based on the
Sediment Trend Analysis technique. The abundance of beach-sized sand observed offshore, combined with
projected sediment pathways indicates that much of the sand shoaling the harbor comes from offshore. Previously
acquired beach profiles were analyzed along with profiles acquired during the monitoring to assess changes that have
occurred north of the breakwater. Finally, breakwater structural integrity was assessed using traditional survey
techniques augmented by diver visual inspection of the seaward breakwater toe. Monitoring will conclude in 2004
with production of the final monitoring report.
Points of Contact: For additional information, please contact
Dr. Steven Hughes at 601-634-2026 ( ), or
Mr. Dennis Markle at 601-634-3460 ( )"> ).
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