ERDC/CHL CHETN-II-47
March 2004
Figure 16. Hot spot location and nodal point at Tybee Island, GA, fill project (courtesy of Carol
Abercrombie, Savannah District)
Dade County, FL. The Dade County Shore Protection Project has undergone several construction
phases and covers almost the entire county. Sand has been placed on the beach at various times from
Sunny Isles in the north to Key Biscayne in the south. The beach nourishment project has developed
five hot spots (Figure 17). The first hot spot is located at Sunny Isles and results from end losses at
the northern project limit taper. A second hot spot is located downdrift (south) of Bakers Haulover
Inlet at Bal Harbor. This hot spot results from downdrift inlet effects from the two navigation jetties.
The third hot spot is located in the vicinity of 63rd Street in Miami Beach and is suspected to result
from wave energy focusing over nearshore hardbottom reefs. The fourth hot spot is located at 32nd
Street, Miami Beach and is the result of an orientation change in the shoreline. The fifth hot spot is
located at the southern terminus of the project at Government Cut and is suspected to be the result of
sand leakage through the porous north jetty.
Mitigation of the Dade County hot spots involves a variety of approaches (Figure 18). The Sunny
Isles end effect hot spot was mitigated by construction of two submerged rubble-mound breakwaters
in 2001. These breakwaters were designed to lower the wave energy as it approached the beach and
reduce end losses to the north. The breakwaters have performed well and are holding the fill material
in place. No mitigative action has been taken at the south jetty of Bakers Haulover Inlet at this time.
The hot spot at 63rd Street will become part of the National Shoreline Erosion Control Development
and Demonstration Program (Section 227) project to construct and test innovative shore protection
19
Previous Page
