The Army Corp of Engineer's Vicksburg Modeling Center

The Army Corp of Engineer's Vicksburg Modeling Center did extensive modeling on Reef Balls for use as submerged breakwaters. A design has been selected using Reef Ball™ units as an offshore reef breakwater. Reef Balls? are hollow concrete hemispheres designed for marine habitat enhancement. Placed in parallel rows as an offshore breakwater, Reef Balls? will reduce the wave energy reaching the beach both by physically blocking the incident waves and by generating turbulence through the interstices in and around the concrete units. Reef Balls? are usually fastened to a hard substrate with fiberglass reinforcing bars. However, the Miami site has a sandy substrate. To provide stability and prevent the units from sinking into the sand, the Reef Balls? will be mounted on concrete articulated mattresses placed on a bedding layer. The purpose of the breakwater is to reduce wave energy reaching the beach, thereby reducing the movement of the sand, extending the time between renourishments, and increasing the storm protection to adjacent buildings. Additional benefits of the Reef Ball? design include improved habitat for marine life, and as the Reef Balls? become covered with marine growth, the design will provide recreational benefits as a snorkeling trail. The primary objective of the demonstration project is to hold the maintain template dimensions between renourishment in an innovative or nontraditional manner. This demonstration project will also document the performance other nontraditional methods implemented maintain the beach nourishment design template at other erosional hot spots in the BEC&HP (e.g., use submerged rubble-mound reef for wave attenuation, and use of T-head groins or headland structures for sediment retention).