2 Functional Design Guidance 



Functional Design Objectives 



Prototype experience shows that detached breakwaters can be an important 

 alternative for shoreline stabilization in the United States. Shoreline 

 stabilization structures such as breakwaters or groins seek to retain or create a 

 beach area through accretion, as opposed to structures such as seawalls or 

 revetments, which are designed to armor and maintain the shoreline at a 

 specific location. Additionally, breakwaters can provide protection to a 

 project area while allowing longshore transport to move through the area to 

 downdrift beaches. 



The primary objectives of a breakwater system are to increase the 

 longevity of a beach fill, provide a wide beach for recreation, and provide 

 protection to upland areas from waves and flooding (EM 1110-2-1617). 

 Breakwaters can also be used with the objective of creating or stabilizing 

 wetland areas. The breakwater design should seek to minimize negative 

 impacts of the structure on downdrift shorelines. 



Beach nourishment has become an increasingly popular method of coastal 

 protection. However, for economic and public perception reasons, it is 

 desirable to increase the time interval between renourishments, that is, to 

 lengthen the amount of time that the fill material remains on the beach. This 

 increase in fill longevity can be accomplished through the use of shoreline 

 stabilization structures, such as a detached breakwater system. The 

 combination of beach nourishment and structures can provide a successful 

 means of creating and maintaining a wide protective and recreational beach. 

 Lakeview Park, Ohio, is an example of a recreational beach maintained by a 

 combination of breakwaters, groins, and beach fill (Bender 1992) (Figure 8). 



12 



Chapter 2 Functional Design Guidance 



