Fig. 8. Aerial photograph of the Holly Beach breakwaters (March 1986) 



mounted on one row of timber piles) having the greatest transmission. During 

 typical wave conditions, the riprap unit to the west showed no transmission, 

 but, because of its low crest height, it was observed to be overtopped during 

 storms . 



The west (riprap) breakwater was placed 78 m offshore and the other five 

 breakwater approximately 62 m offshore. The breakwaters are nominally 50 m 

 long with a gap width of approximately 90 m and have effective crest heights 

 ranging from 1.2 to 1.8 m above MSL. Within a few months after construction, 

 large salients had formed behind the three western structures of lower wave 

 transmission. These shoreline forms showed considerable movement and deforma- 

 tion with passage of Hurricane Bonnie on 26 June 1986. All salients remained 

 intact but shifted 50 m to the east and decreased in their seaward extent by 

 30 to 70 percent. The eastern-most breakwater constructed of a single row of 

 timbers incurred major damage during Hurricane Bonnie, but regeneration of a 

 small salient subsequent to the storm nevertheless occurred. 



53 



