were not made, a considerable portion of the material eroded from the fore- 

 shore by Diana was probably displaced seaward to form shore-parallel bars. 

 With the passage of the storm and a return to milder wave conditions, some of 

 this displaced material is expected to work its way back onto the foreshore. 

 Evidence of this poststorm recovery phenomenon was observed from repeat sur- 

 veys made of profile sta 90+00, 100+00, and 110+00 on 4 October 1984, an exam- 

 ple of which is shown for sta 100+00 in Figure 13. At these three profile 

 stations, the foreshore had moved seaward between 5 and 15 ft during the 

 26 September to 4 October period. 



54. Foreshore erosion associated with Hurricane Diana along the north- 

 ern 4,000 ft of the Carolina Beach project was limited since most of the 1982 

 fill material placed in front of the seawall had been eroded prior to the 

 storm. Between May 1984 and September 1984, the amount of material removed 

 from the foreshore between sta 100+00 and 140+00 was 49,600 cu yd. Of this 

 amount, 32,600 cu yd was removed from the berm and dune section between 



sta 100+00 and 116+40, and 17,000 cu yd was lost from in front of the seawall. 

 Based on the average rate of foreshore erosion that occurred between June 1983 

 and May 1984 along this 4,000-ft segment, normal or nonstorm-related erosion 

 would have displaced about 38,000 cu yd. Therefore, only 11,600 cu yd of 

 foreshore erosion can be attributed to Hurricane Diana in this 4,000-ft reach. 

 Poststorm recovery of the beach profile immediately south of the seawall did 

 not occur, as evidenced by a 4 October 1984 survey of sta 115+00 which indi- 

 cated additional erosion since the September poststorm survey. 



Carolina Beach Inlet Sediment Trap 



55. Surveys of the sediment trap in Carolina Beach Inlet, created with 

 the removal of 406,000 cu yd of material during the May 1981 emergency beach 

 nourishment operation, showed an accumulation of 270,000 cu yd of sand as of 

 May 1984. This represents an annual accumulation rate of 90,000 cu yd/year. 



56. The rate of accumulation during the 36-month period was not con- 

 stant as shown by the incremental filling rates given in Table 6. During the 

 initial 7-month period from May 1981 to September 1981, the average rate of 

 sediment accumulation was 13,700 cu yd/month, while over the next 29-month 

 period, the rate decreased and remained fairly constant, averaging about 

 6,000 cu yd/month. A scour, and fill map of the deposition basin, which covers 



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