In the first 2 years after the initial placement of 749,300 cubic meters 

 (980,000 cubic yards) of fill along the 1200-meter northern section of the 

 project, beach changes were greater than those in the longer, southern sec- 

 tion. Although about 420,500 cubic meters (550,000 cubic yards) of fill was 

 lost from the active profile, amounting to a 56-percent reduction in the total 

 inplace fill, this only exceeded the anticipated winnowing loss by about 9 

 percent. By March 1967, the HWL along this section receded 43 meters (140 

 feet), resulting in the complete loss of 460 linear meters (1,500 linear feet) 

 of original fill and the severe loss of an additional 360 meters (1,200 

 feet) of fill. This erosion progressed rapidly in a southward direction and 

 threatened the more stable southern section of the project. 



In March 1967, emergency measures were taken. The north end of Carolina 

 Beach was restored by placing about 275,000 cubic meters (360,000 cubic yards) 

 of fill and by building a 123-meter (405 foot) groin near the north end. The 

 groin was necessary because there was a reversal in the predominant direction 

 of the longshore transport at the north end. In the next year, approximately 

 155,200 cubic meters (203,000 cubic yards) of emergency fill eroded, and most 

 of the shoreline returned to about normal configuration before the emergency 

 work. The shoreline immediately south of the groin, for a distance of about 

 120 meters (400 feet), remained nearly stable, and the loss of emergency fill 

 along this small segment was about 42 percent less than the loss along the 

 remaining emergency section. 



Survey records from 1938 to 1957 (reported in the original project 

 report) show that the average annual recession rate was about 0.3 meter (1 

 foot) per year, with a short-term maximum rate of 0.9 meter (2.8 feet) from 

 1952 to 1957, when the area had been exposed to four major hurricanes. The 

 annual loss of material for the entire active profile was estimated to be 

 about 10 cubic meters per linear meter (4 cubic yards per linear foot). 



During the 2 years following the fill, the effects of shore processes 

 were radically different from processes determined from historical records. 

 During the periods April 1965 to April 1966 and April 1966 to April 1967 , the 

 shoreline receded 20 and 5 meters (67 and 15 feet), respectively, with 

 corresponding losses of 283,000 and 261,500 cubic meters (370,000 and 342,000 

 cubic yards). In the third year, April 1967 to April 1968, a marked change 

 occurred in fill response. The rate of shoreline recession dropped to 1.5 

 meters (5 feet) per year, and the volume change of material amounted to a 

 slight accretion of about 13,000 cubic meters (17,000 cubic yards). Surveys 

 in 1969 indicated that the project was in nearly the same condition as it was 

 in 1968. 



Rapid recession of the Carolina Beach shoreline during the first 2 years 

 was a result of the profile adjustment along the active profile which termi- 

 nates at depths between -7 and -9 meters (-22 and -30 feet) MLW, as well as 

 net losses in volume resulting from the natural sorting action displacing the 

 fine material to depths seaward of the active profile. The foreshore and 

 nearshore design profile slope of 1 on 20 was terminated at a depth of 1.2 

 meters (4 feet) below MLW. The adjusted project profile of April 1968 shows 

 the actual profile closing at a depth of about 7 meters below MLW, with a 

 characteristic bar and trough system. Thus, displacement of the initial fill 

 with the accompanying reduction of the beach design section resulted from a 



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