the 3-year period from May 1981 to May 1984, is given in Figure 14. Of the 

 270,000 cu yd total accumulation, 223,000 cu yd, or 77 percent, deposited in 

 the seawardmost portion of the trap, which is designated as "Fill Area No. 1" 

 in Figure 14. The middle portion of the trap, accumulated 65,500 cu yd of new 

 sand in "Fill Area No. 2" but also lost 15,500 cu yd to natural scour result- 

 ing in a net accumulation of 50,000 cu yd. The landward end of the trap, 

 which extends about 500 ft seaward of the AIWW, gained 17,800 cu yd of new 

 material. However, the adjacent areas north and south of this section of the 

 trap lost a combined total of 20,800 cu yd to scour, yielding a net loss of 

 3,000 cu yd of sediment from the entire landwardmost area. Failure of the 

 middle and landward ends of the trap to retain substantial quantities of sedi- 

 ment was due to the concentration of tidal flow through these areas which, in 

 essence, presently constitute the inlet gorge. Overall, the trap has func- 

 tioned well, but the average annual accumulation of 90,000 cu yd is below that 

 needed to keep pace with the erosion losses from the Carolina Beach project. 



57. Since the seaward portion of the sediment trap was rather efficient 

 in trapping material whereas the middle and landward portions were not, the 

 sediment trap was repositioned seaward during the 1985 renourishment of Caro- 

 lina Beach. The new location, shown in Figure 4, was outside the area of con- 

 centrated tidal currents that prevented material from depositing in the orig- 

 inal trap. 



Tidal Current Measurement 



58. A summary of the tidal current measurements made in Carolina Beach 

 Inlet is given in Table 7. These measurements were made in the sediment trap 

 area along a range located approximately 700 ft seaward of the AIWW. These 

 current and discharge measurements indicate that the total volume of water 

 flowing through Carolina Beach Inlet, the tidal prism, did not change as a re- 

 sult of the dredging of the sediment trap; however, discharge velocities did 

 decrease. Discharge velocities have remained rather low in this section of 

 the trap due to its failure to accumulate any substantial quantities of 

 material. 



59. Based on a September 1981 hydrographic survey, the minimum cross- 

 sectional flow area in Carolina Beach, which was measured seaward of the 

 dredged sediment trap, was 7,050 sq ft. The relationship between an inlet's 



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