Analyses were performed to include Masonboro, Kure, and Fort Fisher 

 Beaches into one continuous sediment budget analysis; however, the lack 

 of reliable long-term volumetric change data along those beaches meant 

 that large and somewhat arbitrary changes in either the volumetric 

 excursion rates, energy flux values, or /3 values were needed to balance 

 all sediment budget equations. Because of these changes, the results 

 were not meaningful and are not presented. 



VI. BEACH-FILL PERFORMANCE 



All beach fills placed along the study area between 1965 and 1975 

 were discussed in Section II; Table 4 and Figure 8 of Section IV show 

 additional detailed information on their location and time of placement. 

 The beach fills are also discussed in Vallianos (1970), U.S. Army 

 Engineer District, Wilmington (1970, 1974, 1977), and Jarrett (1977). 

 Information presented in this section is based on the quantitative 

 interpretation of the excursion distance analyses of the 1970 beach fill 

 on Wrightsville Beach and of the 1965 and 1971 beach fills on Carolina 

 Beach. There was insufficient repetitive profile information for the 

 other fills to allow excursion analysis and subsequent fill performance 

 evaluation. 



The 1970 beach fill along the central part of Wrightsville Beach was 

 the best documented (in terms of repetitive beach surveys before and 

 after placement of fill material) beach-fill project, and the excursion 

 distance plots of profiles WB13 to WB29 (App. A) show the response of 

 the beach to this fill. Sequential profiles showing the post-fill 

 behavior at profile WB-15 are presented in Appendix F. All relevant 

 data from all of these plots are summarized in Figure 43 which shows the 

 spatial variation along the beach of the initial fill excursion, the 

 percent total initial losses, the net excursion after initial losses, 

 the long-term erosion rate, and the value of the exponential decay 

 constant, k. All values in the figure are averaged from the MLW, MSL, 

 and MHW excursion distance plot of each profile located along the 

 central section of Wrightsville Beach. 



The average initial fill excursion, as defined by the first measure- 

 ments taken after fill placement, was 76.6 meters, and the distribution 

 of the fill along the beach was almost triangular. The maximum initial 

 excursion was approximately 125 meters in the middle and the excursion 

 at the project boundaries was approximately 50 meters. Figure 43 shows 

 that beach excursions were measurable along the beaches on either side 

 of the project boundaries soon after the initial fill placement. These 

 edge excursions indicate that some of the material placed within the 

 project limits of the fill quickly spread laterally to the adjacent 

 beaches. The average fill excursion remaining on the beach face, after 

 all initial losses had occurred (approximately 2 years), was 15.5 meters 

 with a maximum retention of 29 meters in the middle of the fill. This 

 means that 80 percent of the initial fill was lost due to sorting, slope 

 readjustment, and lateral spreading. The southern end of the fill 

 experienced the highest initial loss of 90 percent where only 5 meters 

 of excursion remained after approximately 1.5 years. 



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