PART III: RESULTS 

 Profile Changes 



37. Profiles of the beach showing project performance from its comple- 

 tion in 1982 through May 1984 are presented in Figures 8 and 9. A summary of 

 estimated volume changes derived from these profiles is given in Table 4. 

 Between the as-built (1982) survey and June 1983 survey (approximately 1 year 

 of project operation), most of the profile changes occurred in an offshore 

 direction as material in the construction berm moved downslope as expected. 

 For example, between baseline sta 0+00 and 100+00, the volume of material 

 above the -4 ft elevation decreased by 424,500 cu yd while between the -4 ft 

 and -25 ft depths, the volume of material increased by 394,800 cu yd yield- 

 ing a net loss for the entire 10,000-ft segment of only 29,700 cu yd. From 

 sta 100+00 to 140+00, a similar adjustment occurred with 366,600 cu yd being 

 removed from above the -4 ft level and 331,600 cu yd accumulating between 



-4 ft and -25 ft resulting in a net loss of 35,000 cu yd from the northern 

 4,000 ft of the project. Overall, the net loss of material from the project 

 during the first year was 64,700 cu yd, considerably below the estimated 

 deficit of 160,000 cu yd/year predicted by the feasibility report (O'Brien 

 1931 )*. By the end of the first year, however, practically all of the 

 material placed above -4 ft in front of the seawall from sta 120+00 north 

 had been removed. North of the project limits, between sta 140+00 and 180+00, 

 there was a net buildup of material between August 1982 and June 1983 of 

 217,000 cu yd. 



38. From June 1983 to May 1984 (second year of project operation), 

 losses from the project fill above the -4 ft level increased considerably, 

 with the southern 10,000-ft section losing 64,900 cu yd and the northern 

 4,000-ft section losing 94,800 cu yd. Unlike the first year, sediment 

 losses also occurred below the -4 ft depth. Over the southern 10,000 ft of 

 the project, losses below -4 ft amounted to 131,900 cu yd, while between 

 sta 100+00 and 140+00, the lower portion of the profile lost 248,100 cu yd. 

 In all, the southern 10,000 ft of the project lost 196,800 cu yd during 

 the second year of project operation, and the northern 4,000 ft lost 



* Op cit. 



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