Table 30 (Continued) 



Date(s) Construction and Rehabilitation History 



1966 land side. The berms were identical in design to the 1963 berm. 



(Cont) The cover stone was placed to +6 ft mlw, a 15-ft minimum crown 



width, and 1V:1.5H side slopes. A total of 13,160 tons of stone was 

 placed at a cost of $145,700. The repairs were required to prevent 

 further deterioration of the structure and eliminate the need for 

 more costly repairs in the future. The erosion at the toe of the 

 jetty had been most severe on the channel side, and the resulting 

 settlement had caused a split in the jetty along the sheet-pile core 

 wall. The combination of settlement and wave attack had lowered 

 sections on the channel side to below mlw. The outer 100 ft of the 

 jetty was seriously deteriorated with top elevations from +3 ft mlw 

 to below mlw. The next 200 ft at the seaward end had considerable 

 displacement of cover stone and exposed portions of core stone. The 

 outer 100 ft of the jetty was not repaired because (a) it would be 

 expensive to repair, and (b) it would act as a berm and prevent 

 undermining of the repaired outer end. The design wave height of 

 21 ft was based on a +6 ft mlw surge level, a water depth of 21 ft, 

 and depth-limiting conditions. Although several methods were used 

 to compute cover stone size, these were used as a rough guide; and 

 the size was determined from a number of practical considerations. 



1968 The west jetty extension was rehabilitated during the summer at a 

 cost of $29,100 (no details available). 



1973 The 2,025-f t-long east jetty, rehabilitated with cover stone and 

 berm stone (toe apron), was placed along portions of the channel 

 side. In many respects, this work was similar to the 1966 west 

 jetty repairs. On the inner 1,525 ft 6- to 8-ton cover stone was 

 placed, and on the seaward 500 ft 8- to 12-ton cover was placed. 

 The design section called for a crest elevation of +6 ft mlw, crest 

 widths of 9 and 15 ft on the landward and seaward sections, respec- 

 tively, and 1-V:1.5-H side slopes. Berm stone was placed along the 

 inner 950 ft and placed in a semicircle around the jetty head. Berm 

 stone was also placed on two sections, one section extending 100 ft 

 seaward from the jetty hook and the other section 50 ft long, start- 

 ing 100 ft landward of the jetty hook. The berm design section was 

 similar to the 1966 berm except for a specified thickness of 3 to 

 5 ft. The cost of repairs was $172,200. 



1983- The jetties were surveyed during the summer of 1983 to determine 

 1984 existing conditions prior to their rehabilitation in 1984. The 



trunk sections of both jetties were in good condition with average 

 centerline elevations of +6 ft mlw. The outer 150 ft of the east 

 jetty was in poor condition with an average elevation of +2 ft mlw, 

 and the average water depth, seaward of the jetty, was -15 ft mlw. 



(Continued) 



(Sheet 5 of 6) 



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