table 30 (Concluded) 



Date(s) Construction and Rehabilitation History 



1983- The outer 200 ft of the existing west jetty was in fair condition 

 1984 with an average elevation of +4.5 ft mlw, and the average water 

 (Cont) depth, seaward of the jetty, was -20 ft mlw. A scour valley ex- 

 tended along the toe of the west jetty head and was approximately 

 50 ft wide and 10 to 12 ft deep seaward of the jetty axis. The east 

 jetty wing extension was in fair condition with an average elevation 

 of +4.5 ft. The west jetty wing extension was in poor condition 

 with average elevations of +3.5, +0.5, and -7.5 ft mlw along succes- 

 sive landward sections of 700, 450, and 400 ft (landward end). Side 

 slopes were typically 1V:2H or less (i.e. 1V:3H). Rehabilitation of 

 1,060- and 1 ,240-f t-long seaward sections of the east and west 

 jetties, respectively, employed 3 design cross sections (Figure 51). 

 The inner trunk section had a +6 ft mlw crown elevation and 5- to 

 9-ton cover stone. The outer trunk section had a +7.5-ft mlw crown 

 elevation and 9- to 12-ton cover stone. Both sections had 15-ft 

 minimum crown widths. The head section had a +9 ft mlw crown eleva- 

 tion, 20-ft minimum crown width, and 12- to 20-ton cover stone. All 

 sections had 1-V:2-H side slopes except the head semicircles, which 

 were warped from IV: 2H (normal to the jetty axis) to 1V:3H (along 

 the jetty axis). Transition sections (both in geometry and stone 

 size) between the design sections were 100 ft long, except for the 

 east jetty inner to outer trunk transition, which was 79 ft long. 

 The lengths of the head, inner trunk, and outer trunk sections on 

 the east jetty were 100, 301, and 420 ft long, respectively, and on 

 the west jetty were 100, 300, and 500 ft long, respectively. The 

 estimated quantity of cover stone was 21,600 tons. The rehabilita- 

 tion also required removing approximately 150 ft of collapsed steel 

 sheet-pile wall on the west jetty (beginning 1,000 ft from the sea- 

 ward end) and breaking up the asphalt layer which covered sections 

 of both jetties (from the 1938 repairs), into segments no larger 

 than 20 sq ft. The entrance channel is presently maintained at a 

 depth of 42 ft and a width of 450 ft. Figure 52 is an aerial view 

 of the jetties taken prior to their rehabilitation. 



(Sheet 6 of 6) 

 92 



