Table 20 (Continued) 



Date(s) Construction and Rehabilitation History 



1945 was one reason for the 1934-38 rehabilitation. Examination of the 

 (Cont) jetty heads showed that the north jetty, with its asphaltic con- 

 crete, was in good condition but that the south jetty, without the 

 asphaltic concrete, had deteriorated and needed 1,000 to 1,500 tons 

 of 8- to 10-ton stone to restore the original design. 



1948- The south jetty was inspected and surveyed. The outer 500 ft of the 



1949 cap had settled 1 to 6 in. because of displacement of the underlying 

 armor stone (occurred during the hurricane of 11-19 September 1947). 

 On the landward half of the cap were a number of holes resulting 

 from serious loss of armor stone from wave action. Near the shore- 

 ward end of the cap, a 40-ft section was cracked badly. By this 

 time, the nonasphalted head of the jetty had largely disappeared. 

 There was also some deterioration along a 170-ft section at the 

 jetty cap revetment interface. Undermining of stone because of wave 

 action and currents (scouring) was felt to be the major cause of 

 deterioration. The channel was deepened to -27 ft mlw. 



1950 In January 1950 repairs to the north jetty consisted of (a) placing 

 a filter blanket of 1/4- to 6-in. stone along 200 ft of its shore- 

 side landward junction (to impede sand motion) and (b) placing 

 existing and additional 500- to 2,000-lb armor stone at the 

 revetment/ jetty cap interface (30-ft section). 



In March 1950 repair of the south jetty consisted of placing 2- to 

 10-ton armor stone as needed. Total cost of the repairs to the 

 south jetty (26,000 tons of stone placed) and revetment was 

 $227,000. (The jetty portion was roughly 90 percent of the total.) 



In August 1950 an underwater survey of the asphalt-filled north 

 jetty showed some deterioration on the channel side; otherwise, it 

 continued to function properly. 



1955 Repairs were made to the north jetty from the existing shoreline to 

 the landward end of the concrete cap (500 ft) . A total of 

 1,300 tons of 6-ton minimum capstone was placed on the channel side 

 of the repair section. Filter layers were placed on the shoreward 

 side of the cap as follows (Figure 34) : (a) 2-f t-thick lower layer 

 of 3- to 6-in. stone placed above, and shoreward of, new/existing 

 armor stone, (b) overlayed with 9 in. of 0.1- to 0.4-in. material, 

 and (c) covered by a layer of 500- to 4,000-lb riprap stone. Total 

 cost of the repairs was $51,000. 



1958 The sand transfer plant began operation. The plant was built to 

 maintain the net southerly littoral drift in addition to beach 

 renourishment from dredging. 



(Continued) 



(Sheet 2 of 3) 



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