Table 15 



St. Augustine Harbor North Groin and South Jetty 



St. Augustine Harbor, Florida, SAJ 



Date(s) Construction and Rehabilitation History 



1941 During 1941 a sand-tight terminal groin of timber wall, native 

 stone, and granite was constructed to a length of 1,580 ft, and 



450 lin ft of cresote-treated timber was placed at its shoreward end 

 (Figure 26). The groin (Figure 27) side slopes were 1V:1.5H. Crown 

 widths varied from 6 to 12 ft, and the crown elevation varied from 

 +10 to +6 ft mlw at the shoreward and seaward ends, respectively. A 

 2-ft-thick mat foundation was placed using 8,000 tons of native 

 stone, and 13,300 tons of mostly 5- to 10-ton stone was used to com- 

 plete the groin. (The largest stone was to be placed at the seaward 

 end.) The cost of the structure was $305,000. 



1942 Granite stone, weighing 600 tons, was placed on the south side of 

 the north groin at an exposed section of core wall. This placement 

 was necessary since sand had been accreting on the north side and 

 eroding on the south side to the point that the highwater line was 

 150 ft west of the structure. Cost of the repair was $4,200. 



1943 Repairs were made to 350 ft of the existing north groin, and a 

 300-ft shoreward extension was completed using 20- to 100-lb core 

 stone and 300- to 1,000-lb cap stone to guard against flanking of 

 the structure by the continued recession of the shoreline south of 

 the groin. The repairs cost $54,600. 



1949 The seaward 100 ft of north groin had gradually subsided below mhw 

 (+4.5 ft). 



1956- A 2,825-ft-long sand-tight south jetty was constructed (Figure 28) 

 1957 approximately 2,400 ft south of the existing north groin, providing 

 protection for a 16-ft-deep channel. The sand-tight section (land- 

 ward 1,800 ft) was constructed to +10 ft mlw with a 10-ft crown 

 width and 1V:1.5H side slopes. The cover stone was 2 to 8 tons with 

 a core of 200-lb maximum stone placed on a 2.5-ft-thick foundation 

 blanket (the entire length of the jetty) of 1- to 12-in. pieces. 

 Seaward of this section the crown width was 12 ft, the crest eleva- 

 tion was +6 ft (via 300-ft transition) , and the side slopes were 

 1V:1.5H. The core stone was 200 to 4,000 lb, and the cover stone 

 consisted to 6- to 10-ton stone. The outeinnost 350 ft of the struc- 

 ture had side slopes of IV: 2H and used 10-ton minimum cover stone. 

 The channel side of the jetty was protected by a 3-ft-thick apron, 

 40 ft wide consisting of a 1-ft-thick filter bed of 1- to 12-in. 

 stone, overlayed with 75- to 1,500-lb riprap stone. The total cost 

 of the jetty plus a shoreward revetment section was $967,000. 



(Continued) 

 49 



