Table 8 (Continued) 



Date(s) Construction and Rehabilitation History 



i960 the east Jetty, and from 0- to +5 ft mlg on the groin. Soil subsi- 

 (cont.) dence was considered to be the major cause of Jetty deterioration. 

 Seaward sections of the east and west Jetties, 700 and 800 ft long, 

 respectively, were brought up to +6 ft mlg with a 6-ft top width and 

 1V:1.5H side slopes. The 345-ft-long groin was repaired to an eleva- 

 tion of +5 ft mlg, a 5-ft top width, and 1V:1.5H side slopes. Stone 

 size was determined from Hudson's formula for a 9-ft depth-limited 

 wave height. (The design called for the larger stones to be placed 

 on the outermost surface.) The $56,000 cost of repairs included 

 sweeping (removing exposed rock, piles, etc.) a 150-ft-wide section 

 along the channel side of the west Jetty and placing about 4,000 tons 

 of stone. 



1964 Repairs were made to the groin and sections of the east Jetty. The 

 landward ends were extended, making the east Jetty and groin 1,250 

 and 630 ft long, respectively. These extensions were needed due to 

 continued recession of the shoreline, which resulted in flanking of 

 both structures. The groin was brought up to +5 ft mlg with a 6-ft 

 top width and 1V:1.5H side slopes, using 1- to 6-ton stone on the 

 seaward section and 200- to 2,000-lb stone on the 250-ft landward 

 extension. (A 1-ft-thick bedding layer was placed also.) The east 

 Jetty sections were brought up to +6 ft with 1V:1.5H side slopes 

 using 1- to 6-ton stone. The top widths were 6 ft on the 275-ft 

 landward (including extension) and 125-ft middle sections, and 10 ft 

 on the 200-ft seaward end section. Prior to repairs, the center-line 

 elevations (September 1963' survey) were from -2 to +3.5 ft mlg on the 

 groin, from +3 to +7 ft mlg on the east Jetty, and from +5 to +9 ft 

 on the west Jetty. The total cost of placing 8,240 tons of stone and 

 600 lin ft of sand fence was $48,900. 



1966 Repairs were made to the groin and east Jetty, their landward ends 



were extended 100 and 135 ft, respectively, and a 290-ft-long rubble- 

 mound dike was constructed along the shoreline, connecting the two 

 structures. The existing center-line elevations (December 1965 

 survey) were from +1 to +5 ft mlg on the groin and from +1 to +7 ft 

 mlg on the east Jetty. The design geometries were identical to those 

 used in 1964. A 1-ft-thick blanket of shell was placed along 200-ft 

 sections at the landward ends of the structures and along the dike. 

 These sections were completed using 500- to 4,000-lb stone, and the 

 remaining repairs used 1- to 6-ton stone. The dike was built up to 

 +4 ft mlg with a 10-ft crest width and 1V:1.5H side slopes. The 

 crest width was 10 ft along a 250-ft section at the seaward end of 

 the east Jetty. The cost of the repairs was $43,500 using 4,280 tons 

 of stone and 725 cu yd of shell. 



1968 The Greater LaFourche Port Commission dredged a new 20- by 300-ft 

 channel about 300 ft west of the existing channel which was closed 

 after completion of the new channel (Figure 19). 



(Continued) 



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