Table 19 



Channel Islands Structures 



Channel Islands Harbor, California 



Date(s) 

 1959 



1960 



Construction and Rehabilitation History 



Construction of two rubble-mound jetties was completed at the har- 

 bor entrance (Figure 25). The north jetty was 1,270 ft long, and 

 the south jetty was 1,300 ft long. Crest els of the jetties were 

 +14 ft mllw with 16-ft crest widths. Side slopes were 1V:1.5H. 

 Cost of jetty construction was $817,000. 



Construction of a 2,300-ft-long detached rubble-mound breakwater 

 was completed for a cost of $2,619,000. The crest el of the break- 

 water was +14 ft mllw, and it had a 16-ft width. Side slopes were 

 1V:1.25H on the harbor side and 1V:2H on the ocean side. This 

 structure was constructed to form a sand trap in conjunction with 

 the existing jetties. Initially, 1,600,000 cu yd of material was 

 dredged in the lee of the breakwater and then biennially for 

 deposit south of the harbor entrance for use in restoring and 

 maintaining the downcoast shoreline. 



1986 



The structures are in good condition. 



Figure 25. Channel Islands Harbor, 

 California 



47 



