Table 16 



Big Bay Harbor Breakwaters 



Big Bay, Michigan 



Date(s) Construction and Rehabilitation History 



1960 Construction of a 471-ft-long east breakwater and a 787-ft-long west 

 breakwater was completed at the site (Figure 42) . The shoreward 

 269-ft-long portion of the east breakwater was rubble-mound (Fig- 

 ures 42 and 43, Section A). It had an 8-ft crest width and a +8-ft 

 Iwd crest el. Slopes on the lakeside were IV: 2H, and on the harbor 

 side they were 1V:1.5H. The structure was built around steel sheet- 

 piling which had an el of +2 ft Iwd. From this point lakeward a 

 steel sheet-pile structure extended an additional 170 ft (Figures 42 

 and 43, Section B) . The shoreward 547 ft of the west breakwater uti- 

 lized the same structure. The sheetpiling had a crest el of +8 ft 

 Iwd with stone toe protection on each side. The head of the east 

 breakwater consisted of a cellular sheet pile (32 ft in diameter) , 

 and the lakeward 240 ft of the west breakwater was constructed of 

 36-f t-diameter cellular sheetpile (Figures 42 and 43, Section C) . 

 These cells were filled with sand and capped with 2 ft of grout- 

 filled rock. Rubble toe protection was included also. 



1969 The east breakwater was rehabilitated. 



1979 An inspection of the harbor structures indicated that additional rip- 

 rap was needed on both sides of the west breakwater (Figure 43, Sec- 

 tion B) . The stone was eventually placed. 



1986 The breakwaters presently are in good condition. An aerial view of 

 Big Bay Harbor breakwaters is shown in Figure 44. 



75 



