Table 42 



New Buffalo Harbor Breakwaters 



New Buffalo, Michigan 



Date(s) Construction and Rehabilitation History 



1975 Construction of two breakwaters totaling 2,045 ft in length (Fig- 

 ure 108) was completed at the mouth of the Galien River. The outer 

 480 ft of the north breakwater (Figures 108 and 109, Reach-A) con- 

 sisted of a rubble-mound structure with a crest el of +9.0 ft Iwd and 

 a width of 12 ft. Armor stone ranged from 10 to 16 tons (12-ton 

 average). The adjacent shoreward portion of the north breakwater and 

 the outer end of the south breakwater (Figures 108 and 109, Reach B) 

 consisted of a rubble-mound structure with a crest width of 10 ft and 

 an el of +8.0 ft Iwd. Armor stone on this portion of the breakwater 

 ranged from 5 to 10 tons (6-ton average). The adjacent shoreward 

 portions of both structures (Figures 108 and 109, Reach C) involved a 

 rubble-mound breakwater with a crest el of +8.0 ft Iwd and a crest 

 width of 8 ft. Armor stone ranged from 3 to 5 tons (4-ton average). 

 The adjacent shoreward portions of the breakwaters (Figures 108 and 

 109, Reach D) included a rubble-mound structure with a crest el of 

 +7.0 ft and a crest width of 6 ft. Armor stone ranged from 2 to 

 4 tons (3-ton average) . All rubble-mound portions of the breakwaters 

 had side slopes of 1V:1.5H. The inner ends of both breakwaters 

 (Figure 108, Reach E) consisted of vertical steel sheetpiling with 

 an el of +7 ft Iwd. Riprap was placed on each side of the sheet- 

 piling for toe protection. The breakwater configuration was model 

 tested prior to construction (Dai and Wilson 1967) . 



1980 An inspection of the structures at the site indicated that voids 

 existed in the outer reach (Reach A) of the north breakwater and 

 minor settlement had occurred, particularly around the head of the 

 structure adjacent to the navigation lights. The remaining portion 

 of the rubble-mound north breakwater also consisted of many voids 

 with some stones deteriorating (cracking or crumbling into smaller 

 pieces) . The outer portion of the south breakwater (Reaches B and 

 C) , although in better condition than the north structure, also had 

 experienced some settlement and contained some gaps where waves 

 washing through the structure was noted. The inner portion of the 

 breakwaters was in good condition. 



1983 Stone was placed in the voids of the outer portions of each 



breakwater (Reaches A and B, north breakwater, and Reach B, south 

 breakwater. Figure 108). A site inspection in the latter part of the 

 year revealed that some of the smaller stone (used to fit the voids) 

 had washed out. Voids in the trunk sections of the breakwater 

 (Reaches C and D, north structure, and Reach C, south structure) 

 still existed along with settlement of 1 to 2 ft in some areas. 



1986 The structures are presently considered in fair condition. 



Maintenance repairs of the breakwater have been recommended but not 

 yet implemented. 



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