Table 61
Mackinac Island Harbor Breakwaters
Mackinac Island, Michigan
Date
Construction and Rehabilitation History
1914
Construction of a 410-ft-long east breakwater and a 950-ft-long west
breakwater (Figure 170) was completed. The breakwaters were rubble
mound with a crest width of 1 ft and an el of
0
ft lwd. Side
slopes were
1967
A 500-ft-long lakeward rubble-mound extension to the east breakwater
(Figure 170) was completed. The extension had a crest el of
ft
lwd and a crest width of 8 ft. Stone was placed on
side
slopes, and cover stone ranged from 3 to 5 tons at the breakwater
head and from 2.5 to 4.5 tons on its trunk.
The stone in the breakwaters has been replenished and replaced peri-
1986
odically during its lifetime, and the structures are presently in
fair condition. An aerial view of the Mackinac Island Harbor break-
waters is shown in Figure 171.
267
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