Table 50 



Pentwater Harbor Piers 



Pentwater, Michigan 



Date(s) Construction and Rehabilitation History 



1868- Construction of a 606-ft-long north pier (Figure 136, Sections B, C, 

 1870 D, and E) and a 620-ft-long south pier (Figure 136, Sections B, H, 

 and J) was completed during this period. The shoreward 439 ft of 

 the north pier was constructed with woodpillngs (Figure 137, Sec- 

 tions D and E) that were spaced 14 ft apart and stone filled. The 

 remaining portions of the north pier and the entire south pier (Fig- 

 ure 137, Sections B, C, J, and H) were constructed with stone-filled 

 timber crib structures. The width of the timber cribs at the north 

 pier (Sections B and C) were 20 ft, and the south pier timber crib 

 structures (Sections B, H, and J) ranged from 20 to 32 ft in width. 



1872 The north pier was extended by 34 ft (Figure 136, Section A) with a 

 timber crib structure. The pier extension was 30 ft wide and filled 

 with stone (Figure 137, Section A). 



1887 The south pier was extended by 101 ft (Figure 136, Section G) . The 

 extension included a 30-ft-wide stone-filled timber crib structure 

 (Figure 137, Section G) . 



1938 The north and south piers were capped with concrete and stone super- 

 structures (Figure 137) . The crests of the piers were Installed at 

 an el of +7.0 ft Iwd. The piers ranged in width from 18 to about 

 37.5 ft. The widths of two portions of the north pier (Figure 137, 

 Sections A and C) were increased by Installing woodpillngs on the 

 channel side and filling the voids with stone prior to capping the 

 structures. 



1959 A 60-ft-long rubble-mound extension to the north pier was completed 

 (Figure 136) . The structure had a 10-f t-wide crest width and an el 

 of +5.0 ft Iwd (Figure 137). Side slopes were 1V:2H, and 9-ton (min) 

 toe stones were utilized. 



1971 Riprap stone was placed around the head and on the lakeward side of 

 the rubble-mound portion of the north pier (Figure 136) , and stone 

 replenishment and regrouting was completed for the remaining portion 

 of the north pier (Sections A, B, C, and D) . Riprap also was placed 

 around the head of the south pier, and fill stone placement and re- 

 grouting were completed for Section B (Figure 136) of the south pier. 



1981 Riprap was placed along the lakeside of a portion of the south pier 

 (Figure 136, Section H) . 



1982 Small core stone was placed into gaps of the rubble-mound portion of 

 the north pier (Figure 136) between the cover stones. Fill stone 



(Continued) 



220 



