trend exists for the sand size to become progressively smaller from foreshore 
to offshore. Average median diameters are 0.34 millimeter at the foreshore, 
0.28 millimeter at depths of 5 and 10 feet, 0.23 millimeter at depths of 15 and 
20 feet, and 0.18 millimeter at depths of 25 and 30 feet. Dune and bluff sand 
is somewhat finer than the foreshore sand, but coarser than the lake bottom 
sand. There is little systematic variation in sand size with distances from 
the breakwater. Sorting ranges between 0.28 and 0.40 phi, indicating very good 
sorting; sorting varies little between dune, foreshore, and the 5-foot depth 
and becomes poorer toward deeper water, reaching approximately 0.40 phi at 
depths of 20 and 30 feet. 
b. South of Holland Harbor. The majority of the sands from the dune, the 
bluff, the foreshore, and the lake bottom on the south side of Holland belong 
to the fine sand category. Generally, only minor differences exist between 
average sands from the north and the south sides of Holland. The average bluff 
and foreshore sand consists of 85.1 percent fine sand (finer than 0.42 milli- 
meter) and 14.9 percent medium sand. The average lake bottom sand consists of 
94.7 percent fine sand and 5.3 percent medium sand. Median diameters decrease 
from foreshore toward offshore, about 0.25 millimeter at depths of 5 and 10 
feet, about 0.20 millimeter at depths of 15 and 20 feet, and about 0.16 milli- 
meter at depths of 25 and 30 feet. Dune and bluff sand is finer than the fore- 
shore sand but coarser than the lake bottom sand. The lake bottom sands are 
distinctly coarser immediately south of the harbor and also along lines 11 and 
12 (Fig. 13), about 6,000 feet south of the harbor. Sorting displays a wider 
scatter than on the north side of Holland, ranging between 0.3 and 0.5 phi. 
As on the north side, sorting becomes poorer from foreshore toward offshore. 
The principal sources of littoral material are the beach and the bluff. 
Generally along eastern Lake Michigan, and particularly near Holland Harbor, 
the supply of littoral material from major inland water runoff is negligible. 
For this reason, the long-term geologic trend appears to be for sediment from 
shore erosion to fill in the lake. 
c. Shoaling and Dredging. Shoaling and dredging records indicate that the 
annual shoaling in the entrance channel of Holland Harbor averaged about 25,000 
cubic yards for the period 1965-70. The pattern of accretion shows some yearly 
variation and indicates that material encroaches into the entrance area from 
both north and south. In addition, the relative amount of drift from north 
and south appears to vary from year to year. Figure 16 shows conditions at 
the harbor entrance before dredging in 1973 and 1974. 
4. Meteorology. 
The dominant factors are winds, waves, and water level variations. The 
winds and waves are directly responsible for sediment movements, and fluctua- 
tions of water levels separate the regimes of the two areas affected, i.e., 
the backshore above the waterline and the foreshore below the waterline. 
a. Winds. Winds are a dominant force affecting the Holland Harbor area; 
they produce a number of major effects by (a) generating a force for waves, 
(b) causing lake level changes, and (c) transporting sand across the beaches, 
particularly the finer sediment sizes. Wind data (available from ship reports) 
over the southern half of Lake Michigan (south of 44° N.) show that more than 
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