Table
Shilshole Bay
Seattle, Washington
Construction and Rehabilitation History
The project was adopted for the boat basin and a 4,200-ft breakwater.
1954
The breakwater was completed. The breakwater was constructed of
1958
dredged sand-fill between mounds of Class
rock which form the
breakwater toes. Mounds were
above the ground line but not
higher than -10 ft mllw to avoid disturbances during low tide periods
during construction. A 3-ft-thick layer of gravel was placed over
the dredged fill and used as a filter between the rock toes and the
rock was placed over the Class
fill. Class
rock to a 1 :1.5
finished slope, with a minimum thickness of 5
where it is exposed
to wave action and 3 ft where it is covered by Class
rock. Class
armor rock weighing 1,500-3,000lb was placed on the slopes to
-10 ft mllw elevation. The breakwater crest was at +20 ft mllw; the
breakwater was designed to withstand a
5-sec wave.
240-ft-long rubble-mound extension was added to the existing
A
1961
breakwater.
The harbor and cross sections of the breakwater are illustrated in
1985
168
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