Table 23
Los Angeles and Long Beach Breakwaters
Los Angeles and Long Beach Harbors, California
Date(
Construction and Rehabilitation History
1898-
Construction of the 11,152-ft-long San Pedro Breakwater occurred at
the site (Figure 29). The harbor side of the structure was built
side slopes, while the ocean side consisted of
with
slopes from the bottom up to an el of -12 ft mllw. At this point
the slope changed to
to an el of 0.0
mllw. The rubble-
mound portion of the structure (Figure 30) was
ft wide at el
mllw. Granite blocks (up to 20 ton) were laid in courses to
0.0
an el of +14
with a crest width of 20 ft. The rubble-mound
portion of the structure was constructed with 8- to 10-ton stone
and was permeable. Other structures, which are now incorporated
into the inner harbor works, were constructed as early as 1871.
Construction of the 18,500-ft-long rubble-mound middle breakwater
(Figure 29) was in progress. The breakwater had a 16-ft crest width
1938
at el +14 ft mllw. Side slopes on the ocean side were
and on
(Figure 30). An
the harbor side ranged from
to
impermeable core was installed from the bottom (approximately
-50 ft mllw) to el -26 ft mllw.
1942-
Construction of the 13,350-ft-long rubble-mound Long Beach Break-
1960
water (Figure
occurred during this period. With the exception
of the breakwater core el (Figure 30) the cross section of this
structure was similar to that of the middle breakwater.
1947
Repairs to the middle breakwater were accomplished for a cost of
6,
Winter storms resulted in extensive damage to the San Pedro Break-
1983
water. The structure was breached in an area immediately seaward
of the curved portion of the breakwater. Model tests were con-
ducted after the damage (Carver 1984, Baumgartner, et al.
and restoration of the San Pedro Breakwater was subsequently
completed. Work consisted of the placement of approximately
25,000 tons o f salvage stone and new angular stones ranging from
15 to 25 tons each. Where voids occurred on the crest after this
stone placement, concrete was pumped into flexible temporary forms
to complete the repair.
1986
The breakwaters presently are in good condition.
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