(Continued)
Construction and Rehabilitation History
Parallel bulkheads, consisting of wood sheet piles, brush- and
1917-
filled dikes, and fascine mats for scour protection, were constructed
1923
on the channel sides of the jetties. The bulkheads were spaced
apart. The east bulkhead (22,820
long) terminated at the
2,400
seaward end of the east jetty, and the west bulkhead ( 1 6 , 1 2 0 ft long)
terminated about 5,400 ft from the seaward end of the west jetty.
Total cost for the bulkheads (construction, scour protection, and
maintenance) was ,584,000. In 1923, the existing spur dikes were
extended and new dikes constructed, reducing the effective width of
the pass to 1,750 ft. This contraction, combined with dredging,
resulted in a 35-ft channel depth.
The east jetty was extended 1,100
to
and the west jetty
1921-
was extended 850
to
The extensions and outer ends of the
1923
jetties (approximately 2,900 ft on the east and 4,900 ft on the west)
were capped with concrete. Continued settlement and cumulative storm
damages had lowered these sections so that at high tide considerable
portions were submerged, allowing a significant (10 to 20 percent)
amount of overflow. Extensions and capping costs were 4,000 and
4,000, respectively.
During this period the jetties were maintained by placing concrete
1924-
capping and riprap stone (usually as a base for capping). As a
1937
sult of continued jetty subsidence, capping was required to maintain
flow between the jetties. During this period, most sections of both
jetties were capped twice with roughly 70,000 lin ft of concrete
placed over approximately 32,000 lin
of active jetty. (Landward
ends were essentially landlocked and required no additional work.)
mhw (or
ft mgl)
Concrete was placed to an elevation of
in lifts typically to 4.5 ft high. Widths of the cap varied from
about 6 ft at the seaward ends to 3
at the landward ends. The
total cumulative cost for capping and stone was
||content||
,170,000. In
additional spur dikes were placed along the outer 10,000 ft of the
jetties, reducing the effective channel width to about 1,400 ft.
This addition was done in an effort to entirely eliminate maintenance
is an east jetty cross section of cumulative
dredging. Figure
work done up to
in the general vicinity of
The east jetty was repaired at the following locations:
to
1938-
to
to
and
to
1939
Fascine mats (40 ft wide and sunk with 60 lb of stone per sq yd) were
placed on each side of the jetty to prevent scour. The section was
core stone and 3- to 7-ton cover stone,
composed of 50- to
ft mgl elevation,
crown, and
1.25 side slopes. A total of 24,300 tons of stone and
7,300 sq yd of mats was used. The seaward end of the east jetty was
capped with concrete. A base of riprap stone was placed to
long, and placed to
mgl, and the cap sections were 10 ft wide, 25
The total cost of the repairs was 2,000.
ft
(Continued)
27
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