Table 3
Galveston Harbor Jetties
Galveston, Texas
Construction and Rehabilitation History
The first attempt at constructing jetties was begun by placing cement
covered gabions over distances of 9,700 and 2,200
on the north
1879
(Bolivar Point jetty) and south (Fort Point jetty) sides of the in-
let, respectively. An additional 500 ft of north jetty was con-
structed of timber piling at its landward end. The gabions were 6 ft
high and wide, from 6 to 12
long, and filled with dredged sand
once positioned. The jetties were submerged, extending no higher
with the majority from 5 to 6 ft below
than mean low water
mlw. The gabionnades were unsuccessful in either securing a deeper
navigable channel or in accumulating sediments in their immediate
areas. Various geometric arrangements of gabion placement were tried
but proved unsuccessful. The gabions tended to settle and move
laterally due to tidal and wave-induced water motions and related
movements of bottom sediments. This method of construction was used
due to lack of available stone and an inability to transport stone to
the inlet.
second attempt at a south jetty consisted of placing multiple
A
1885
layers of log and brush (fascine) mattress, each layer ballasted with
stone riprap. A total of 22,550 lin
was constructed with as many
as four layers placed. The majority of the jetty was submerged with
only its landward end above mlt. The mats were typically 1.5 ft
to 120
wide at the base with narrower mats (15 to
thick and
60 ft wide) placed in the remaining layers. Approximate y 400,000 sq
yd of mattress and 9,000 tons of stone (roughly 50
were
mattresses, settlement due to scour, and teredo damage had led to
Rubble-mound jetties were constructed and completed to lengths of
25,600 and 34,800
1898
on the north and south sides, respectively
The south jetty was built during 1887-1893 and
Figure
and the north jetty was built during
The jetties were
placed along the alignments of the earlier jetty attempts (the south
jetty rubble mound being placed on top of the remains of the fascine
mat jetty (from
to sta
converging in the offshore
direction to a distance of 7,000 ft. The jetties were built to
ft
(but as large as 20 ft at the
mlt, a typical crown width of 12
seaward end of the south jetty), and as steep as practicable side
at the seaward ends). The
slopes (typically
and up to
majority of the jetties were constructed using sandstone riprap
varying in size from 20 lb to tons. Granite blocks, varying in
size from 0.75 ton to 1 tons and more, were used as the cover layer
0
(Continued)
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