Brazos Island Jetties
Brazos Island Harbor, Texas
Construction and Rehabilitation History
Unsuccessful attempts to stabilize the pass and provide a navigable
channel were undertaken during 1882-1 8 and 1926-1928. These
improvements were authorized by River and Harbor Acts of 1 8 -1 8
and 1919. Construction of a south jetty was started in 1 8 by
placing alternate layers of brush mats and
clay bricks. The
bricks did not provide sufficient ballast, and construction was
halted in 1884, The jetty, partially completed to a length of
3,955 ft, deteriorated rapidly during the next few months. During
a channel was dredged through the pass but was abandoned in
1906 due to excessive shoaling. North and south stone dikes (1,800
and 1,400 ft long, respectively) were constructed on each side of the
pass during 1926-1927. The dikes were not successful in securing an
increased channel depth (18- by 400-ft channel authorized).
The existing jetties (Figure 14) authorized by the River and Harbor
Act of 1930 were constructed near the locations of the
dikes to lengths of 5,370 and 5,092 ft on the north and south sides,
respectively, The jetties converge from their landward ends to a
spacing of 1,200 ft then run parallel for approximately 2,500 ft,
terminating at the -25 ft mlt contour. The typical cross section
consisted of a
crown width at
side slopes, a
to 4,000-lb core stone and 6- to 10-ton
riprap bedding layer,
capstone. The jetties were constructed with 418,200 tons of stone at
a total cost of ,741,000.
Stone aprons were placed near the outer ends of both jetties. No
details are available. Riprap stone totaling 7,400 tons was placed
at a cost of ,000.
Various sections of both jetties totaling 5,690 lin ft were repaired
using new core and cover stone and resetting existing cover stone.
Approximately 20,800 tons of new stone were used and 1,570 stones
reset for a total cost of 4,100.
The jetties were repaired using new core and 8- to 16-ton cover
stone, resetting existing cover stone, and capping with concrete.
The concrete was placed above mlw throughout the void spaces in the
cover layer, restoring the general crown elevation of the jetties.
Total cost of the repairs was 9,000 using 20,300 tons of stone and
and 3,580 cu yd of concrete on the north and south
jetties, respectively. 'The concrete capping extended from the
existing shoreline to the jetties' seaward ends (roughly 3,000
on the north and 2,000 lin
on the south).