Construction and Rehabilitation History
1960
ft mlg on the groin. Soil subsi-
the east jetty, and from 0- to
(cont.) dence was considered to be the major cause of jetty deterioration.
Seaward sections of the east and west jetties, 7 0 and 8 0 ft long,
0
0
ft mlg with a 6-ft top width and
respectively, were brought up to
side slopes. The 345-ft-long groin was repaired to an eleva-
mlg, a 5-ft top width, and
side slopes. Stone
tion of
size was determined from Hudson's formula for a 9-ft depth-limited
wave height. (The design called for the larger stones to be placed
on the outermost surface.) The ,000 cost of repairs included
sweeping (removing exposed rock, piles, etc. a 150-ft-wide section
along the channel side of the west jetty and placing about 4,000 tons
of stone.
1964
Repairs were made to the groin and sections of the east jetty. The
landward ends were extended, making the east jetty and groin 1,250
and 630
long, respectively. These extensions were needed due to
continued recession of the shoreline, which resulted in flanking of
ft mlg with a 6-ft
both structures. The groin was brought up to
top width and
side slopes, using 1- to 6-ton stone on the
seaward section and 200- to 2,000-lb stone on the 250-ft landward
extension. (A
bedding layer was placed also.) The east
jetty sections were brought up to
ft with
side slopes
using 1- to 6-ton stone. The top widths were 6 ft on the 275-ft
landward (including extension) and
middle sections, and 1 ft
0
on the 200-ft seaward end section. Prior to repairs, the center-line
elevations (September
were from -2 to
mlg on the
groin, from
to
mlg on the east jetty, and from
to
ft
on the west jetty. The total cost of placing 8,240 tons of stone and
600 lin
of sand fence was ,900.
1966
Repairs were made to the groin and east jetty, their landward ends
were extended 1 0 and 135 ft, respectively, and a 290-ft-long rubble-
0
mound dike was constructed along the shoreline, connecting the two
structures. The existing center-line elevations (December 1965
to
ft
survey) were from
to
ft mlg on the groin and from
mlg on the east jetty. The design geometries were identical to those
used in 1964. A
blanket of shell was placed along 200-ft
sections at the landward ends of the structures and along the dike.
These sections were completed using 500- to 4,000-lb stone, and the
remaining repairs used 1 - to 6-ton stone. The dike was built up to
side slopes. The
ft mlg with a 10-ft crest width and
crest width was 1 ft along a 250-ft section at the seaward end of
0
the east jetty. The cost of the repairs was ,500 using 4,280 tons
cu yd of shell.
of stone and
1968
The Greater LaFourche Port Commission dredged a new 20- by 300-ft
channel about 300 ft west of the existing channel which was closed
after completion of the new channel (Figure
(Continued)
47
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