Table 13
Fernandina Harbor Jetties
Fernandina Harbor, Florida, SAJ
Date
Construction and Rehabilitation History
1880-
As authorized in 1880, the north jetty was to be 18,000 ft long and
1913
the south jetty a little over 12,000 ft long. The crests were to be
at the level of mean low tide, except the outer 3,300 ft of each,
which was to be at midtide level. The River and Harbor Act of 1892
provided for a 19-ft-deep channel and fixed 3,900 ft as the width
between the outer ends of the jetties. The north jetty was first to
be raised to a height sufficient to retard effectively the sand
movement southward. The south jetty was then to be raised and ex-
tended as necessary to secure the desired depth over the bar. The
River and Harbor Act of 1896 provided for raising the jetties to mhw
(+6 ft mlw) ,
Jetty construction methods were in many respects similar to those
used on other regional projects built during this time. The jetties
were built using alternate layers of stone and log mattresses, as
many as eight courses being used in some sections. Built initially
at and below mean low water, the jetties were subsequently extended
and raised (using rubble stone) over a period of several years.
During construction, the south jetty had sections removed to allow
the then existing channel (and shipping) to pass through it. The
1903 Annual Report to the Chief of Engineers stated that, except for
a few low places where settlement had occurred or stones had been
displaced by wave action, the north jetty was completed to the
(approximately its
elevation of high water from the shore to
present outer end). It stated that the inner slope between
had been reinforced with riprap, as the difference in
and
head between the water inside and outside was so great that flow
through the jetty caused dangerous scour at the base on each side.
In 1903 the south jetty was completed to the elevation of high water
for 7,500 ft of its length, to -5 ft mlw for the next 3,500 ft, and
a 60-ft-wide apron was placed against the inner slope from sta
to
The jetties were completed to mhw in 1905, the north and
The seaward ends converged to a distance of 3,900 ft and were
parallel over the final 1,500 ft of their lengths. After 1905
considerable repair work was done on the jetties to raise subsided
sections and replace stone carried away by storms. These repairs
were made from time to time up to 1913.
Work under contract to repair both jetties began in February and was
1926-
completed 1 year later. This repair resulted in raising the north
1927
ft mlw. In each case,
ft mlw and the south jetty to
jetty to
the crest width was 8 ft.
(Continued)
39
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