Los Angeles daily herald. [volume] (Los Angeles [Calif.]) 1873-1876, 1874-03-31
A New and Important Feature In
the Development of Wilmington
Harbor.

Horpof.
1t has been heretofore supposed that
the bed of our harbor at Wilmington
was deep soft mud, and that in the
future improvement of the ship chan
mel an expensive system Of sea-walls
would be needed to prevent this soft
mud from settling down and refilling
channels and docks when they had
been cleared. The prosecution of the
work of the new wharf company has
thrown an unexpected light upon the
subject, and shown that instead of
mud, the bed of the harbor is a firm
clay that will neither wash nor settle.
The slope of this stratum of clay is
from the land out toward the sea.
This explains the fact that the ship
channel lies, through almost its entire
length, upon the outer side of the har-
Dor, hugging the shore of Rattlesnake
Island. At first sight this position of
the main ship channel along the outer
edge of the harbor, with broad flats of
a stiff clay, almost entirely bare at low
tide, separating the channel from the
main land, would seem serious bar
to the Improvement of the harbor, ne
cessitating the construction of long
wharves to gain at the end of each
wharf only limited accommodation
for ships. Here comes in, however,
the new feature of which we have
spoken. 1t is found that branching off
from the main ship channel, like the
branching arms of river, are num-
Der of side channels almost like the
worn beds of old water courses. There
are probably dozen of these arms be-
tween the present railroad wharf and
the bluffs below, each arm or slough
reaching from the navigable channel
almost or entirely back to the main
land. The long continued action of
the tide has gradually filled these an
cient channels with q soft mud, al
most as liquid as water, leaving the
firm banks of clay standing like sea-
walls on either side SO that when once
the soft mud is cleared out no pile work
or walling will be needed to preserve
the shape of each channel. The new
wharf company cross with their work
the first and shoalest of these side
channels $50 feet back from the main
channel. Mr.. Jones, superintendent
of the company, says that an iron rod
sank with its own weight seven feet
through the mud. These sloughs be-
low the first gradually increase in
width depth and length, some ex-
tending back distance from the
ship channel Of 1900 and 1850 feet
with width of several hundred feet
and depth of fifteen to twenty feet
at low tide. The wharf company make
use of two or three sloughs besides
frontage upon the main ship channel
between the mouths of the two sloughs
of several hundred feet. The first
slough, which they are now crossing,
will give basin $50 feet in length,
with width for several vessels to lie.
The second slough has length of
more than 1000 feet with width at the
commencement of 800 or 400 feet and
depth of the soft mud of about fifteen
feet at low tide. The company can
make available at a limited expense
water frontage of probably 1900 feet.
Nature has already provided in these
series Of sloughs the outline of an ex-
tensive system of docks that will
double the original frontage. Here,
too, plan at once suggests itself for
the rapid and cheap and at the same
time permanent improvement of these
docks. These flats, as before stated,
clear out to the main ship channel are
simply stiff, firm clay, solid almost
as cement, cut at right angles at inter-
walls of a few hundred yards by sloughs
of soft mud that reach from the navi-
gable channel back almost to the shigh
ground. Instead of building a road
way of earth down the side of the
sloughs run double line of piles
Fence posts would almost answer) such
distance apart as may be desired for
the width of the roadway. No fear of
the teredo destroying them as the clay
in which they stand is bare at low
tide. Then plank up the sides to the
level of high tide. Here are simply
couple of strong board fences 40 or SO
feet apart. Now set the dredging ma
chimes at work, letting it dump the
soft mud of the slough over the fence
into the enclosed area.
Two ends are accomplished; the
roadway is built at less cost than if
the dirt has to be hauled, and the
slough is dredged for ships at about
one-halfthe ordinary cost of dredging,
as the mud does not have to be re-han-
died, and no steam tug is needed to
tug lighters.
Yet after the roadways are filled
there will still remain considerable
mud in the channel, and it is desirable
to prevent any further deposit of mud
by the slow action of the tide. Stop
moment and notice! The building of
the roadways for each slough has left
between it and the slough next be-
hind, or back Of it, tidal basin of