The herald., 1897-04-04
THE PROPER POINT
Conditions at San Pedro Which De-
cided the Final Selection

The situation at San Pedro is more
complicated and the solution of the ques-
ton is more difficult. The entrance to the
inner harbor Is but short distance east
erly from Point Firmin, and the anchor
age ground is already we'll protected from
the west by the bluff which terminates in
this point. The east shore of Point Fir
min is rocky, and growth of kelp indi-
Gates that there are occasional rocks in
the bottom of the bay. There are also
reported to be littoral currents of some
force, whose possible action must not be
overlooked.
No currents other than tidal currents
were observed during the examinations
made under the direction of this board.
The weight of evidence given in connec-
tion with bodies that have either fioated
or rolled along the bottom, was in favor
of a littoral current close in shore from
west to east, while 1t is generally adj
mited that there is a current along this
coast from east to west. The natural
effect of q shore current passing along
duce eddy currents in an opposite cirec-
ton, but such an eddy current is liable to
be broken up or changed by any
obstruction which may ~ materially
alter the shore line. The break
water must be so located as to
Snlelu tne protecteu urea rum INC sou,n
western swell now reaching it, though
that swell gives little trouble to the pres
ent harbor entrance, and SO as to
shut off the sea which is
now produced by the southeast winds,
both from the anchorage areas and
the entrance to the inner harbor. Fur
thermore, this breakwater must be locat-
ed in accordance with the provisions es-
tablished for a deep water harbor at least
1000 feet seaward from the seven fathom
line. Three rivers, the Los Angeles, the
San Gabriel and the Santa Ana, all of
which in seasons of flood bring down a
considerable amount of sand or silt, dis
charge into San Pedro Bay, though the
material which they deposit is not carried
very far beyond the place where it is first
dropped. The current out of the tidal
basin. known as Wilmington Lagoon will
be discharged into the protected area.
While an opening which will allow the
southwest swell to enter the protected
area may be Objectionable, 1t has been
thought best to have an opening SO locat-
ed as to avoid this danger, but through
which littoral current can pass in either
direction whether it be the current which
is now thought to exist or new current
created more or less by the existence OF
the breakwater and which will tend to
prevent the fouling of the harbor by sew
age or other disturbing causes.
PROPOSED BREAKWATER.
breakwater which IS believed to meet
all these requirements has been located
and is shown on the map accompanying
this report -.
The effective opening between this
breakwater and Point Firmin varies with
the south; winds from this direction have
only a sweep of Is miles from Santa Cata-
lima Island. The clear opening to the
southwest swell is very small and what
ever swell enters must come over bottom
less than two fathoms deep. Should 1T pc
found necessary the southwest swell couiu
be entirely excluded by short break
water, hardly more than groin, built In
shallow water, on rocky bottom, little
east of the lighthouse. The opening lett
between the breakwater and the point is
| considered enough to pass current when
| will prevent the accumulation OF SAND IN
| the protected area, and prevent fouling
the opening would also in smooth weather
| he O convenient entrance or exit Tor light
draught coasting vessels.
| Eight borings were made on the line OF
| this breakwater. The eastern boring (SOO0
| feet from west end of breakwater) showed
! soft. fine sand, similar to that found at
| Port Los Angeles. In all other cases
gravel or hard clay was found with, in
| three instances, from one to two feet OF
| soft clay or mud, on the surface. The
material was SO hard that in eight borings
1t was not thought necessary to bore more
than six feet into the bottom. These
borinrs indicate excellent foundation for
this breakwater. 1t has not been thought
necessary to make any additional allow
ance for settlement beyond that included
in the contingent percentage. Some set
tlement may take place at the east end,
but not over length exceeding 1000 feet,
and if it should average five feet the extra
cost would be balanced by shorfening the
breakwater 150 feet. At the same time
an examination was made of the points