New Orleans Republican. [volume] (New Orleans, La) 1867-1878, 1875-01-31

Il weeks, of which eight days were employed
IN examinations of the months Of the Miesis-
sippi river, and at the site for q canal pro
posed by Captain Howell.
After this history of the proceedings Of
the board, the conclusions reached will be
| given.
I.-CANAL.
A number of locations for a canal were
considered by the board, among which may
be mentioned the one proposed by Captain
Howell, near Fort St. Philip; one leaving
Pass a-POutre six miles inside its bar, and
running north into deep water; one leaving
Southwest Pass about six miles inside OF its
bar, and running east into deep water, aud
one obtained by closing the South Pass at
canal and lock by. Southwest Pass, and
opening it's mouth by dreding, the mouth
being protected by jettles.
The advantage of the sites at Southwest
Pass and Pass q POutre are, that the differ
ence OF water level at the two ends of the
canal will rarely exceed q foot, and may
often be SO email that the use of the lock-lift
would be unnecessary; that the canals
would be only about three miles long. and
being near navigable passes, all light
draught vessels would go through the
passes; and that these canals would debOuch
| into deep water at once, while at distance
| of six miles from the Gulf outlet Of the Fort
st. Philip canal there are only twenty eight
feet Of water at low tide.
The objection to the site at the Sou hi
west pass is that its debOeche would gradu-
| ally slit up in the entrance of the delta,
| ana that the cost Of the harbOr covering its
| entrance would be excessive. The same
objection OF excessive cost for protection of
entrance applies to the site at Pass a.
rOutre. while the proposed outlet of the
Fort st. Philip canal is largely protected
by Sable Island, and does not need expen-
sive works to cover its entrance. The sites
below the head of the passes do not give
the Same promise of permanence as that near
Fort st. Philip. The plan of canalizing tie
South pass would involve the difficulty Of
opening and keeping open its mouth, which
is the main difficulty should jstties De APP
plied.#
After careful consideration of the sew
eral sites that in the vicinity OF Fort St.
Philip was adopted, with one dissenting
member. Aside from the question of cost
it offers greater hopes OF permanence than
the other sites. It does not seem probable
from its present position at the head of the
proposed canal, and a comparison of the
fourteen foot curves at Sable Island on
Talcott's map of 1888 and Captain Howelps
map of 1872 show no important change.
The board decided then that the canal. for
which estimates should be made BY them
should leave the Mississippi at d point
about five and half miles below Fort
st. Philip at such an angle with the
river that vessels would be able to
enter it easily; that about mile from it's
beginning there should be basin of 1000
feet by $500 feet; that before reaching the
basin, and near it, there should be a lock
500 feet long between its inter silks, of
sixty-five feet clear width, and with twenty.
seven feet Of water ON its milter stills at
mean low tide; the part of the lock in the
vicinity Of the gates to be of masonry on q
piled foundation, with heavy grillage: the
rest of the prism of the lock to be of earth.
with reverted slopes of one upon one; guard
gates to be placed above and below the
lock; the canal to be 200 feet wide on the
bottom, twenty.seven feet deep at mean low
water. and with side slopes of one-half for
one vertical on two horizontally, allowing
these to hatten if they will 1.-THE bank Of
Cnbetts gap stands on a slope of nearly
leaving the basin, the canal to run in q
straight line to the little bay between Sable
point, beginning to widen when it reaches
six feet OF water in the gulf, and widening
to l4o0 feet at twenty-fOur feet of water.
beyond the depth of twelve feet in the gulf:
the canal to be without banks. As, in spite
OF every precaution, accidents might occur
" AiSA WOuAO ludAo IL lIuDOSslOlo TO Use The
lock for considerable period of time. a
second entrance from the river to the basin
should be begun az soon as the canal is COM
pleted; this second entrance having it's own
lock and guard gates. As there will be a |
tendency to silt up at the river end of the |
canal, and also in the cut at the other end.
leading to deep water in the gulf, some |
dredging will be necessary. Should that at !
the gulf end prove large, it might become |
ad visable to build dykes along the sides of !
the cut. The cost of the dredging and the |
cost OF working the canal have been capi-
talized, and added to the first cost in the |
following estimate:
The first cost Of the canal complete is
The annna ca ~ =; 1884, 500
timated at $50 1856, which, capital.
'1eu d i've pei cent'....'............ l2l7, 100
Giving for the sum needed to build and
maintain canal. Sll 5l42OO |
Ihe canal is about six miles and half
ong, passing through q country of which
10 part is more than three feet above tide.
IND much OF its route passes through shall
ow lagoons. At two or three feet below
he surface, the delta at and below the site
i the canal is everywhere of blush mud
II clay. into which pole can be thrust. by
land, from five to fifteen feet. On the bars
he wave action has shifted out and left the
oarser sand in thin layers, and such strata |
erhaps from the same cause. are found
lsewhere in the delta
behring's 100 feet deep show the same CLAW. |
ecomlng more compact, and mixed with |
sand. At Fort st. Philip canal.
Nv water of the river is seven .tenths of a
,Ot above the mean level Of the gulf. and
Ugh water seven feet above the same plane.
is estimated that high water OF storms at
able point ls sometimes seven feet above
can level OF the gulf. The lock is there {
re planned tor lift of seven feet; but as 1
le water at Sable point will never be high
than that OF the river at the other end of I
10 canal, except for few hours during t
oient storms. no provision is made for
cklng down into the Mississippi. Guard
ties near the lock are provided to prevent G
lrrents rushing i'll either direction through o
Q canal. y
For details as to plan of canal and esti- f
ates see appendix A. v
One member is Of opinion that the site for " !"
nal between the Southwest Pass and East bav D
a decided advantage over the Fort st. Philip II
H-DEEPENING NATURAL OUTLET. t,
The methods which have been proposed Al
opening passage through bar at one al
the mouths Of the Mississippi are two: p
FIRST, BY stirring up in some way the ma d
lal OF the bar SO that the current shall 81
eep 1t away into deep water. NJ
second, by combining a mouth of the river fo
Jstties on the bar, so that aided, if neces. 10
y, BY dredging or stirring up, the water m
vi be able to scouD channel through 81
, bar, and maintain it when once formed. th
Judging from the results thus far obtain. st
the board is of the opinion that no fr
nissible expenditure of money can Der. WI
nently maintain by the stirring process ay
epth OF twenty feet at mean low water m
the mouth of the Mississippi and as they l0
not consider this an adequate depth, be
= deem the first process named inadmis- ba
lie. tel
q considering the method by jetties, it pu