New Orleans Republican. [volume] (New Orleans, La) 1867-1878, 1871-07-18
PROTECTION LEVEE AND CITY
DRAINAGE.

Plan Proposed by J. Edmonst0n, Civil
Engineer, TO Protect the City Against
Floods of the Mississippi and High
Waters of Lake POntchartrain-Drain.
age of the City and Reclamation of
Swamp Lands Between the City and
| Lake.
To secure the city from overflow and
etfectually drain it, the lake shore levee
and reclamation of the interjacent swamp
should be consided a sine qua non.
Simply connecting the Metairie and Gen
| tilly ridges with the river by artificial
| levees, and embanking the New canal and
Bayou st. John, will not secure the city
| from overflow without connecting these by
| traverse levees with an embankment earth
work properly constructed along the lake
shore, and the draining of the Intervening
swamp; the outer slope of the earthwork to
be protected with proper facings-not a
wall of concrete and brick masonry or iron
revetment, but of other more adaptive and
and less expensive material to resist the
heavy swell or action of the water, and To-
| Gated sufficiently inland to give a long slope
TO receive the swells made by gales or heavy
! storms.
For the lake shore embankment no wall of
concrete, brick masonry or iron revetment
| is required, inasmuch as it is not proposed
TO build dyke breastwork to resist the bill
cOntine within shore the placid waters of
the lake.
Ii 1t would pay, or rather if Mayor Flan-
ders would pay engineers for any well di-
gested report upon the question of a suita-
able protection levee along the lake shore.
1t might be demonstrated that wall of con-
crete or brick masonry, or earthworks with
iron revetments, as a structure for the pro-
lection levee along the lake shore, is a prop
osition SO far beyond the requirements of an
efficient embankment protection, that even
though the City Council had in its Golfers
the trile of 100000, which under the
project of the Canal and Levee Company
such protection levee would certainly cost,
it would be hardly advisable to venture to
commit the city TO the CARVING out of such
questionable plan.
Overlooking the necessity of a protection
levee along the lake shore, and that of
draining the interadiacent swamp, Don
Juan POye, Spanish engineer, tried the
plan of connecting the Metairie and GENTLY
ridges with the river by al tifcial levees
and thus protect the urban part of the city
from overtow-the plan proved a disastrous
failure.
After the first settlement Of New Orleans
by the Spanish it is well known that during
a heavy easterly gale the gulf rose TO an un
precedented height, forcing its waters into
Lake Pontchartrain, raising the surface of
the lake six and half feet over its mean |
level, nearly inundating New Orleans. The |
lake is continually subject TO overflow
during heavy easterly gales by floods from
the gulf, hence the necessity OF protection |
from its high waters.
LEvEE EMRANENENT.
Beginning at "a point near the intersection |
of the upper line of Carrollton with the |
Mississippi, construct a protection levee |
with height OF three feet above the high |
.o,1- %
width of base and side slopes viz: six to |
one of vertical height along said line, inter-
secting the Metairie ridge, thence to a
point near the New Orleans canal, thence |
along or near said canal to Lake Pontchar-
train, thence along or near the shore of said
lake to a point of intersection with La
fayette avenue, thence along said avenue to
its intersection with the Bayou Savage and
Gentilly ridge. The outer slopes of the
levee embankment to be protected bv
proper facings, forming a natural and solid
embankment. lmpervious to water.
To drain the city and its suburbs in the
rear, cross canal is to be excavated along
the edge OF the swamp conterminous TO the
rear OF the city, beginning at point near
the line of the Elysian Fields and Pontchar-
train road, to be designated by the en-
gineer; thence along the rear of the suburbs
of the city on a line with the edge of the
swamp TO its junction with St. Johns bayou;
thence along the line in the rear OF the CITY
to its junction with the New Orleans canal
at a point to be designated by the engineer
The localities, course and connections of
the man arteries or receiving canals to
drain the city and swamp have been
shown. viz: The New Orleans canal, the
main receiver cross canal Bayou ST. John,
Bayou Salvage, connecting with Bayou
Blenvenu. The process of draining the
city, its suburbs and the interiacent swamp
area will now be indicated.
DRAINAGE.
Or the outline rear of the citv confer
minous to the swamp line cut a cross canal
from point near and within the upper line
Of embankment levee, to point intersect-
ng Lafayette avenue OF twelve feet depth,
fourteen feet width of bed and twenty-four |
feet width of surface, intersecting the New
Orleans canal, Carondelet canal and Bayou
at points to be designated by the .
SAID cross canal to connect with ,
5wo dlscharging canals at points designated,
extending to the lake. each of eight feet 6
1epth and twelve feet width, with proper
lde slopes graded with declivity toward I
he lake OF one in two hundred and making
unctlons with the main receiver canal
llong the lake shore, at points to be desig {
lated by the engineer.
DRAINAGE OF THE CITY. ;
Along the lowest surface levels within the
SoA Va ivy Sub utUdCueu W
connect with the city canals at points to be '
designated by the engineer. These trenches
# six feet depth and eight feet width, with
nner slope, sides to be inclosed with wood
ail1ng, and to connect also at points desig-
ated with the cross canal along the out
inc OF the city and the edge of the swamp. '
The cutters of the city from two to two a
nd half feet depth, with grading of one t
4 two hundred, connecting with culverts
t the street crossings of four feet depth and
nd four feet five inches width. to be y
leaned out daily with SCOOP shovels and h
Overed with patent cast iron plates or
eavy planking. The streets along their
entire lines to be raised sufficiently to give n
roper slope toward the cutters 6
Clear the swamp of the matted under
rowth between the city and the lake; cut O
anals OF sufficient width and depth, through G.
le swamp and marsh, connecting the city n
nd the lake, and traverse intersecting o.
'enches one-eight of a mile apart; the in .
ervenIng swamp and marsh entirely
eared of all underground, the rapidity of
would be increased and the u
eight OF freshets rapidly decreased The Al
learlng and removal of the underground, 8.
lie softenlng OF the earth thereby, would :"
ause heavy rains to be rapidly absorbed, II
nd the exposure of the surface to the sun
ould rapidly increase evaporation. The
ltervenlng swamp thus cleared, the cross | Il
,ction canals and transverse trenches all :;
with the city and the lake, u
ded by rapid absorption and evaporation a
heavy rains, would speedily drain the t.