The daily crescent. [volume] ([New Orleans, La.]) 1848-1851, 1851-08-05


The great object Of the Delta survey in question,
is to ascertain the most sdectusl method, and the
most suitable direction, for conveying the surplus
Aood-wstess Of the Mississippi wheihss iatsfaily
from, or downward in, the maip chsnnsl; and Of
discharging the same, with the least possible OBJ
structioas, into the open gulf; and IN such man.
ner g to- check, reduce, and prevent, ~ fer u
possible the cverfows 70 which the bottoms, fats,
and swsmps, in rear Of the natural lsvees,a now
exposed Or in the express language Of the official
instructions given u.s. !" 10 decide upon the extent
and character Of the surveys 10 be made upon
which judicious plans can be predcatsd, adapted
adequately TO control the inundations, and to pro-
efects." -
With this object in view, we take. leave 10 pro-
pose the following details OF operations as leading
Items OF the surveys, ETC., to be accomplished in
such order and to such extent as may be found
most convenient and practicable, viz:
/. Assuming the surface Of ordinary low tide Of
the gulf as the plane Of reference for all Of the sur.
veys, and the surface Of ordinary high tides as the
level OF al water discharges from the main river,
and all of its outlets, bsyous etc., the entire hydro
graphy, embracing. bays, inlets. lakes, bayous,
swamPs, etc., within the assumed Delta district,
should be carefully determined and delIneated in
suck manner as to exhibit the form, extent and
relative positions Of all such wster-sheets and
especially the extent and boundaries limiting the
flow Of ordinary high tides from the gulf inland.
=. Regarding all the water. sheets or fields allud-
documentary deposi,. Of the river Their .sv.,.I
capacitie. below the .urf.ce NJ ord;n.,v h;gh ia.
should be carefully determiued bv he reouiate
soundings and surveys usually required for such
purposes.
! s. One or more standard lines. at the discretion
of the directing engineer. should be carefully made
With chain, compass, and level. and designsted bv
suitable demarkations bench marks. ETC.. entrely
across the Delta district, below the mouth Of Red
River, and in such manner and direction thai II
may be referred To "A the basis of .uhordic,te
veys, Offsets ETC. Il being under.tood th.t ali ,va,s
courses pond. nool. etc ,r.ysrssd hv ear .ni
every line ara To be cs,ef,v noted ma deI;rs.,ed
A. One or more lines. similar in ali repeots to
those specified in the precedinr item sbouid aso
Be run across that portion Of The Delta district
situated between the mouth of Red River and tha I
Of the Arkansas i
S. Moreover, similar lines should also be run
across the same district above the mouth Of the
Arkansas, extending from the foot Of the upland
slopes, the west side Of Black and White rivers,
across In Msss.inn 10 The has. of The Iii. ...,
ward of Yaxoo river. :.
g. The relative levels Of all these lines should be
carefully determined by one or more lines Of refer
ence extended in some appropriate and convenient
direction from each basis line to the nearest point
or points Of the tidal plain mentioned in item first
z. Subordinate lines of similar character should
be run southwardy and northw wardly from the
several transverse or standard lines above specified
in such frequency and directions. and TO sucb ex.
tent, as may be found needful to determine the
features of the whole Delta, both in geographical
and hydrographical point Of view.
8. The subordinate lines between the mos,
southerly standard line and the gulf shore shoud
be extended downward or southward, as nearly as
practicable to the level Of high tide, and OCCASION
ally to the open gulf whenever such extensions are
deemed expedien. and practicable.
9. The transverse sections Of all bayous and
water courses leading out Of the Mississippi should
be carefully determined. as also of ali masses
through which their extraversated waters are con.
yeved 10 the gulf ""'s-' "'' ''"-
10. A transverse section of the Mississippi river.
in the vicinity of New Orleans, probably few
miles above, should be determined with the utmost
care and precision, including all subordinate Sec
items at the same point, from the lowest to the
highest water surface of the river, not exceeding
the height Of the natural banks of the river and in
such manner as to exhibit with accuracy ali tn,
subordinate sections to every rise Of one foot from
the lowest 10 the highest stage contemniaied 40
above. ''"'ApA''D "'
IL. The average velocity of the river currents.
corresponding to each of the different STAGES above
designated, should be determined with tSe u,mo.t
precision and the duration Of each stage. for al
least one entire year, should be carefullv observed
and noted, in months, days, and hours, for the pur
pose Of determining as nearly as practicable the
aggregate annual duration of each stage the
~ water con,evsd .onn",'. .ts 1so; "I aAicuu'
channel from New Orleans to the gulf and more
especially the magnitude Of the larpest volume th.,
can pass in the channel from Nee O,iear. n ~.
| gulf without overfiowing ;ts hank.
H. A small ouantitv Of water .bould ba ,,k.r
/ from the main channel Of The river ~ each an,
every stage DESIGNATED in the preced;ng item e.,
the purpose of having II c,ref,IIv .n.lv,sd =, a..
Grating the earthv matter beld in .nsrcn,on hv *,
| water in each stage. The .ensrat;on .honia +.
carefully and skilfullv made. for The purnose =
| determining the quantity Of sedimen,arv matte
| conveyed downward in each stape. and The annna
| amount conveyed BY the river from New Orlean,
| to the gulf. -
13. A transverse section of the Mississnp; .t tb
most suitable position below the month of Re,
| River, probably near the Raeourci cut.oT .houI,
also be ascertaned with equal care for the purnos
Of determining nearly as practicable the ouantit
| Of water conveyed downward bv the river in II
highest stage at that point-the average veioc;tv
the river currents in the highest stage al this sec
ton having been determined by careful Observation
for this purpose.
IA. The difference between the Quantities @
water flowing through the full section last men
toned and the full section contemplated in m
tenth item should be ascertained bv subtracting m
less from the greater quantity. This dfferenc
will show the quantity Of water that ought to b
discharged from the Mississippi between the tw
transverse sections, in order to prevent the rive
from overfowing its banks at and below Ney
orleans:
To- The positions, capacities, and number {
outlets or waste weirs, necessary to the dischare
Of the difference above mentioned, or what may
called the surplus waters OF the Missouri from tn
l main river channel on either side. in proporton