The record-union., 1896-02-10
HOW TO IMPROVE RIVERS.
Duty Of the General Government in Re-
gard Thereto.
Relation of Levees to the General Prop
osition-Systematic Plans
Necessary.

necessary.
The question as to how far the Cen
eral Government should extend its aid
in maintaining the best regimen of the
navigab1e streams of our Government
has long been a question upon which
authorities differ
In the report OF the Mississippi River
Commission, dated February II, 1880,
a majority Of that commission report in
favor of maintaining the embankments
during flood season, as well as uni
form channel during low water. A mi
nority of the commission do not seem
10 regard the maintenance of leyees as
a necessary adjunct to the improvement
Of navigabIe waterways. The majority
of the commission say, regarding the
Importance Of levees and closing of
crevasses:
''Levees have never been erected upon
the banks of the Mississippi River ex-
cept for the special purpose of protect
lng the alluvial lands from overflow
They have, therefore. always had sole
reference to the high-water stage, and
9he degree to which levees might pru-
IDENTIFY be relied upon to improve and
give safety to navigation, promote and
facilitate commerce, trade and the pos
tai service. has not hitherto entered
into the question of the construction
and maintenance of a levee system.
There is no doubt that the levees
exert a direct action in deepening the
channel and charging the bed of the
river during those periods of rise or
flood when, by preventing the dis
persion Of the flood waters over the
banks or through bayous and other
openings, they cause the water to rise
to higher level within the river bed
than it would attain if not thus re-
strained
1T would seem to follow that-from
the law that the volume of water flow
ing in the bed determines the size
prior to the construction of levees the
area of the mean cross-section of the
bed of the Mississippi River must have
been less than it was after the levees
had reached their most efficient condi-
ton, assuming, what is believed to be
true, that the average rainfall in the
Mississippi Valley has not materially
changed within the last hundred years.
There is some evidence in a COM
parison Of the results Of Young, Pousin
and Tuttle's examination of 1921 with
later surveys that the width of the river
has increased since that date.
There is reason to believe that during
the period when the levees We're in their
most perfect condition, from 1850 to
1858. the channel Of the river was bet
ter generally for purposes of navigation
than it has been since that time.
THE immediate effect of the levees
would be to increase the volume and
hight and accelerate the velocity of the
flood waters between them, resulting
dn an erosion and deepening of the river
bed, and ultimately in a corresponding
lowering of the flood slope, in accord
ance with the general law already
quoted that an increase in the normal
volume of discharge in a sedimentary
stream flowing through alluvial de-
posits results ultimately in a lowering
of the flood surface.
1T would seem, therefore, that
closure of the crevasses might be ex-
pected to accelerate the removal of
those Shoals which have been produced
by them, and if their closure be accom-
panied by the requisite contraction of
the channel to more nearly uniform
high-water width, a lowering of the
flood level may be expected to such an
extent as will ultimately render the
maintenance of the Ievees as an aid to
navigation practically needless above
Red River and greatly lessen the neces-
sity of their permanent maintenance for
that purpose below Red River, even at |
a reduced hight
GENIUS OF EADS.
These are the words of a majority of |
signed by Q. A. Gilmore. Lieutenant |
Colonel of Engineers and Brevet Major |
General; Charles r. Sutter, Major of |
Engineers. u. S. A; Henry Mitchell,
Coast and Geodetic Survey, and James
y. Eads and B. M. Harrod
Acknowledging the great skill and |
ability of all these gentlemen. combined
with years of study and experience,
there is yet one name attached to the |
document which will ever stand as an |
authority on water problems. It is the |
name of James b. Eads, whose untiring |
energy and great genius trained the |
waters of the Mississippi River delta |
and opened that river to the great COM |
mercial transports of the world
It was while engaged in the removal |
of the sandbars at the mouth of the |
mississippi. from 1875 to 1879, that he |
demonstrated beyond eavil or possi- |
bility of doubt the Importance of water |
control, and it is no doubt due to his |
experience. ripe as it was at that time. |
that this commission reported as it did. /
SECURING vs.. DREDGING.
We read from Corthelrs report upon |
the Mississippi jetties. in substance, |
that after the alignment Of the jetties {
had been constructed at uniform dis |
9ances apart there was not sufficient |
velocity in the new channel to remove I
the material desired to be displaced.
What steps did the engineers take to /
overcome this difficulty? Did they at
tempt to dredge it out with machinery? /
To some extent they did, but to the great /
securing ability of the water was left |
the ultimate completion of the work.
To accomplish this purpose submerged I
dams were placed across the other
channels of outlet and the surface of I
the water raised sufficient to produce /
more velocity to the water through the
Jetty channel, and this did the work.
From q depth of nine feet the channel i
was displaced to one of thirty-one feet
in period of four years.
Again, the report of this commission
reads: Any reduction of velocity by |
lessening the sustaining and transport
ing power of the water. and by arrest
ing some Of the heavier particles which |
the diminished current is unable to
move along upon the bottom, win tend I
10 cause a deposit Of solid earthly mat f
ter and raise the bed of the stream. The