Brownsville herald. [volume] (Brownsville, Tex.) 1910-current, 1928-11-15
Nv CHARLES r. STEWART

down the Mississippi valley in flood
time for the main channel Of the
Father Of Waters TO bold-even
banked up. on either side. into the
highest. strongest levees which can
be built. with a reasonable pros
pect Of maintaining them.
This figure-one-third furnished
BY Colonel Ernest Graves. Of the
war departments rivers and harbors
board. is a great deal more than g
mere estimate. It is based on care
full measurements, covering many
years.
The colonel. retired from the army
engineers. but still active in the
rivers and harbors service. j. re-
garded by the war department as
it's last word on all questions relat-
ing to the country's w-atercourses,
natural and artificial.
His verdict Is that the problem
of Mississippi flood control-to
which Major General Edgar Jadwin.
chief of army engineers; Colonel
Charles l.. Potter, president Of the
Mississippi river commission. and
Carleton w. S~turtevant. civilian ex-
pert, have been delegated by recent
act Of congress 10 find an answer
is not impossible. within certain
limitations.
That is to say. Colonel Graves
does not argue that the floods can
be dried up. He does contend that
they can be kept to areas where
they will do a minimum of damage.
IF" said the colonel, "the Missis-
sippi flowed through a groove in
the bottom az a valley and tended
to overflow that groove. there would
be no way of controlling it: but by
confirming the groove between two
l~evees. as in Diagram J."
tThe colonel sketched it.l
"And IL those levees," he CON
tinued. could not be made high and
strong enough to prevent the stream
from overlapping or breaking
through them-why, levees would be
no answer To the flood problem.
But in fact" explained the river
veteran. the Mississippi flows
through n groove in a ridge at the
bottom Of the valley. so that the
main valley consists Of two valleys.
as in Fig. 2. The river channel
%traverseS the height-of-land which
| divides them.
"lf a levee breaks. that valley is
flooded-I'm marking il "A in Fig.
3.
Most or this area ~ good land.
but there is apt to be a strip where
II is lowest that is marsis really
a secondary river bed.
Let US have n map-Fig. i-in-
stead Of a cross-section Of the coun-
try. The streams main channel ~
between the parallel. winding lines.
The shaded portions are marsh
land.
We have a spillway in the main
levee at b Fearful III a break
elsewhere. unless he relieves the
pressure on the embankment. the
engineer in charge opens the b
spillway. and a third of the stream
pours out into the marsh. which is
no great loss-it il only marsh land.
anyway.
"But the marsh is diked. too. 20
IL does not spread. II simply fol-
lows the low strips direction. be-
tween the walls Of the emergency
levee. and returns to the main
] NAttHll III ~ ~ Nf HdNNtl nkh NENAH
at the ~ spillway. maybe.
Suppose. however. there had
been no b spillway. and the levec
had broken nj 'E'-the river wouid
have flowed out. all over the land.
as far Mt any time liable 70 re trans
formed into a river bed, at certain
seasons"
But could not the main channel
be sufficiently protected ~ aroid
even the necessity for these occa-
sional diversions Of a third. per
haps. OF its volume:
Hardly" opined the colCyel.
"Such levees would have to be too
high to be dependable. Besides.
even though as the marsh. and
across the marsh. and still farther,
until rising ground stopped il.
Fig 5 illustrates how the system
should work. "F' is the secondary
channel-the relief channel. There
would not always be water in il. Of
couTse-only at high stages Of the
river. 1t might be farmed a little.
but IL must be recognized that IL 1t
was they held. here would be dan
ger Of enfiltration through the soil
under the tremendous pressure. with
the constant risk that the water
would burst out. say at &C. in Fig. 5
possibly far. far back from the
~levee.r
TO sneak Of a strip Of land on
either side Of the river as being
rescued from the flood peril is
hardly exact" supplemented the
old officer. because il is not a con-
tinuous strip. In one place there
may be an area on one side. In an
other place on the other side. de-
pending on the topography.
Roughly. 20 call il a strip. il
would average 80 miles wide by 1000
miles iong-enough to be well worth
saving
1t IS predicted that in 10 years
there will be one automobile in Eu-
rope TO every 20 people. in contrast
with the present orc machine Ia cv-