The Forest Republican. [volume] (Tionesta, Pa.) 1869-1952, 1892-08-24
THE MISSISSlPPrS FLOOD.
WHAT CAUSES THE GREAT RIV.
ERs ANNUAL OVERFLOW.
Rivers and Bayous Have Built Up
Ridges on Which They FIow-In-
undating the Bottom Lands.

Rivers and Bayous Have Built Up
Ridges on Which They FIow-In-
undating the Bottom Lands.
II VERY spring the Mississippi Riv-
- er, swollen by the melting of
the snow in the Rocky Noun
tains and by the abundant
spring rains, threatens with inundation
the low lands of Mississippi and Louisi-
ana. Not infrequent it breaks through
the bonds which confine its course and
spreads its muddy waters over thousands
of square miles of that fertile region,
destroying the helds of young cotton and
cane, and burying the fertile soil be-
meath layers of river mud.
Those who read accounts of these in.
undations, of their widespread destruc-
tion and of the immense areas covered
by them, may be at a loss to understand
how the mere fact of this river overflow
ing its banks can lead to such extensive
floods.
These bottom lands are a peculiar re-
glon. Originally a shallow arm of the
gulf, they have been filled by deposits
u
tenths of the region is marsh covered
with grass or cypress forest, through
which flows the Mississippi with its
branches, and which are intersected
by countless bayous, forming an intri.
cate network of water courses. All the
streams, with scarcely an exception, flow
upon the tops of ridges. These rides
are low, rising but ten to twenty feet
above the intervening ares Of marsh, aud
range in breadth from few rods up to
perhaps four miles. The stream bed is
in a notch upon the summit.
These ridges have been built by the
streams. In former times, before the
streams were confined to their beds by
levees, they overilowed their banks with
every high "tide," as the flood Is called.
The river, always muddy, is in time of
flood heavily charged with sediment,
brought perhaps from the high plains
and the Rocky Mountains. Where the
stream is rapid it has no difficulty in
bearing onward its load OF sediment, but,
when its velocity is checked, as 1t is
when the stream is suddenly broadened, =,
it is forced to deposit some of it, When
the stream overiows its banks it be-
comes thus broadened, its velocity is
checked, and it consequently deposits
some of its load, the coarsest material
first, the finer material later. By this
process of overflow have the rivers and
bayous built up the ridges on which they
flow.
The only habitable and tillable parts
of this region are the gentle slopes of
these river ridges, aud upon these, which
form but triaing proportion of the en-
tire area, the inhabitants are congre-
gated. The roads commonly follow the
river, running Immediately at the foot
of the levee, and it is along these roads
that the houses are found. The planta-
tions stretch in narrow strips back from
the river.
The levees, which are built continu-
ously along both sides of the river and
principal bayous of this region, are
sometimes ten or twelve feet in height,
and in time of flood the river is frc-
quently full up to the top OF the levee
One may ride along the road under the
levee with the water of the river five or
six feet above his head.
When the river is in food the levees
are patroled night and day by the in
habitants, watching for the slightest in.
dlcation of weakness. A thin stream Of
water the size Of ope's finger breaking
through the lower part of the leveo may
in an hour, if unchecked develop into u
break or crevasse which can not be closed,
and which may involve II loss of millions
of dollars to the neighboring country.
Such breaks ms often caused by the bur
rowing of animals. or more frequently by
rice fumes or openings through the
levees for the purpose of letting water
into the rice fields.
Scarcely spring passes that such ere
vases do not occur from such trihing
origin. The levee, once broken, the
waters pour through, rapidly widening
the breach, and rush down the slope of
the river ridge directly away from the
river, On reaching the swamp, the cur
rent is broken and diverted and the
waters, spreading up aud down stream,
gradually rise back toward the Ievees on
either side. They pour also through the
swamp, and extend to the ridges of
neighboring streams, flooding the cult
yated lands upon them. Thus it is easy
to see that, since the whole country lies
below the level Of the river, if way is
once opened for the water into the couu-
try, it may spread indefinitely aud involve
widespread ruin and destruction. -Cour-