Every evening, Wilmington daily commercial., 1921-09-22

crease In either size or frcauonev. The
same thing has been found true for
tne ONO, Missouri and Connecticut
RIVERS A study of foods on the Mer-
rimac River has shown that de-
forestation of 25 per cent had no effect
on them. Studies of foode on tho
Seine and the Danube ia Europe Tor
much longer periods corrohorate these
CONCLUSIONS. I'D
The Real Cause 0f FLOODS.
The real cause Of our food disasters
Is that civilization has drawn tho
cities and homes down into the patb
Of the floods. and that we have not
given them protection. Railroads have
followed the bottoms Of valleys be-.
cause the easiest grade is there. and
the cities have beeh built down by tho
railroads instead q up on the hffs.
where more primitive men generally
built their homes and cities.
Our valley cities are sure 70 bo Do
strOyed at regular intervals until ar
Of them have been properly protected
against floods. This is the fact which
must be driven home. Floods arc ono
form Of history which may be con-
fidently relied upon 10 prove 81. Any
dweiier in an unprotected city or town
in one Of our great valleys can study
chart Of the floods that have occur
red IN the past and predict with ac-
curacy when he viii next need n row
boat or life preserver. At least. no
may predict how often he win need
IL in given period of years. soion-
lists have even made formulas for
predicting foods. ~ may BE- caiculat-
cd that floods of the greatest size On
given river viii occur. over p con-
siderable stretch Of time. once IN every
rs years on an average Those ~ fha
next magnitude VIII occur haf az
often on an average. and 30 on down.
In the diagrams which have been pre-
pared. it is remarkable how regularly
the high water marks occur.
There is no space in this article for
an adequate discussion of the methods
Of food prevention. There are two
chief methods-dikes or levees and
retaining basins. We have one of the
greatest examples Of the former in tho
jetties OF the lower Mississippi Theses
have shown the limitations o. such
works. They afford local protection,
but often serve 20 back the waters up
In other places. causing floods where
otherwise there would be none.
An excellent example of retaining
basins is seen in those on tho head ~
the Mississippi River. which we're
built primarily az aids 20 navigation.
but have had a most important uaa
in preventing floods. There are no
retaining basins in this country bullt
primarily for food control but nunaer-
Gus basins created for irrigation pup
poses. or 70 produce water power have
shown the great possibilities ~ this
method of control. In Europe retain
ing basins have been used for food
control for a long time
The best engineering opinion seems
to be that what the United States
needs is a great unified system .or
! flood control. especially for the MIS-
sissippi drainage. Most persons do
not realize what a large part ~ the
! United States this embraces. Waters
rising 70 the surface as far west as
Montana and New Mexico and az far
east as Pennsylvania and West vir-
gna ultimately reach the Mississippi
It is in this great system Of rivers that
most Of our floods occur. The Pueblo
| flood was a Mississippi Basin Hood.
Obviously food control IN this great
area must be handled as one problem.
The methods adopted in each locality
must be suited to its individual needs.
but must also take into account its
effect on the whole system. Il Is prob
able that retaining basins, many of
which viii also serve other purposes,
sucn as irrigation or power production,
will be the solution OF the problem.