, 1875-03-07

THE DANGER OF FLOOD IN CHICAGO
The apprehensions of food in this city in
case of sudden thaw and heavy rims are cer-
tainly warranted by the experience Of 1849
under very similar conditions. The food Of
that year occurred March u, and not in
April, as has been enormously stated Any
preparations that may be made to meet the
possible disaster should not, therefore, be de-
layed. Indeed, the early agitation Of the
danger in the columns Of TIE TRIBUNE has
already induced the dock-owuers and the
wholesale merchants to take every individual
precauion in their power; easements are
| very generally cleared Of goods, and ware
house employees have standing notification to
be on hand at any sudden rainfall The
Board Of Public Works are also on the alert,
and ought to be prepared with prompt and
efficient means for breaking away any ice
gorge that forms Of such size and character
as to threaten danger.
If a flood comes this year, it Will come as
it did twenty-si1 years ago, and from the
same source. The seat Of the danger is the
Aux PLANES River near Summit It was an
ice-gorge which formed in this river about
half mile west Of Summit that caused the
flood of 1649. The usual channel Of the
river was thus cut of, torrent Of water
overAowed its eastern banks, and found IN
easy outlet over large swale located north
east Of Summit The waters spread out over
the low land between the Aux Plaines
and the city, and found channel in the
South Branch, thence rushing down into
the main channel Of the river, carrying away
docks, shipping goods, bridges, etc. There are
certain circumstances now which render IN
overflow Of the Aux PLANES River more dan
gerous than formerly. The first of these is
the excavation known as the Ogden Ditch,
which is connected with the very swale which
furnished the principal outlet for the flood Of
1s49 The Ogden Ditch furnishes direct
connection with the South Branch, and would
supply natural channel for an overflow of
considerable water from the Aux PLANES at
any time its own channel is closed anywhere
southwest Of Summit. There is fall
of full feet between this swao md
the city limits, distance of about
four miles, and the Ogden Ditch would
carry la=ge body of water at tearing rate
into the South Brunch Another circum-
stance which would probably contribute to
the danger is to be found IN an island formed
by DETECTION in the river to the north Of
Summit The channel at the east side Of this
island has been damned up at both ends by |
the owners Of the adjoining property, wheth- |
er rightfu1ly or not This cuts off one Of the |
natural channels Of the river, and to that e1-
tent increases the strain upon the other chan- |
mel in case Of torrent or large bodies Of |
doating ice.
The Illinois i Michigan Canal, which |
runs parallel with the Aux Plaines River, will +
not help much to carry of the surplus water. |
It will be remembered that the canal
was deepened for the purpose Of changing
the current Of the Chicago River, and to
make it empty into the Illinois River through
the canal, instead Of into the lake; but the
fall in the. bottom Of the new canal is only
feet II. so miles from Bridgeport to Lockport.
Now, the surface ct the water in the new
:anl is below the bottom of the old canal,
md thus the new canal acts practically as a
1rain for the land along its line. It has been
noticed by the inhabitants living along the
ANAL that, in spring time and in time of
leavy rains, SO much water runs into the new
anal by underground channels from the land
N both sides, but especially from the Aux
'laines side, that its force overoomes the fall
t 8 feet in 80 miles, and the water turns the
urrent back into the Chicago River. In case
here were food from the Aux PLANES, the
elief from the canal in carrying off the over
ow would not amount to much, for the rea-
ons here named
As an offset to these additional sources, |
'hich did not exist in 1s49, it must be re-
rendered that the grade Of Chicago has been
Used from to 10 feet higher than it was at
lat time; that the river has been deepened
.at the bridges and docks are higher and
ore substantial; and that there is practically ,
much larger, broader, and. deeper channel ]
II any flood in the Chicago River to pass of :
to the lake.. There are but two or three
Iings which the Board Of Public Works can
D: The first is to be in readiness to break {
ray any iee-gorge at the mouth Of the Chi a
'go River: and likewise any ioe-gorge that q
AZ forn :in'- the Aux PLANES River | =
thin q. mile either north or west
Summit The latter is more im- +
'rtant than the former, since the ice- il
'rge in the Aux PLANES would be the s
sztins-point Of the flood It may also be q
acticahle and worth while to construct an t
nbanknent across the Ogden Ditch where Q
joins the swale Of the Aux Plaines River to q
9 northeast of Summit, thus barricaling il
q natural channel which a torrent would y