New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1896-12-20

.., nrmarily 70 afford this great city lor scores
=, vsar. 10 come adequate drainage ana 10 feiioNc
absolutely the danger OF pohulloh % Tue 49,,
.unnlv. and incidentally 10 aid IN the upou'u'''e
the c,,y's commerce and wealth Lac nio.' 49,
.s,ch,gan Canal al It's Chicago end is slightly hsher
- 49,, than the Chicago River. and as said before
~ .ha river water flowing into the~canai must De
numned n The Drainage Canal, on the o'ier n""''
~h,ch begins at Robey-st on the west ioin "a '
.ou,h branch OF tile Chicago River is oeio" inc NV
,.ve, co that the river VII! flow into II by iorce o..
~-avitv a current thus being created WHICH WI.
overcome completely the natural slight no" 'oMa4u
~. ,aLa and will cause the water or Lake Mlch'sdh
"a eovv constantly into the Chicago River ana OH o
tts new outlet, the Drainage Canal. Inc latter WIN
A,.charre It's contents into the Despiailes ni'e'
vhence through the Illinois ana the Mlssissipp' ''e
Cs,.a 90 river will finally reach the Gu! OF Mexico
tnstead OF following It's natural course 'hIous INC
great lakes and the ST, Lawrence into the Nor'h
Atlantic.
aoMp OF THE ENGINEERING PROBLEMS
The work Of cutting the great canal has been OF
.uch a nature as to require the exercise Oh inc
go, .rg,neer,ng skill. The total length OF the
canal from Chicago TO the terminus at Lockport.
III "a twenty-eght miles the line extending SOUTH
vestward from Chicago and following down the
Desplaines Valley. the course or the Ola glacier
abundant traces Of the progress or "hich are
found. The valley varies IN width from half
Iii. N a mile and through It flow the Desplanes
p,ysr and the malodorous Illinois and Michigan
Canal against both Of which the Drainage CanaI
81. had 20 be eafeguarded at various points. The
I,.sn,aines River is struggling stream. OF great
10 auc,ustine volume Sometimes Its whole dis
charge would 60 through six-inch pipe. but at
th. t,me of tho spring foods its volume Is fully
soo oo cubic feet minute and then 1t spreads over
ths whole valley. Necessarily this insubordinate
stream had to be disciplined, and the task has
baen effected by the construction OF the River d.
version Channel" This work involved the excava-
'tion of thirteen miles OF new river channel. In
,vn,ch the Desplanes Is now flowing the Drainage
Canal occupying part OF the old bed OF the river
and the building Of nineteen miles Of levee be-
tween the Main Drainage Channel and the River
Diversion Channel.
Tho River Diversion Channel Is 200 feet wide or
the bottom slopes and one half to one. and has
an average grade Of IL per 1000 feet The cost Of
the work has been about N.l0o.o0O At the head OIL
the River Diversion IS concrete DAM 1877 feet long
and at It's crest sixteen and quarter feet abov,
Chicago datum (Which Is. being Interpreted. The
low water OF Lake Michigan a certain date IL
lsI7 and 5.96l above sea-leve, a: Sandy HOOK
This dam Is known "spiway"
The Main Drainage Chanrel has been constructed
with q view to meeting the requirements Of tn,
CHICAGO OF the future. with population Of 5000 ooO
when q now Of 100000 cubic feet minute will b.
necessary; although flow Of 10000 cubic feet
minute will be ample for the needs of the presen
population, and will be the volume maintained TO
some time after the completion OF the canal From
Lockport the southern terminus. TO Willow Springs
distance Of fifteen miles, the canal Is IN the mali
cut through solid rock. Niagara limestone. North
ward from Willow Springs for q few miles the Gu