The Topeka state journal. [volume] (Topeka, Kansas) 1892-1980, 1900-01-02


uTne through the Chicago river to the
canal is entirely controlled by the bear
trap dam and controlling works situa-
ted at the Lockport terminal, the fall
south of the controlling works being
abrupt and about 40 feet in the next
miles. 1t is by means of these eontroll-
ing works that the water was turned
down the valley by the simple opening
of the great gates or valves and it is
also by means of the controlling works
that the waters down the valley can be
as suddenly turned off in case emergen-
cies might demand.
Therefore the popular belief that the
waters of the canal, having been once
turned down the valley the flow must
be uneeasing and beyond human con-
troll is erroneous for the flow of this
great volume of 100000 cubic feet per
minute can be stopped almost as easily
as the simple turning of a faucet in the
SpigOt of a barrel The controlling
works have involved the construction of
seven sluice gates of metal, with the
necessary bulkheads, and one bear trap
dam. The sluice gates have vertical
flow of 20 feet and an opening of 80 feet.
The bear-trap dam has an opening of
$50 feet and an oscillation of II feet
vertically. This dam is essentially two
great metal leaves, hinged together, and
working between manSonry bulkheadS.
The downstream leaf is securely hinged
to a very heavy foundation, and the
upstream leaf is so placed as to present
the barrier to the water. This structure
is operated by admitting water through
properly constructed conducts, controll-
ed by valves beneath the leaves just
described. To raise the crest of the dam
water is admitted from the upstream
side and the discharge shut off until the
resired height is obtained, and then the
valves are adjusted so that the volume
of water beneath the leaves shall be
constant. To lower the crest the water
beneath the leaves to drawn off until
n fairr h iC 6xa1 hCV1 t1l
valves are again arranged so as to
maintain a constant volume of water.
The first work in this great enterprise
was begun on shovel day." September
3, 1892, on the rock cut below Lemont,
on the line between Cook and Will coun-
ties so that little over seven years
have been consumed in the entire work
involving an outlay of about $33, 600, 900.
over so per cent of the entire work
was done during the so-called panic
period and, owing to this fact, the en-
tire cost of construction was reduced
about IS 600, 600. Indeed, the board of
trustees and its engineers are unan-
imous in the belief that the work could
not now be duplicated under existing
prices for both labor and material for
less than $40,000,0O
Up to the present time and, indeed,
for the past Is years, the entire sew
age of the city of Chicago which empties
into the Chicago river has, as a matter
of fact, been flowing down the Des-
PLANES valley and into the ILLINOIS ana
Mississippi rivers.
That dozens of the Mississippi valley
towns are ignorant of this fact-as 80
per cent of them certainly are-makeS
it none the less a fact; and Furthermore,
all this time this sewage has been in
a highly offensive condition for it has
passed down the Illinois and Michigan
canal, into which it was dumped by the
Bridgeport pumping works from the
south fork of the south branch in
OH Of r71lx- hoT hi foot
per minute 1t is this same flow of act
ual sewage therefore, and no more and
no less, that is to pass down the Illinois
valley but diluted by a. tremendous
flow of water from Lake Michigan in
creasing the total volume to 300, 900
cubic feet per minute, or nearly eight
times the past flow; and, by the rapid
process of oxidation that takes place
in surging and flowing water this sew
age will be rendered innocuous and
harmless even before the city of Joliet
is reached, if the contention of the
most eminent chemists and bacteriolog-
lists is correct.
Later on, say in six or seven months,
when the system of intercepting sewers
now in process of construction, by the
city of Chicago is completed, an ap
proximate of $4,000 cubic feet per min
ute of sewage, which is now flowing in
to Lake Michigan, will be diverted into
the Chicago river and the canal so as
to increase the addition of 5000 feet
per minute OF sewage the amount now
going down the Illinois river
Consequently it is said. it will be several
months after the opening of the canal be-
fore any one can complain of receiving
a single ounce of Chicago sewage addi-
tional to what has for years been flowing
down the valley; and, reduced to a plain
statement of facts, according to one Of
the trustees the only complaint which
the valley towns can now make against
the opening of the canal is that it will
Immediately benefit their present condi-
tons by a water dilution Of seven and
one-half times the volume of sewage now
diverted down the valley.
The canal has been constructed in strict
conformity with the requirements of the
law under which the sanitary district of
Chicago was organized and it is of suffic-
maintain at all times a continuous flow
of at least 300. 900 cubic feet of water per
minute, with a current not exceeding one
mile per hour. The flow of water is of
sections of the canal, and the same depth
throughout the rock sections. The rock
sections are constructed of a width of
160 feet at the bottom. All of the rock
sections and five of the earth sections
have now a capacity for flow of 500. 900
cubic feet of water per minute, so that
when the population of the city of Chi
cagO increases to :. 600. 900 people these sec
tions will still be adequate for all de-
mands: consequently the only work then
remaining to be done to fulfil the
the increasing population will be the
mere work Of shoveling and dredging to
deepen and widen eight miles of the
earth sections to conform to the rock
sections.
The plan of the Chicago canal can hard
" be said to have been original with any
one man. It has been a growth, a de-
velopment, and many men can justly lay
great public work.