, 1881-07-10
THE CANAL pUMPIMG-WDRYS.

The bids have been opcncal for furnishing
the new pumping-worl1s wflicl, are to be 10
Gated at or hear Bridgeport for the PURPOSE
of supplying the canal with sufficient watcl
to carry of the drainage 3f both branches OF
the Chicago River. These bids range FROM
SILT, $40 to S:00, ,000 They are apparently OIL
about the same plane, and tile variance IN
cost is regulated by the actual power which
it is proposed to furnish. 1t will be fur the
City Engineer to tle .ernine whether the
engines OF lesser cost aml relatively less
power have the capaeify to do the work re-
quircl-viz.: the raising Of Go,0o0 cubic
feet Of water per minu tc at a hight Of eight
feet, or 10 the bids really mean to raise 40,
9Oo cubic feet of water eight feet above the
present level of the wabcr IN the canal? The
canal now flows, say about 10000 cubic feet
minute OH depth Of about five feet Mt the
s|,allowest places. The proposition, rs we
understand it, is to add Il maximum OF eight
feet in depth to the present depth, which will
increase the present flow by 10000 cubic rect
per minute, 1nakinga total Of 00,000. Which,
ever Of the bids shall be accepted, it is now
certain that the entire cost Ct the new works.
including the she'd and all accessories. will
cOlle within S25O, ,000,-a mere bagatcl in
comparison with the benefits to Chicago and
the towns along the line Of the canal and
river which may be reasonably expected
from the vastly increased volume and flow Of
water.
The requirement from the pumps is that
the water in the canal at tho point where the
works may be located shall be raised eight
feet higher than the present canal-leyel.
This Increased depth cannot fail to produce
the desired results. The greatest complaints
of the iilsutticiency of the canal in its pres
cnt condition to carry off the sewage come
in tile winter. The water with 4 depth Of
about five feet, two of which were frozen at
the top i'll solid ice last winter, has a 1lecessa-
rily sluggish movement. But il eight feet
be added to this depth at this end, there will
be eleven feet Ut water under the ice instead
of three feet, as was the case last winter, and
the fall will be strong and rapid.
It is not probable that it will be necessary
to keep the pumps'a at work constantly nor to
their full capacity. At times a supply of
half the quantity Of water which the pumps
will be able to raise will be sufficient, and
them at all. In this respect the experience
will probably be much the same as ut the
Fullerton avenue works, constructed for
the benefit of the North Branch. There are
times in the spring floods when the water in
the canal flows into. the river and thence
into the lake.
This expenditure of a quarter Of a million
dollars will nrac;ipalfv accnn,nIiah all fhn ra~
suits for many years to come which the fur
ther widening and deepening Of the canal
would achieve. To enlarge the canal bv
widening and deepening to secure dis
charge Of 6o,00o cubic feet per mill
ute would probably cost from six to
eight millions of dollars. The price
Of the land which it would be neces-
sary to purchase along the line of the canal
TO hold the present accumulation of dirt
from the first deepening, as well as the in,-
mense new excavations would probably ex-
ceed the entire cost of the protected pump