The prairie land in the southwest corner of Lake Michigan, which,
seventy years ago, was half morass from the overflowing of the
sluggish creek, whose waters, during flood, spread over the low-lying,
level plain, or were supplemented in the dry season by the inflow from
the lake, showed no sign of any future development and prosperity. The
few streets of wooden houses that had been built by their handful of
isolated inhabitants seemed likely rather to decay from neglect and
desertion than to increase, and ultimately to be swept away by fire,
to make room for the extravagant and gigantic buildings that to-day
characterize American civilization and commercial prosperity. Nearly
1,000 miles from the Atlantic, a greater distance from the Gulf of
Mexico, and 2,000 miles from the Pacific, no wilder dream could have
been imagined fifty years ago than that Chicago should become a
seaport, the volume of whose business should be second only to that of
New York; that forty miles of wharves and docks lining the branches of
the river should be insufficient for the wants of her commerce, and
that none of the magnificent lake frontage could be spared to supply
the demand.
Yet this is the situation to-day, the difficulties of which must
increase many fold as years pass and business grows, unless some
changes are made by which increased accommodation can be obtained. The
nature of these changes has long engrossed the attention of the
municipality and their engineers, and necessity is forcing them from
discussion to action. As such action is likely to be taken soon, the
subject is of sufficient interest to the English reader to devote some
space to its consideration.
The most important problem, however, which the works to be
undertaken--and which must of necessity be soon commenced--will have
to solve, is not one of wharf accommodation or of increased facilities
of commerce. It is the better disposal of the sewage of the city, the
system in use at present being inadequate, and growing more and more
imperfect as the city and its population increase. During the early
days of Chicago, and indeed long after, the sewage question was
treated with primitive simplicity, and with a complete disregard of
sanitary laws.
The river and the lake in front of the city were close at hand and
convenient to receive all the discharge from the drains that flowed
into them. But this condition of things had to come to an end, for the
lake supplied the population with water, and it became too
contaminated for use. To obtain even this temporary relief involved
much of the ground level of the city being raised to a height of 14
ft. above low water, a great undertaking carried out a number of years
ago. To obtain an adequate supply of pure water, Mr. E.S. Chesborough,
the city engineer, adopted the ingenious plan of driving a long tunnel
beneath the bed of the lake, connected at the outer end to an inlet
tower built in the water, and on shore to pumping engines. This plan
proved so successful that it is now being repeated on a larger scale,
and with a much longer tunnel, to meet the increased demands of the
large population.
But to improve the sanitary condition of the city has been a much more
difficult undertaking, as may be gathered from the following extract
from an official report: "The present sanitary condition calls loudly
for relief. The pollution of the Desplaines and the Illinois Rivers
extends 81 miles, as far as the mouth of the Fox (see plan, Fig. 1) in
summer low water, and occasionally to Peoria (158 miles) in winter.
Outside of the direct circulation the river harbor is indescribable.
The spewing of the harbor contents into the lake, the sewers
constantly discharging therein, clouds the source of water supply (the
lake) with contamination. Relief to Chicago and equity to her
neighbors is a necessity of the early future." To make this quotation
clear it is necessary to explain the actual condition of the Chicago
sewage question.
Long before the present metropolis had arrived at the title and
dignity of a city, the advantage to be derived from a waterway between
Lake Michigan and the Illinois River, and thence to the Mississippi,
was well understood. The scheme was, in fact, considered of sufficient
importance to call for legislation as early as 1822, in which year an
act was passed authorizing the construction of a canal having this
object. It was not commenced, however, till 1836, and was opened to
navigation in the spring of 1848. This canal extended from Chicago to
La Salle, a distance of 97¼ miles, and it had a fall of 146 ft. to low
water in the Illinois River (see Fig. 1). It was only a small affair,
6 ft. deep, and 60 ft. wide on the surface; the locks were 110 ft.
long and 18 ft. wide. The summit level, which was only 8 ft. above the
lake, was 21 miles in length. This limited waterway remained in use
for a number of years, until, in fact, the growth of Chicago rendered
it impossible to allow the sewage to flow any longer into the lake. In
1865 the State of Illinois sanctioned widening and lowering the canal
so that it should flow by gravity from Lake Michigan. The enlargement
was completed in 1871, by the city of Chicago, and the sewage was then
discharged toward the Illinois River. But the flow was insufficient,
and in 1881 the State called on the city to supplement the flow by
pumping water into the canal.
[Illustration: FIG. 1]
In 1884, engines delivering 60,000 gallons a minute were set to work
and remedied the evil for a time, so far as the city of Chicago was
concerned, but the large discharge of sewage through the sluggish
current of the canal and into the Illinois River proved a serious and
ever-increasing nuisance to the inhabitants in the adjoining
districts. To enlarge the existing canal, increase the volume and
speed of its discharge, and to alter the levels, so that there shall
be a relatively rapid stream flowing at all times from Lake Michigan,
appears the only practical means of affording relief to the city, and
immunity to other towns and villages lying along the route of the
stream.
The physical nature of the country is well suited for carrying out
such a project on a scale far larger than that required for sewage
purposes, and works thus carried out would, to a small extent, restore
the old water _regime_ in this part of the continent. Before the vast
surface changes produced during the last glacial period, three of the
great lakes--Michigan, Huron and Superior--discharged their waters
southward into the Gulf of Mexico by a broad river. The accumulation
of glacial debris changed all this; the southern outlet was cut off,
and a new one to the north was opened near where Detroit stands,
making a channel to Lake Erie, which then became the outlet for the
whole chain by way of Niagara. A very slight change in levels would
serve to restore the present _regime_. Around Lake Michigan the land
has been slightly raised, the summit above mean water level being only
about 8 ft. Thirty miles from the south shore the lake level is again
reached at a point near Lockport (see Fig. 2); the fall then becomes
more marked. At Lake Joliet, 10 miles further, the fall is 77 ft.; and
at La Salle, 100 miles from Chicago, the total fall reaches 146 feet.
At La Salle the Illinois River is met, and this stream, after a course
of 225 miles, enters the Missouri. In the whole distance the Illinois
River has a fall of 29 ft. "It has a sluggish current; an oozy bed and
bars, formed chiefly by tributaries, with natural depths of 2 ft. to 4
ft.; banks half way to high waters, and low bottoms, one to six miles
wide, bounded by terraces, overflowed during high water from 4 ft. to
12 ft. deep, and intersected in dry seasons by lake, bayou, lagoon,
and marsh, the wreck of a mighty past."
The rectification of the Illinois and the construction of a large
canal from La Salle to Lake Michigan are, therefore, all that is
necessary to open a waterway to the Gulf of Mexico, and to make
Chicago doubly a port; on the one hand, for the enormous lake traffic
now existing; on the other, for the trade that would be created in
both directions, northward to Lake Michigan, and southward to the
Gulf.
As a matter of fact this great scheme has long occupied the attention
of the United States government. A bill in 1882 authorized surveys for
"a canal from a point on the Illinois River, at or near the town of
Hennepin, by the most practical route to the Mississippi River ... and
a survey of the Illinois and Michigan Canal connecting the Illinois
River with Chicago, and estimates from its enlargements." This scheme
only contemplated navigation for boats up to 600 tons. In 1885 the
Citizens' Association, of Chicago caused a report to be made for an
extended plan. The name of Mr. L.E. Cooly, at that time municipal
sanitary engineer, was closely associated with this report, as it is
at the present time for the agitation for carrying out the works. This
report recommended that "an ample channel be created from Chicago to
the Illinois River, sufficient to carry away in a diluted state the
sewage of a large population. That this channel may be enlarged by the
State or national government to any requirement of navigation or water
supply for the whole river, creating incidentally a great water power
in the Desplaines valley." Following this report and that of a
Drainage and Water Supply Commission, a bill was introduced into
Congress supporting the recommendations that had been made, and
providing the financial machinery for carrying it into execution.
Since that date much discussion has taken place, and some little
action; meanwhile the sanitary requirements of the city are growing
more urgent, and the pressure created from this cause will enforce
some decision before long. Whether the new waterway is to be
practically an open sewer or a ship canal remains yet to be seen, but
it is tolerably certain that its dimensions and volume of water must
approximate to the latter, if the large populations of other towns are
to be satisfied. In fact the actual necessities are so great as
regards sectional area of canal and flow of water--at least 600,000
ft. a minute--that comparatively small extra outlay would be needed
to complete the ship canal.
[Illustration: FIG. 2]
The attention of engineers in Chicago, as well as of the United States
government, is consequently closely directed at the present time to
such a solution of the problem as shall secure to Chicago such a
waterway as will dispose of the sewage question for very many years to
come; that shall relieve the inhabitants on the line of the canal from
all nuisances arising from the sewage disposal, and shall provide a
navigable channel for vessels of deep draught. The maps, Figs. 1 and
2, give an idea of the most favored scheme--that of Mr. Cooley.
As will be seen, the canal commencing near the mouth of the Chicago
River passes through a cut in the low ridge forming the summit level;
then it runs to Lake Joliet, and through the valleys of the Desplaines
and Illinois Rivers, to the Mississippi at Grafton, a distance of 325
miles. The elevations and distances of the principal points are as
follows:
------------------------------+------------+-----------+-----------+
| | | |
| | Low Water | |
| Miles from |Level below| High Water|
| Lake | Chicago | above Low |
| Michigan. | Datum. | Water. |
| | | |
------------------------------+------------+-----------+-----------+
| | | |
| | ft. | ft. |
Lake Michigan | | | 4.7 |
Lake Joliet | 40 | 77 | 5 to 6 |
Kankakee River | 51.30 | 93.70 | 18 to 20 |
Morris | 61 | 100.3 | 21 |
Marseilles | 77 | 102.8 | 4 to 5 |
Ottawa | 84.5 | 132.1 | 26 |
La Salle | 100.3 | 146.6 | 28 |
Hennepin | 115.8 | 148.7 | 25 |
Peoria | 161.4 | 151.3 | 21 |
Mouth of the Illinois | 325 | 172.4 | 20 |
| | | |
------------------------------+------------+-----------+-----------+
The project in contemplation provides that the depth of the canal as
far as Lake Joliet (which is about six miles long) shall be not less
than 22 ft., and on to La Salle not less than 14 ft. at first, with
facilities to increase it to 22 ft. Beyond La Salle to the mouth of
the Illinois, dredging and flushing by the large volume of water
pouring in from Lake Michigan would make and maintain ultimately a
similar depth.
As it appears recognized that the sewage channel of Chicago must be 15
ft. deep, and as provision is now being made all over the great lake
system for vessels drawing 20 ft. of water, a comparatively small
additional outlay would provide for a channel available for the
largest lake vessels. It is claimed that by the co-operation of the
Chicago municipality and the general government--the latter to advance
a sum of not less than $50,000,000--a ship (and sanitary) canal 22 ft.
deep could be made from the lake to Joliet, extended thence to Utica,
20 ft. deep, and from there to the Mississippi, 14 ft. deep.
That such a work would vastly enhance the commerce, not only of
Chicago, but of the whole section of the country through which the
canal would pass, admits of but little doubt, and probably the outlay
would be justified by results similar to those achieved with other
great canal works and rectified rivers in the United States.
The following figures, showing the tonnage carried in 1888-89, give
some idea of the volumes of water-borne traffic in America:
Tons.
Detroit River 19,099,060
Erie Canal 5,370,369
Sault Ste. Marie 7,516,022
Welland Canal 828,271
St. Lawrence Canal 1,500,096
Mississippi to New Orleans 3,177,000
" below St. Louis 845,000
Ohio 2,236,917
Chicago Canal and lake 11,029,575
Except on the Mississippi, it may be reckoned that navigation is
closed by ice during five months a year. It may be mentioned, by way
of comparison, that the traffic on the Suez Canal during the year
1888-89 was 6,640,834 tons.
One very interesting point in connection with this work is the effect
that the diversion of so large a body of water from the lakes will
have upon their _regime_. At least 10,000 cubic feet a second would be
taken from Lake Michigan and find its way into the Mississippi; this
is approximately 4½ per cent. of the total amount that now passes
through the St. Clair River and thence over Niagara.
The following table gives some particulars of the great lakes and the
discharge from them:
---------------+----------+-------+--------+-----------------------
| | | |Cubic Feet per Second.
|Elevation |Area of| Area of+-------+-------+-------
| above | Basin,| Lake, | | |
Lake. |Mean Tide.| Square| Square| Rain- |Evapo- | Dis-
| Feet. | Miles.| Miles.| fall. |ration.|charge.
| | | | | |
---------------+----------+-------+--------+-------+-------+-------
| | | | | |
Superior | 601.78 | 90,505| 38,875 |187,386| 34,495| 80,870
Huron and Mich.| 581.28 |121,941| 50,400 |262,964| 66,754|216,435
Erie | 572.86 | 40,298| 10,000 | 96,654| 13,870|235,578
Ontario | 246.61 | 31,558| 7,220 | 75,692| 10,568|272,095
| | | | | |
---------------+----------+-------+--------+-------+-------+-------
The average variation in level of the lakes is from 18 in. to 24 in.
during the year, and the range in evaporation from year to year is
also very considerable; thus the evaporation per second on Huron and
Michigan, as given in the table above, is nearly 67,000 ft., but the
figures for another year show nearly 89,000 ft. per second, which
would represent a difference of 6½ in. in water level. As a discharge
of 10,000 cubic feet a second into the new canal would lower the level
of these two lakes by 2.87 in. in a year, it follows that the
difference between a year of maximum and one of minimum evaporation is
more than twice as great as would be required for the canal, and even
under the most unfavorable conditions the volume taken from the whole
chain of lakes would not lower them an inch.
When the variations in level due to different causes--rain, wind, and
evaporation being the chief--are taken into consideration, the effect
of 10,000 cubic feet a second abstracted would probably not be
noticeable. That this would be so is the opinion, after careful
investigation, of many eminent American engineers. On the other hand
there is a similar unanimity of opinion as to the advantages that
would be obtained in the condition of the Mississippi by adding to it
a tributary of such importance as the proposed canal.--_Engineering_.
* * * * *