CHICAGO AS A SEAPORT.
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.
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.
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:
| Miles from Lake Michigan. | Low Water Level below Chicago Datum. | High Water above Low 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 |
| Mississippi 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 | ||||||
| Lake. | Elevation above Mean Tide. | Area of Basin, Square Miles. | Area of Lake, Square Miles. | Rainfall. | Evaporation | Discharge. |
| 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.