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3d Session.

No. 50.

LETTER

THE SECRETARY OF WAR,

COMMUNICATING

A report of the Chief of Engineers upon the proposed improvement of the

Mississippi River from Alton to the mouth of the Varamee Rirer.

MARCH 2, 1871.-Ordered to lie on the table and be printeil.

WAR DEPARTMENT, Jarch 2, 1871. The Secretary of War has the honor to submit to the Senate of the United States the accompanying report of the Chief of Engineers upon the proposed improvement of the Mississippi River from Alton to the mouth of the Maramec River, and including the harbor of St. Louis, the survey for the improvement having been undertaken in pursuance of the requirements of the act of Congress of July 11, 1870.

WM. W. BELKNAP,

Secretary of War.

OFFICE OF THE CHIEF OF ENGINEERS,

Washington, D. C., March 1, 1871. SIR: I have the honor to transmit herewith the report of Lieutenant Colonel W. F. Raynolds upon the survey and examination of the Missis sippi River from Alton, Illinois, to the mouth of the Maramec River, including the harbor of St. Louis, made in compliance with the requirements of the second section of the act of July 11, 1870, making appropriations for certain public works.

This survey and examination, owing to the limited time and funds at command, was necessarily incomplete. To reach a satisfactory conclusion as to the plan for, and cost of, securing a permanently improved condition of the Mississippi River within the limits named, requires the thorough, systematic survey recommended by Lieutenant Colonel Raynolds and his assistant, Captain Allen.

The recommendations of Colonel Raynolds to improve the harbor at Alton by closing the channel west of Ellis Island, opposite Alton, by et cheaply constructed dam; to diminish the abrasion of the river banks opposite the mouth of the Missouri River, by clearing Mobile Chute and the slough west of Maple Island of snags and other obstructions to the free flow of water, and to diminish the scour in Sawyer's Bend by clear. ing Pocket Chute of similar obstructions, are all concurred in.

The reopening of Cabaret Slough is desirable, but until the detailed survey recommended is made, no proper project for this or for other works, except those named above, can be prepared.

The following estimate for operations during the next season is sub mitted by Colonel Raynolds. The appropriation of that amount is recommended : For Alton harbor

$15,000 For mouth of the Missouri.. For a general survey

23,000

27,000

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There was appropriated for the improvement of the Mississippi River in the vicinity of St. Louis in 1836, $15,000; in 1837, $35,000 ; and in 1811, $25,000; in all, $75,000; and it appears from a statement in a fr port to the city council of St. Louis in 1869 that the city had expende for various works for the improvement of the barbor, up to that date, $810,121. Very respectfully, your obedient servant,

A. A. IIUMPIREYS,

Brigadier General and Chief of Engineers. Ilon. W. W. BELKNAP,

Secretary of War

OFFICE WESTERN RIVER LYPROVEMENTS,

St. Louis, Missouri, February 17, 1871. GENERAL: I have the lionor to forward herewith the report of Captain C. J. Allen of a survey at Alton and St. Louis harbors, Mississip River, between Alton and the month of Maramec River," made undu my direction.

As I have been in daily communication with Captain Allen durin: the progress of this survey and the preparation of his report, and we bare made it a matter of frequent discussion, our views have been brought so nearly in accord as to render it umecessary for me to do more than to forward the report with my approval.

I am satisfied that in dealing with a stream of the size and the peu liar characteristics of the Mississippi, the only safe method of proceeding is to follow nature as closely as practicable : when we find the river in clined to do what we would like to have done, to aid it by all the means at our command; when the contrary is the case, to interpose obstruc tions as speedily as practicable, and do the least that will ettect the objeti in view.

In the case of the Alton harbor, the desire is to get as much deep water in front of the city as practicable. The most natural method of effecting this object is to close the channel west of Ellis Island. A com parison of the map survey, in 1868, made under the direction of H.C. Long, esq., civil engineer, with the map of the present survey, indicates that this process has already commenced, though the data on map of 1868 is too meager to show exactly what change was taken place. li this passage could be closed at low water only, all that is required would be effected. The low and comparatively cheap dam proposed by ('ap tain Allen would probably be all that would be required.

If a greater proportion of water passed to the westward of Maple Island, the tendency would be to lessen the effect of the scour on the east bank, opposite the mouth of the Missouri. This passage is now

obstructed by snags; hence, if our principles are correct, they should be removed.

Before this survey was commenceri, I visiter the mouth of the Missonui and made a personal examination of the state of affairs in that locality. The scour of the bank immediately opposite the junction of the streams is still going on rapidly; the rate, of course, varying with the relative stages of the rivers. If the Missouri is low when the Mississippi is high, the action is little or nothing. I visited the head of Mobile. Chute, and found a considerable quantity of water making its way through the piles of logs and drift-wood, obstructing that passage. The map accompanying the report of 18 13 shows this passage as the main channel of the Missowi in 1529. The thought at once suggests itself, why not restore the condition of attairs that then existed? The work can be alone by one of our snag-boats in about two months. Its execution would be legitimate under the general appropriation for the improvement of these rivers, for, aside from any effect which we might hope for elsewhere, all boats navigating the Missouri would use this }vassage if it were open.

The tree passage of the water through this channel would have an eftirt opposite the present mouth of the Missouri River similar to lovering the water in that stream, and consequently to diminish the scour where it is now most rapid and dangerous, and, taken in connection with the removal of the obstructions west of Maple Island, we would have reason to hope for a result by which the dangerous action now going on woull be eftectually checkel. In short, the changes proprosed seem to me only restoring the coulition of affairs as they existed forty years ago, and are, to my mind, so obvious, that I propose, in case a sutticient appropriation is made, to put the snag-boats in commission the coming season to remove these obstructious, without asking for a special appropriation.

The dike and the Grand Chain have failed entirely to detleet the river or any portion of it into Cabaret Slough, or to any appreciable degree clininished the scour in Sawyer's Bend.

In 1813, the water in Cabaret Slough was from six to nine feet in (lepth. At present, the slough is filled with sand to from four to eight feet above the level of low water, and, of course, no water passes through it at that stage. The change in the regimen of the river in this locality since the Grand Chain dike was proposed is so marked and radical as to almost lead to the conclusion that the effect of the dike has been directly the reverse of that which was expected; but we have no data to show the condition of the head of the slough previous to the building of the dikes, nor do we yet know fully what may be there; no borings have ever been made to determine the position of the bed of rock or any other obstruction which may effectnally prevent the washing out of this channel. We know that in the Pocket Chute, and above it on that side of the river there are, at present, a large number of snags visible; as to how many there are that are invisible, we are ignorant. These snags are not in the channel, hence are not obstructions to the navigation; and, as the snag-boats have had more than they could ilo to keep the channel clear, no work has ever been done in this locality. There is, of course, it possibility that during some high stage of the river ('abaret Slough may again be washed out; but if we could increase the volume of water passing through Pocket Chute, the scour in Sawyer's Bend would evidently be diminished. The conclusion is that the snags in that locality should be removed. I therefore regard Pocket Chute and the east side of the river above it, as far as the

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head of Cabaret Slough, as one of the most important localities in which our suag-boats could work. But with our limited means, not having enough boats to keep the channel clear, even if kept at work all the time, and the appropriation not being sutlicient to keep the boats in commission throughout the year, I hesitate to employ the means at command, except to improve the main channels.

Every day's study of the duty under my charge increases my sense of the important service which may be rendered by the snag-boats, if the means are provided to render them as efficient as practicable.

Aside from the good which can be done by keeping the channel free from snags, I am satisfied that they could do much to remedy the evils which have so long been at work, and which are still threatening the important interests at St. Louis, Alton, and vicinity; but they have never worked a day for the direct purpose of doing so. This portion of the river has been treated like every other portion, all labor being contined to the removal of the worst obstructions from the channel, and thus render all the aid in our power to the general commerce of the river. But

where important interests demand that the quantity of water flowing through passages not used for commerce should be increased. The removal of the snags in these passages would certainly help to effect that object, and might be all that was required. It seems to me useless to argue further the propriety of furnishing the means to keep these boats constantly at work.

The necessity of a more careful examination of the river, to include a minute survey from bluff to bluff, and borings to determine the posi tion of the rock in all places where improvements are proposed, is še obvious that I am surprised that nothing of the kind has been done. Nearly a inillion of dollars has been expended by the General Govern ment and city authorities of St. Louis on “improrements" in St. Louis harbor; and yet, with the exception of those of the bridge and waterworks, we do not know that any borings have been made. Dikes have been built which have entirely disappeared. Stone has been thrown into the river without the least idea of the amount which would be required to effect the object in view. No general system of improvement has ever been adhered to. Every engineer has done what “ seemed good in his own eyes,” and all, it would seem, for the very simple rea son that no one knew what effect the work he proposed or had under taken would produce. I indorse most heartily Captain Allen's reconmendation of an appropriation for a thorough examination of this section of the river. Very respectfully,

W. F. RAYNOLDS, Lieutenant Colonel Corps of Engineers, t. s. d. Brigadier General A. A. HUMPHREYS,

Chief of Engineers, U. S. A., Washington, D. ('.

ST. LOUIS, MISSOURI, February 3, 1871. COLONEL: I have the honor to submit herewith my report of the survey and exam ination of the Mississippi River from Alton, Illinois, to the month of the Maraipe River, in Missouri. Upon reporting to you for duty, I was assigned by verbal orders on thé 16th of November last, to the charge of this survey and examination, then in progress under Mr. S. E. McGregory, civil engineer and assistant, who had commenced the work early in October. My first duty under this order was to find the party, which I accomplished by the 20th of November, coming up with them about a mile above the head of Cabaret Island, to which point their surveys had extended. Mi McGregory had made a complete triangulation of the river and banks from Hop Hni

low, about 2. miles above Alton, and had run a transit line on each bank connected with his points of triangulation. The harbor of Alton had been sufficiently sounded to enable the shoals anıl sand bars to be projected, as well as to define other obstructions to navigation. Thorough observations had been made at the month of the Missouri River to deterinine the extent of the abrasion of the Ilinois shore opposite the mouth, and the examination of the channel west of Mobile Island, and generally known as Mobile Chute, as ordere l by you, had been mue. A line of levels hall been run along the Illinois shore from the mouth of Wood River, below Alton, to a point a short distance above the village of Madison, thence up the river on a lino parallel to the river bank, a short distance from it, for about a mile, thence across the valley of Long Lake, along the top of the like erected there, to the bluff's. I was instructed to make as thorough examinations of the river, and particularly of the harbors of St. Louis and Altun, as the means at our disposal and time would sulmit of; also, to ascertain, as far as possible, the changes that had taken place since the surveys of former years, to ascertain the extent to which the banks had suttered abrasion, to determine the weak points, and to report the general condition of the river throughout the portion under survey. As it was then late in the season, with a prospect of cold weather setting in and closing up the work before it could be finished, I determined to reorganize the survey so as to get over is much ground as possible before cold weather and ice should set in. I therefore directeel the party then at work to continue the triangulation down to the River Des Peres, the southern boundary of the city of St. Louis, and organized another party to run a transit line from the Des Peres to the Maramec River, with instructions to locate all prominent points, bends, and islands, and to note the track of steamers whenever practicable, the party above to connect with this party. 'Meanwhile l organized a hydrographic party, and placed it under the immediato charge of Mr. H. L. Koons, civil engineer, to sound the harbor of St. Louis from the foot of Cabaret Islane to the lower city limits, operating from the base lines established by the shore parties. By the midille of December the ice had forined in the river, materially interfering with the work. The sounding was therefore discontinued, and the field parties, excepting those engaged in tinishing the triangulation and topography, ordered in. The latter work was continued, with many interruptions from inclement weather, until the latter part of January, when tield work ceased.

From the city of Alton to the Maramec river, a distance of 41} miles, measured along the channel of the river, the Mississippi winds through the valley bounded on the east by the bigh lands kuown as the Kaskaskia Blutts, and the Missouri Bluffs on the western side. The former extend from the Kaskaskia, or Okaw River, in Randolph County, Illinois, to the city of Alton, at a distance of' from five to eight miles from the river; thence the range continues to the mouth of the Illinois River, the bluntfs rising abruptly above the surface of the Mississippi to a height of from 100 to 200 feet. The opposite banks of the Mississippi, from the month of the Missouri for many miles up, is composed of a light alluvial soil, rising abruptly, though to the height of but few feet above oreli nary stage of water, in some places heavily timberol. In fact, for several miles the Missouri and Mississippi Rivers are only divided by a narrow tongne of land.

The Missouri Bluti's are met with about four miles above the junction of the two rivers. The blutis are nearly parallel in general direction, with the river alternately approaching and receiling from it. From the Des Peres to the Maramee they are, in reneral, close to the river.

The strip of land between the kaskaskia Bluff and the present course of the Mississippi is known as the American Bottom, averaging, as stated above, from tive to eight miles in width. It is composed of light alluvial soil, with some clay and sand of very little consistency. Underneath is a stratum of quicksand. The Mississippi has, undoubtedly, in the centuries that have elapsed, occupied successively every point between the Kaskaskia and Missonri Blufts. These bottoms are subject in many places to overflow it medium stages of water; at high stages, partienlarly when the Missouri and Mississippi reach this stage at the same time, the entire bottoms are submerged. These floods create considerable damage at times by washing away banks, compensating partially, however, by leaving a crust of alluvium over the more stable portions. Considerable soil is also washed down from the bluffs during heavy rains. Extensive lerees have been erected to prevent the incursion of floods from the Missouri and Mississippi, and to prevent the backing up of the water from Cahokia Creek. These levees form a cateh-water basin during rains, the water eventually going off by evaporation, leaving the sediment to add to the soil. The bottoms throughout are intersected by minor streams, which serve to drain off the surface water. The principal of these, within the limits surveyed, are Long Lake and Cahokia Creek--the former during the dry season a dry, narrow ravine; the latter emptying into the Mississippi near the fort of Bloody Island, opposite St. Louis, and, excepting in the rainy seasons, hardly more than a small ravine.

The river scarp, on the Illinois side, throughout the whole distance surveyed, is particularly liable to wash and abrasion, and immense masses of bank cave in after every rise in the river. In fact, any slight disturbance at the foot of the scarp is followed by

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