APPENDIX C.

REPORT OF CAPTAIN SMITH S. LEACH, CORPS OF ENGINEERS, UPON OPERATIONS IN THE FIRST DISTRICT.

UNITED STATES ENGINEER OFFICE,

Memphis, Tenn., July 25, 1887.

SIR: I have the honor to submit the following report upon the work of improving Mississippi River, first district, for the fiscal year ending June 30, 1887.

From the beginning of the year until October nothing was done except the care of the floating and other property.

Early in August the passage of a river and harbor bill gave hope of a resumption of operations, and to provide for this, as well as to restore the plant to a proper condition, from which shortage of funds for two years had caused it to greatly deteriorate, a thorough repairing was undertaken.

Prior to the general allotment of the appropriation by the Commission preliminary estimates for this purpose were sent in and were approved by the Secretary of War. The amount allotted to the first and second districts was $20,000. This sum was expended almost entirely in making the floating property sea-worthy and weather-proof. Experience having shown that, in view of the first cost, cost and frequency of repairs, and danger from fire and unexpected leaks, the canvas roofs heretofore used are not suitable for the purpose, a change to tin was made for all roofs except those of steam-boats and two shingle-roofed quarter-boats. The work amounted to 899 squares. It was done by contract, at $7.60 per square. Some deductions for assistance rendered and board of mechanics reduced the actual cash payment to the contractor to $6,619.40 The new roofs have given entire satisfaction. Aside from this, the expenditures were principally for labor of calkers and carpenters, and for lumber and oakum devoted to calking and repairing of gunwales, rakes, and decks. A small force of mechanics was employed in overhauling machinery and other work preparatory to putting pile-drivers in commission.

At a meeting of the Commission in September an allotment of $377,250 was made for continuing the work on Plum Point Reach. Notification of the approval of this allotment was received on the 22d of November, and a project for its expenditure was at once submitted.

Later new projects in greater detail were called for, and as much time had already been lost, and the working season was nearing its close, a partial project covering work of most urgency was hastily prepared and returned at once (December 8). This project contemplated repairs to the Plum Point system of dikes by closing breaks, and to the Bullerton No. 2 dike by a re-enforcement throughout its length. The estimate was $40,000.

Notification of the approval of this project and estimate and authority to begin work were received January 11, and the necessary preparations were at once begun. Before materials could be collected the spring rise set in, and nothing further could be done until April, when work on the Plum Point system was begun with a small force and prosecuted, with interruptions from high and low water, until completed. Dike No. 5 had two breaks, with the intervening portion much damaged, and was rebuilt from the inner side of the inner gap to the outer en 1 of the dike, a total length of 800 feet.

Dike No. 6 had also two breaks, but farther apart. The ends adjoining were good and the breaks were closed at small cost. All the work was of the standard threerow dike. No tipped or foot mats were used. The tipped mats of the original dike had broken down and disappeared, and it was not thought advisable to make the new work less permeable than the old. In all cases the old foot-mats were found in place and sufficient penetrations through them were procured, thus securing the new work against undermining without the cost of new foot-mats. The outer end of each dike was strengthened by three clumps of three large cypress piles each, driven as deep as possible, and strongly fastened to each other and to the dike. In the immediate vicinity of the new work its favorable results are already apparent. A longer interval of time and higher prevailing stages of water will be requisite to develop the effect of these repairs in increasing the efficiency of the Plum Point system.

At almost the very hour that the first tow of cypress piles designed for the reenforcement of Bullerton No. 2 dike, under this same project and estimate, arrived at the head of the work, that dike broke, and its repair became an entirely new question. After the decline of the flood the dike was found in such condition as to make the cost of repairing it far greater than its value when done. Since the close of the year a new dike, below the old one, has been proposed and approved. It is hoped to complete it without exceeding the original allotment.

The total expenditures from this allotment have been $9,722.60, of which $7,460.77 was applied to the Plum Point repairs. The difference, $2,261.83, represents the value of materials and supplies on hand available for the new dike proposed.

On December 30, 1886, a project for the expenditure of the remainder of the Plum Point allotment was forwarded to the president of the Commission. This project provided for the extension of the Fletcher revetment, to cost $180,000, and the completion of the closure of Elmot and Island 30 chutes by dikes near their lower ends, the two estimated to cost $130,000. This project was approved by the Commission and forwarded to the Secretary of War. It was referred by the Secretary to Congress, raising the question as to whether the proposed revetment traversed the limitation placed by Congress upon that class of work. The project and all the correspondence are published in Ex. Doc. No. 88, Senate, Forty-ninth Congress, second session. No further action had been taken up to the close of the fiscal year, but since that time the amounts named have been withdrawn and reallotted to levees. The allotment of $100,000 for levees on the Plum Point Reach was approved by the Secretary of War, and notification of that fact reached me on the 9th November. The work was at once advertised, and the bids were opened on the 25th: The following bids were received:

The award was made to the lowest bidders, Messrs. J. S. McTighe & Co., of Memphis. They began work on December 2, and pushed it with most commendable energy. The conduct of the gentlemen composing the firm, individually as well as collectively, left no room for doubt of their determination to fully and cheerfully meet every obligation, expressed or implied, which their contract imposed upon then. Previous experience led me to expect interruption of such work by high water about February 15, and that date was fixed in the contract for the completion of the work. The work was seriously interfered with on the 16th, and on the 21st was brought to a stop. By this time the work was practically completed, so far as the restriction of overflow was concerned. But for two weeks of freezing weather in January, during which time frost penetrated the ground to a depth of 9 inches-a very unusual thing for this latitude-the work would have been completed within the contract time, except the sodding, which I had postponed, in the interest of the United States, to a more favorable season. Observations during the overflow convinced me of the desirability of extending the work at the upper end a short distance beyond the terminus first selected.

An extension of the contract to the time when the sodding could be safely done was necessary, and finding sufficient funds remaining, I took occasion during the extension to order the additional work done. The levee as completed consists of two parts, joining near Ashport in a very obtuse angle. The new levee extending down the river is 55,000 feet in length, and extends to the upper end of the Plum Point dikes. The flank line, or "old levee," is 8,800 feet long, and joins a piece of fairly good levee extending 2 miles farther. Both are built with 3 and 3 to 1 slopes, and crowns of 6, 8, and 10 feet, the one nearest the height being used. The specifications were based on those previously used for the United States levees.

During the high water and while the levee was soft the only trouble experienced was from wave and rain wash and sloughing. Nothing alarming occurred at any time. Sacks and bagging were supplied, and a small patrol and repair force was kept employed. The latter, in addition to insuring the safety of the levee, accomplished much in the direction of redressing it for sodding.

The effect of this levee in restricting the escape of water from the river has been most gratifying. The sum allotted was less than half the estimated cost of a levee to completely stop the overflow; but its application to this line has had the effect of stopping all but the small amount of 20,000 cubic feet per second. This fact was determined by careful and repeated observations during the high water, and has resulted in a determination not to build the rest of the line, at least until other openings on the reach, where more good can be done with the same money, are closed. The effects of the increased volume of water upon the channel have been marked, and in the aggregate beneficial. The caving of banks in the channels through which the volume of flow was considerably increased was noticeably accelerated. The channel at Island 30 crossing, where the increased volume was first concentrated in a single stream, was deepened by several feet.

The total channel area in the stretch of river where concentration has been effected was considerably increased by the lowering of 8 to 10 feet of the crests of three middle bars. This example is as free from extraneous complications as can reasonably be hoped for, and it can scarcely be doubted that the prevention of overflow by this levee and the enlargement of channel in the vicinity, immediately following, stand to each other in the relation of cause and effect.

The slope observations indicate a greater fall of water-surface during the flood of 1887, restrained by the levee, than during that of 1856 not so restrained. In other words, the enlargement of channel caused by the levee was accompanied by a lower flood level, as would naturally be expected. A balance of $13,146.34 remains for this work, from which the right of way is yet to be paid. It will be used in mowing weeds and such repairs as become necessary, and if a surplus remains it will be applied to extending the line at the upper end.

The loss of channel works during the fiscal year has been comparatively small, and all from causes which can be avoided in future work. Two cross-dikes have been broken by the pressure of drift, the break in each case having been made possible by the rotting of the piles. Bullerton No. 2 was broken by the pressure of drift above it on the 9th of February, the gauge reading 28 feet, while the same dike had withstood the year before the pressure of the same mass of drift at a stage 5 feet higher, and had in addition been subjected to the impact of a large field of drift which came down from a broken dike above. The impairment of strength by another year's decay was the sole cause of its breaking. The current through the chute increased about 50 per cent. immediately after the break, but did not reach a point where any scour could occur. The bottom in the neighborhood of the dike is full of logs imbedded in the sand, and no loss of deposits previously secured has taken place or may be expected. Discharge observations made fifteen days after the break showed the discharge through the chute to be but 6.7 per cent. of the total volume of the river.

Osceola No. 1 was a comparatively small dike and one of the oldest. It broke on March 2 by the drift moving over it, the river being at nearly its highest stage. In this case, as in the other, none of the deposits already secured have been or will be lost, but remain to attest the past usefulness of the lost works. These two dikes aggregate 2,200 feet in length, and are estimated to have cost $83,500.

The only loss of revetment has been at the middle section in Fletcher's Bend. But little caving has taken place between these sections during the year, the unprotected portions of the bank having receded until they were shielded by the projecting revetments. The entire destructive effort of the river has for the past year been directed against the middle section of this revetment. The bottom has scoured to a great depth in front of it, thus throwing a violent current close to the bank, and eddies above and below have attacked it in the rear. The result has been that at the cost of a short length of revetment about 3 miles of bank have been held on a nearly stable line, and this stability of bank has played an important part in the stability of channel below, which is at once the cause and the proof of improved navigation. The loss during the year has been about 500 feet, estimated to have cost $12,500, and this sum represents the total loss of this class of work on this reach during the year.

Aside from the cutting down of the middle bars above noted as a probable effect of the levee, there have been no noteworthy changes in the depths or directions of the channels. On the Plum Point crossing, which is the only one under thorough control of the works, no depths less than 10 feet have at any time been found. This depth was only met with on two or three occasions, and for a day or two at a time, and was the result of temporary obstructions, which the current soon removed. The prevailing depths at extreme low water have been 12 and 13 feet, and at average low water 15 feet. The other shoal on the reach, known as the Island 30 crossing, carried from one to three feet less than the one just described, reaching minima of 8.5 and 9 feet. As before noted, however, as soon as the effect of the levee was felt this channel scoured out and has since been practically equal in depth with the Plum Point crossing.

The Island 30 crossing depends for its permanence of location and adequate depth almost wholly upon the maintenance of a fixed bank line in Fletcher's Bend, imme. diately above. If another year's neglect of the Fletcher's revetment allows that bend to resume its caving, obstructed navigation may be expected at Island 30.

There are submitted herewith financial statements and general balance sheet for the allotments in the first district, a list of civilian engineers, and a table of the value of plant.

Very respectfully, your obedient servant,

General Q. A. GILLMORE,

SMITH S. LEACH,
Captain of Engineers.

President Mississippi River Commission.

Appropriation for improving Mississippi River, first district.

FINANCIAL STATEMENT.

Balance on hand June 30, 1886, as per last report, including estimated

liabilities.....

Amounts received since (act of August 5, 1886):

On account Plum Point Reach.

On account levees Plum Point Reach.

On account Hickman, Ky.

On account Columbus, Ky.

Total......

Expended from July 1, 1886, to June 30, 1887:
On account Plum Point Reach....
On account levees Plum Point Reach

Balance June 30, 1887...

$1,540.56

Appropriation for improving Mississippi River, first district.—General balance sheet.