APPENDIX C.

REPORT OF CAPTAIN E. H. RUFFNER, CORPS OF ENGINEERS, UPON THE IMPROVEMENT OF THE MISSISSIPPI RIVER BETWEEN THE DES MOINES RAPIDS AND THE MOUTH OF THE ILLINOIS RIVER.

UNITED STATES ENGINEER OFFICE,

Quincy, Ill., July 20, 1886.

SIR: I have the honor to submit the following report of operations for the improvement of the Mississippi River from the Des Moines Rapids to the mouth of the Illinois River, Illinois and Missouri, for fiscal year ending June 30, 1886.

Having made a personal inspection of the district, from the 22d to the 26th June, and examined the condition of all works of construction, and also the needs of various points of bad navigation, I recommended that the first work to be done be the repair of three closing dams at and near Slim Island, which were put in in 1879, and now needed considerable repair in order to maintain the existing good condition of the channel and river in this vicinity.

Previous to doing this it was found necessary to repair a break in the shore protection and east end of the closing dam at Denmark Island, covering a distance of 487 feet.

Material used.

Stone..
Brush

-cubic yards. - 1,238.89

970.61

Total cost, $2,089.02, or about $0.945 per cubic yard. The repairs of the closing dam between Carroll and Coon Islands, consisting of strengthening the shore protection, and raising the dam to 5 feet above low water, were completed in July.

Total cost, $3,681.29, or about $0.908 per cubic yard. The repairs to the closing dam between Carroll Island and the Illinois shore were similar in character to the last described. Begun in July, finished in August.

Total cost $7,212.98, or about $1.052 per cubic yard.

_number_. 1, 592

The repairs to the closing dam between Slim Island and the Missouri shore, similar in character to the above, were begun August 29, and completed in September.

Total cost, $4,566.96, or about $0.910 per cubic yard. On September 20 a closing dam was begun across Westport Chute, about 800 feet below the head of the island. The dam is about 1,100 feet long, and consists of a brush sill 60 feet wide, weighted with gravel, dredged near Hamburg, and on this a dam composed of alternate layers of gravel and stone. Shore protections on Westport Island 800 feet in length, and 500 feet on the Missouri shore, were also placed. The dam was nearly completed by the end of October, and low water forced a suspension of work.

Dredged material, cubic yards 9,928 of which probably one-half may be considered as remaining in the dam. Total amount of material in the dam, 16,600 cubic yards. Cost

of dredged material, $0.094 per cubic yard; cost of stone and brush, $0.811 per cubic yard; total cost of the work, $10,409.45.

On October 22 a beginning was made towards a closing-dam across the small chute between North and South Fritz Islands. This dam is about 420 feet long, of the same construction as that at Westport Chute, but there being no gravel within a reasonable distance brush was used in the body of the dam. Protection on North Fritz 200 feet in length, and on South Fritz 150 feet below the dam and 450 around the head of the island. This dam was completed in great part and the fleet left November 21 for Cincinnati Landing.

Raising the crest and additional material are needed on the Hickory Island Dam.

Total cost, $4,161.51, or about $0.83 per cubic yard. The revetment at Cincinnati Landing, hastily and temporarily put in in 1879, bas never been completed, and an attempt was made to do as much as possible before cold weather stopped operations. Most of the work was riprapping simply, but brush was also used.

The old work has been fairly connected, and will now stand.

The contract for dredging in Quincy Bay was completed early in August by the contractor, H. S. Brown.

During the execution of this contract there have been dredged in Quincy Bay, principally from the bar at the mouth of Whipple Creek, 81,117.14 cubic yards of material at 14 cents per cubic yard, giving a total cost of $11,504.80. The inspector's salary and the expenses of certain protection work done at the mouth of the creek to restrain its floods, amounted to $994.75, making $12,499.55 for the cost of the improvement of Quincy Bay, and covering, within 45 cents, the original allotment for that purpose, made to conform to the clause in the appropriation bill. To the channel cut through the bar the low-water season did no damage, but the high water of the spring completely reformed the bar. No channel is found there now.

HICKORY CHUTE.

It having been reported to me that only 4.2 feet was found on the bar at the foot of Hickory Chute, the dredge, launch, and dumps were sent there from Westport Chute November 22, and the channel was widened and deepened as a temporary relief. Amount dredged, 4,819.44 cubic yards; cost, $232.46, including only the actual expenses for the actual time.

WYACONDA BAR.

This bar had only 4.5 feet at the lowest stage, and was the most important and difficult question in the district. A wing-dam built above it in 1884, and a closing-dam from the island opposite La Grange to the Illinois shore, built in 1884, below the bar, and a channel dredged through the bar in 1834, did not seem to give a permanent relief.

It was noticed from the surveys, however, made in the fall of 1884, spring and fall of 1885, that the deep curves seemed inclined to work down through the bar so as to give a channel where wanted; and to test it thoroughly the dredge, launch, and dumps were sent there so as to begin work November 2 on the down-river side of the bar. Work was continued without interruption until November 20, when this plant was laid up for the winter. Beginning at a point on the upper end of the cut, where there was a depth of 3 feet below low water, an area was excavated to a depth of 4 feet below low water, about 245 feet wide, and long enough to connect the similar curves above and below the bar. Seven and a half cuts were made, and the average length was about

1,000 feet. Some filling occurred at first, later but little was noticed, and to date it appears to be able to scour out as fast as filled. The set of the current is entirely that way now, the old crossing filling up, and this channel has been maintained and is now in use.

Total material dredged, 16,696.06 cubic yards. Average amount dredged per day, 1,077.2 cubic yards.

Total expenses of the plant while engaged upon this work and of the Coal Bluff for towage, $1,023.79. Average cost per cubic yard excavated, $0.0613.

In the spring, as soon as the weather would permit, arrangements were made, in accordance with approved plans, for beginning work on the repair of the dam at Oyster Island, opposite La Grange.

A party was sent out to cut brush on Cottonwood Island, March 18. On March 22 barges were towed up to La Grange and left to be loaded with stone, and on the following day three mooring mats were sunk above the break in this dam. The opening was found to be about 80 feet wide on top and worn to a depth of 12 feet below low water. A good apron 120 feet long was put in to begin with, and the gap was then substantially filled up with rock and brush to a height of 5.5 feet above low water, having a width of about 8 feet on top. In addition a sufficient quantity of rock was deposited on the dam formerly built for a distance of about 30 feet out from each end of the place repaired to raise the whole to grade.

The whole was completed March 30, and the fleet returned to Quincy and laid up on account of high water.

Stone
Brush...

Amount of material put in.

.cubic yards.. 1,104 .__do____ 711

After this no work of construction was done except the repair of a break 40 feet wide and 22 feet deep, at a 14-foot stage, in the brush-fence dam opposite Quincy. This was done by driving a row of piles 4 feet apart, and arching up stream and around the break; mats of poles were sunk on the up-stream side so as to reach sufficiently high on the piles, then fascines were sunk perpendicularly, close together, butt-ends, down on the upper side of the pole work; and finally, a mat 70 feet long was sunk close to and at the upper side of the mended gap and for the full length of the new work. A second mat connected this with the piles for a length of 40 feet. The whole was well rocked. Some other weak places in the dam were suitably strengthened.

Total time occupied on the work.

Total distance run by steam-launch..

Total stone in place.

Total brush in place.

Total piles driven.............

days.. 61 ...miles. 78 ---cubic yards... 230 ___do___. 120 ....number. 16

Throughout the year the navigable channel has continued good; no detention in navigation has occurred except when and where mentioned in this report.