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(c) New Orleans Harbor, 963 miles below Cairo.-The city of New Orleans covers a length of about 13 miles of the Mississippi River. In that distance the river makes four bends, called the Carrollton, Greenville, Gouldsboro, and Third District bends. In all of them more or less erosion was going on, which, as the value of property increased, it became desirable to stop. The features of the case, which are peculiar and make it different from other places where the protection of banks has been undertaken, are (1) the great depth of water and steepness of the banks, which are unfavorable, and (2) the comparative stability of the banks, which has enabled New Orleans to occupy essentially her present site for a century and a half, which is favorable. The system of spur dikes was introduced in 1884, and has since been used exclusively, and has thus far been successful. The spurs begin near the lowwater line and project into the river to the point where their top surfaces, having a slope of 1 upon 3, intersect the bottom. They are usually about 1,000 feet apart, but the interval may vary with the greater or less curvature of the bend.
At the beginning of the present year there had been placed in New Orleans Harbor 3 spurs in the Carrollton Bend, 2 in the Greenville Bend, 6 in the Gouldsboro Bend, and 4 in the Third District Reach, a little below the bend. During the year 4 additional spurs were built in the Third District Reach and 2 in the Carrollton Bend. They were all in good condition at the end of the year, and appear to be accomplishing the object for which they were designed. The construction of additional spurs is contemplated.
(d) Surveys, gauges, and observations.-Discharge observations during the low water of 1891 were made in the Mississippi at Red River Landing, in the Atchafalaya near Simmesport, and in the Red River at the Red River Dam, and during the high water of 1892 in the Mississippi at Natchez, Red River Landing, and Carrollton, and in the Atchafalaya at Simmesport. Local surveys were made in the vicinity of Red River Dam and at five places in New Orleans Harbor, and in connection with the location of new levees, and a continuous line of levels was run over the levees of the Tensas Front from the upper end of the district down to Fairview Landing.
(e) Levees.-The levees in this district include the lower half of the Tensas Basin and the Atchafalaya Basin on the right or west bank, a distance by river of about 432 miles, and on the left or east bank, the low country below Baton Rouge, a distance by river of about 206 miles. The local organizations for the right bank are (1) Fifth Louisiana levee district, extending from the State line to the mouth of Red River, (2) Atchafalaya Basin levee district, extending from the mouth of Red River to Donaldsonville, (3) Third Louisiana levee district, extending from Donaldsonville to the Gulf of Mexico, except about 13 miles at New Orleans. Those for the left bank are (1) Pontchartrain levee district, extending from Baton Rouge to the upper limit of the city of New Orleans, and (2) First Louisiana levee district, extending from the lower limit of the city of New Orleans to the Gulf of Mexico. The Orleans levee district includes all levees on both banks within the limits of the city of New Orleans, extending about 13 miles on each bank. Allotments by the Commission have been made under the titles "Tensas Basin, Fourth district," "Right bank below Red River," and "Left bank below Red River."
(e 1) Tensas Basin, fourth district.-At the date of the last Annual Report the levee which had been begun at Gibsons Landing (683 R) was not completed. It was finished this year. The levee at Henderson (712 R), which had been contracted for last year, was built this
year. In addition to these the following lengths of levee were constructed, viz: 9,840 feet at Hardscrabble (639 R), 11, 632 feet at Kempe. (659 R), and 136 feet at the Ferriday crevasse (693 R), containing in all 399,831 cubic yards. They were built with a crown of 8 feet, side slopes 1 upon 3, and to a height from 1 to 3 feet above high water of 1890. Work was done by the local authorities, the amount and location of which has not been reported to the Commission.
(e 2) Right bank below Red River.-After completing the levees which were reported as under way at the date of the last Annual Report, the following lengths of levee were constructed, viz: 600 feet at Nina (806 R), 8,021 feet extension at Highland (815 R), 4,743 feet at Mayflower (853 R), 3,686 feet at Fortville (855 R), 3,400 feet at Evergreen (857 R), and 783 feet at Dumboine (865 R), containing in all 435,550 cubic yards. They were built with a crown of 8 feet-except at Nina, where it was 6 feetside slopes of 1 upon 3, and to a height of from 1.2 to 3 feet above high water of 1890. Repairs were made to the levees in various places, removing weeds, replacing sods and restoring slopes damaged by rain wash. Work was done by the local authorities, the amount and location of which have not been reported to the Commission.
(e 3) Left bank below Red River.-In this subdistrict the following lengths of levee were constructed, viz: 9,258 feet at Southwood (extension) (875 L), 1,959 feet at Tessier-Bourgeois (909 L), and 1,372 feet at Southport (955 L), containing in all 165,911 cubic yards. They were built with crowns of 8 feet, slopes 1 upon 3, and to a height 2 to 3 feet above high water of 1890. Repairs were made at various places.
For details of the operations in the Fourth District, see report of First Lieut. John Millis, Appendix 7.
HIGH WATER OF 1892.
The high water of 1892, though of unusual height in the upper Mississippi-at St. Louis not having been equaled since 1858-was not of excessive height in the upper part of the main trunk below Cairo. As far down as Helena, 306 miles below Cairo, and for some distance below that, it has been exceeded half a dozen times in the last ten years. Below the Arkansas River it was the highest upon record. One of its remarkable features was the lateness of the season at which it occurred. In some cases the highest stages were not reached until after the date, May 27, at which the executive officers of the Commission rendered their annual reports. Later information seems to indicate that the maximum stage of the river has been passed, but at this writing, June 16, the water is still very high, having fallen but a few inches from the highest stage reached, referring always to the portion of the river below the Arkansas.
The information before the commission concerning the flood is at present incomplete. It seems probable that the maximum strain has been placed upon the levees which they will have to bear this year, and that but little, if any, further damage will be suffered by them. Only a very general view of what these damages are can now be given. The number of crevasses has been somewhat greater than the number last year, though insignificant compared with the number in former years of great floods. A large part of the Tensas basin in Arkansas is overflowed. There has been no break anywhere on the Yazoo front or on the Atchafalaya basin front or in the Orleans district. The local organizations in those districts had made more serious efforts to strengthen their levees than had the local organizations elsewhere. Crevasses have occurred in the Pontchartrain district and in the First
and Third Louisiana districts, but at this writing it is not known how extensive the overflow from them is. The district officers have been untiring in their efforts to hold the levees. Upon the approach of the flood the engineering staff was stationed at critical points, sacks and lumber were distributed, and steamers required for transportation and inspection were employed. In coöperation with the local authorities, the weakest levees have been under constant inspection and many repairs have been promptly made as required. That these efforts have not in all cases been successful should not be surprising. The levees require an expenditure of several million dollars to put them in a state of reasonable security against great floods. That they should yield in places during the highest flood heretofore recorded is to be taken as a matter of course.
LOW WATER OF 1891.
The stage of the river in October and November, 1891, though not the lowest upon record, was so low as to seriously obstruct commerce. Most of the steamboats and barges were laid up, and such as continued to run were compelled to carry greatly reduced loads. The large grain crop of this country and the great demand for it in Europe rendered this an unusually serious misfortune. Millions of bushels of wheat which had been sold in Europe were lying in the elevators of St. Louis, without means of transportation, while the grain barges were tied up at the bank. Urgent demands were made upon the commission for relief, by a temporary removal of the crests of the most prominent bars by dredging, and several devices for accomplishing that result, very easily as the designers supposed, were presented. The idea of procuring temporary relief to navigation during the low-water period at a small cost is a very attractive one and has at one time or another engaged the attention of probably every engineer, including the commission, who has been employed upon the river. It would seem at first glance to be a simple matter to shave off the crests of a few of the more prominent bars and thus materially increase the draft to which vessels may load. Long's scraper and the portable wing dam of Adkins and Keiser are among the devices to accomplish this object which have been built and tried and have failed, while those which have been designed and proposed are innumerable and of every description. The difficulty in applying successfully any of these devices lies in the great building power of the river, the inconstancy of its flow, and its great width. It is essential that the device, whatever it be, shall not oppose the tendency of the river, but shall aid it. In a river a mile or two wide, with perhaps several channels of equal dimensions, it will often be difficult to tell by casual observation which one of these channels it is tending to enlarge or abandon. The tendency one day may be reversed the next by a sudden rise or fall in the river's stage. Hence the commission has never been sanguine about the possibility of obtaining useful results from experiments with dredging appliances in the Mississippi. It condemns without hesitation all devices which rely exclusively upon the current of the river for carrying away the excavated material. However useful such devices may have proved upon small streams, upon bars of moderate dimensions, no good results can be expected of them in the Mississippi, where the distance across the bar is often a mile or more. Likewise, it condemns all appliances of small capacity, such as the dredges to be found in ordinary use. Where hundreds of thousands of yards of material must be moved, and moved promptly, some quicker and cheaper appliances than those are needed. In the judgment of the commission some dredge of great capacity, which can
remove the material bodily and can itself be easily moved from place to place, is essential in order to give a reasonable chance of success.
In view of the very serious loss which the trade of the valley was suffering from the obstructions of last autumn, the commission, though not very sanguine, was willing to try the experiment of dredging, provided a dredge such as it considered essential could be secured. There was but one such in the Mississippi River, the dredge Bailey, employed at the South Pass. Efforts were made to obtain her, but they were fruitless, her services being required by her owners at the South Pass. The commission has had under consideration the propriety of building a dredge for this experiment, but in view of its very considerable cost has not yet concluded to do so.
The obstructions during the low-water season were of course greatest above Cairo. Between Cairo and the mouth of White River, there were 42 crossings giving less than 10-feet channel depth, of which 35 had less than 9 feet, 26 less than 8 feet, 21 less than 7 feet, 8 less than 6 feet, and 1-at the head of Island 40-had 5 feet.
Appropriation for salaries and expenses Mississippi River Commission:
Balance on hand July 1, 1891...
Refundment by Capt. Powell, for account Mississippi River Commission....
Through the Chief of Engineers, Washington, D. C.
LETTERS OF THE MISSISSIPPI RIVER COMMISSION SUBMITTING ESTIMATES FOR THE FISCAL YEAR ENDING JUNE 30, 1894.
ST. LOUIS, Mo., August 16, 1892.
GENERAL: Your letter of August 4, calling for estimates from the Mississippi River Commission for the fiscal year ending June 30, 1894, failed to reach me in time to be laid before the Commission at their recent meeting.
It was supposed by the Commission that estimates in the usual form would not be required, since the act of July 13 specifically designated the amount which can be expended during each of the four years provided for. It was, however, supposed that a recommendation covering a detailed project for this expenditure would be required before the next meeting of Congress, and instructions were given to the secretary and to the district officers to have projects prepared for works under their charge in time for the next meeting of the Commission, November 5, 1892. As these projects are intended to cover the whole amount allowed by law for the year ending June 30, 1894, after deducting the $1,500,000 already recommended for expenditures on levees during that year, the gross estimate of the Commission for the fiscal year ending June 30, 1894, may be placed at $2,665,000. Separate estimates for continuing work on harbors have already been submitted.
Very respectfully, your obedient servant,
CHAS. R. SUTER,
Brig. Gen. THOMAS L. CASEY,
THE MISSISSIPPI RIVER COMMISSION,
New York City, August 8, 1892.
GENERAL: In compliance with the requirements of the river and harbor acts of 1866 and 1867, I have the honor to submit estimates for improvement at certain points on the Mississippi River, for the fiscal year ending June 30, 1894, viz:
Lieut. Col. of Engineers, President pro tem.,