The Elwood Bend revetment, to a length of 10,240 feet, was built in 1879 of detached frame mattresses. In 1881 and 1882 over 4,000 feet of this work was destroyed. This was replaced in 1882 by wire and brush mattress revetment.

The river has since been diverted from a portion of this revetment, which is no longer subjected to the action of the current. During the past year repairs have been made at three breaks, aggregating 1,080 feet.

OPPOSITE LEAVENWORTH, KANS.

At this point a dike was constructed for the purpose of cutting off the flow across the accretions below Dike No. 2, constructed in 1895, and of impounding the water in the old shore channel along the left bank, with a view of preventing erosion along the work placed by the Leavenworth Bridge and Terminal Company on the east bank for the protection of their bridge at this point. A portion of this material was collected during the fall and winter of 1898-99, and the work was done in April and May last. The dike is two-row work, 350 feet in length, with an inshore extension of 270 feet, composed of brush screens supported on poles.

MOUTH OF KAW RIVER.

The work at this point consisted in the construction of two low dikes designed to contract and deepen the channel of the Kaw at its mouth. The object was to remove obstruction to the discharge of the river which had been caused by changes of recent years in the channel of the Missouri at this point. The dikes consist of two rows of braced piles in 10-feet bents. Dike A contains 16 bents and Dike B 14 bents. The work was mainly done in November and December, 1898, and resumed March 30, 1899, but is not yet entirely completed.

EAST BOTTOMS (MO.) REVETMENT.

This revetment, 9,000 feet long, was built in 1887. A considerable settling had occurred near the lower end of the revetment, and although the breaks were not serious it was deemed advisable to repair them before they should become so. The work was begun in November, 1898, and completed in March and April, 1899. It included the repair of about 770 linear feet of revetment.

LITTLE BLUE REACH.

Bankhead 3 A.-A violent eddy had developed below this bankhead at the date of last Annual Report and was seriously threatening the structure. Its action was checked by means of three short spurs of brush weighted with stone, built into the pocket formed by the eddy. A length of 103 feet of the lower end of the bankhead was lost. The repair of this break was done in August and September, by means of two-row pile work with the usual mattress bracing and curtains. An extensive remodeling of the structure was commenced September 13 and finished November 17. It included the lowering of the outer wall to an elevation of 2 feet above standard low water, the removal of all stone back of the post circle, the cutting down of the earth to a berm 50 feet in width, and the paving of this berm with stone 12 inches thick with a slope from 6 feet above standard low water at the inner line to 2 feet at the post circle. There was also constructed a portion of one of two groins of brush and stone designed to arrest the reef action to

which the structure was exposed. The effect of the one which was not completed was very satisfactory and eliminated to a large degree the difficulty which they were designed to remove.

Bankhead 1 A.-A large part of the material for this structure was procured, but the work was not undertaken on account of the shoal water, which made construction impracticable at the time.

Dike 2 A.-The length of this dike is 1,140 feet. It slopes uniformly from standard high water at shore to 10 feet above standard low water at end. It contains 21 bents four-row work, and 94 bents three-row work. It was built during the months of August and September.

The effect of the dike was entirely satisfactory, but unfortunately it was breached during the high water of April, leaving a gap of 320 feet between bents 7 and 39, while the shore end was flanked by a channel 100 feet wide. The repair of this dike was attempted, but found impracticable during the stage of water prevailing at the time.

MIAMI REACH.

Dike 1 B.-The extension of this dike, 300 feet to its projected length of 1,800 feet, was done in September and October. It was all three-row work.

Bankhead 1 B.-During the month of September this structure was remodeled and extended. The width of the berm was increased, and a new outer wall of two-row pile work was built. The old wall was degraded to a height of 2 feet above standard low water at the outer edge, and to a height of 3 feet at the post circle. The upper arm, for a distance of 8 degrees beyond the old limits, was graded and paved.

GLASGOW REACH.

Bankhead 6 C.-This structure was attacked by a violent eddy about the middle of July, which caused considerable damage to the upper end of the structure, and even threatened to flank it. The damage was repaired in July and August. The outer wall was somewhat extended upstream. In October and November this structure was remodeled and extended practically the same as in the case of 3 A, with some modifications due to the stage of the water at the time that the work was going on. Sounding taken at the bankhead November 30 showed a deep trench around the outer wall, with a maximum depth of 35 feet below standard low water. The trench had the effect of concentrating the flow at this point with such high velocity as seriously to threaten the structure. An attempt was made to relieve the situation by building groins similar to those which had apparently been so successful at 3 A. The difficulties at 6 C were, however, far more serious. The work was much interrupted by the cold weather and running ice, and although it was continued during the winter and spring, the results at the date of this report are still doubtful. Late in April a light levee was thrown across the low ground above the bankhead to prevent overflow, but not being strong enough was breached by the high water. A new levee of sufficient size to insure its stability was constructed early in June. Late in the same month a line of abattis was constructed above the bankhead to aid in building up the bottom by deposit, with a view to future extension of the upper arm of the bank head.

Dike 3 C.-This structure is 500 feet long, of four-row work for 27 bents, and three row for the remainder. The grade for 30 bents from the shore was level and 13.25 feet above standard low water, dropping

thence to 10 feet at the outer end. This work was done in October and November.

Bankhead 5 C.-Anticipating similar trouble to that experienced at bankhead 6 C, the construction of four groins was undertaken at this point-one in the eddy above the bankhead, one in that below, and the other two at intermediate points. The one below the bankhead was not built. The action of the upper groin in breaking up the eddy was very effective. At about the time of the completion of this groin certain changes in the regimen of the river produced an attack of extraordinary severity upon the bankhead, causing the upper groin to settle, and endangering the stability of the entire structure. To meet the emergency, a two-row pile extension of the post circle was ordered built along that portion of the bankhead where the action of the river was most dangerous. This work was in progress at the close of the year.

A levee 60 feet long was built back of this structure to a height of 19 feet above standard low water to prevent flood water passing around it.

Bankhead 4 C.-This structure has not been in the line of active flow during the year, and no work has been done upon it.

Bankhead 2 C.—The construction of this bankhead was begun October 6, at the foot of Little Missouri Bend, and was left in an unfinished state. It presents some new features based upon experience in building other works of its class.

Dike 3 C.-Some damage was done to this work by the ice during the months of November and December, but it was promptly repaired at slight cost. During the spring flood about 200 feet of the outer end was carried away.

Abatis below Dike 3 C.-This work was designed to cause and maintain a high crossing into Wilhoites Bend. The work was begun June 23, but on account of the quantity of drift running was suspended on the 29th.

CAMBRIDGE BEND REVETMENT.

The lower end of this revetment had been partially destroyed, and was further threatened by a violent eddy which had developed at that point. To prevent further damage a curved line of 2-row pile work, extending from the revetment above the break to a point some distance below, was built in November last. Two radial curtains were also built from the pile work to the bank to cause the pocket to fill up.

ROCHEPORT REACH.

Bankhead 1 D.-Between the dates of October 8 and November 3, this structure was remodeled in a similar way to that of bankhead 3 A. The work stood well until early in June, when a part of it was carried away by the flood. Repairs of this break involving an extension of the bankhead according to plans previously prepared, but modified somewhat on account of the stage of the river at the time, were begun on the 25th of June, and were in progress at the close of the year.

HUNTSDALE REACH.

The project at this point contemplated the construction of two lines of abattis, aggregating 700 feet in length. The work was done during the month of December, and has accomplished the object for which it

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was designed in filling up the bend where the caving was going on. It is probable that additional work will be needed to protect the bend at a point farther downstream.

GASCONADE DIVISION.

NEW JUNCTION OF MISSOURI AND OSAGE RIVERS.

The operations at this point have consisted in the removal of deposits that had collected in the cut during the period of high water; in opening a new ditch 800 feet long beyond the north end of the cut; in the construction of three cross curtains designed to cause a deposit between the embankment and pile work of Dike 193 A, and in the removal of various obstructions in the proposed waterway. The shore end of Dike 19 B was cut down to grade. Dike 193 A was repaired. Some repairs were also made to the embankment where it had been injured by the floods. The conditions of high water have not yet been such as to develop the proposed new outlet of the Osage.

Dike XXIII-A break in this dike was discovered on the 12th of August, but it is believed to have been caused by the previous flood. It was repaired in October.

Dike 16 A.-The outer 54 feet of this dike was cut down to a grade rising from 0.3 feet above standard low water to its old grade 7.9 feet. Dike XXIV.-The bracing of this dike, which had never been put in, was constructed during the month of November.

Dike XI B.-A groin was built across a hole which had developed at the end of this dike. This work was done in the first week of April. Hardin's Island.-A line of abatis 500 feet long was constructed at this point in November, with a view of eliminating the Hardins Island crossing. The work produced good results, although it did not fully accomplish the object proposed. Between November 18 and December 3 the line of abatis built in 1899 was extended 657 feet across the chute at the head of Hardins Island. This work suffered some damages from the succeeding high water, but they were repaired at slight expense.

Chamois Bankhead.-This structure, the first of its kind built, has withstood remarkably well the attacks of the river. The only work, except some minor repairs, that has been done upon it during the year consisted in the construction of two groins across the trench along the front of the bankhead, with a view to causing it to fill up. Changes in the regimen of the river which had become apparent early in August indicated that the channel was shifting away from the bankhead, but this tendency was in part counteracted by the abatis at Hardins Island.

HOWARDS BEND BEACH.

Bankhead 4 F.-Work on this structure consisted in fairing out the outer wall over a part of its length and reenforcing different parts of the work. This work was done between October 24 and November 3.

Bankhead 5 F.-Work on this structure consisted in some minor repairs, in fairing up the outer wall over a portion of its length, and in reenforcing the work at various points. This work was done between September 19 and October 22.

Bankhead 6 F.-Four groins were constructed at this bankhead, with the same objects in view as in the cases of bankheads 3 A and 6 C, and some work for the extension of the bankhead upstream. The attack

upon the bankhead by the spring floods was very severe, but serious damage to the structure was prevented by the work done.

PELICAN BEND REVETMENT.

Between August 15 and December 8, 6,450 linear feet of revetment, standard specifications, was built at this point. During the latter part of the month of June preparations were in progress for the resumption and extension of this work under the appropriations of January 5, 1899.

DAMAGES.

The most important injuries sustained during the year by works under charge of the commission, in addition to those already mentioned, are as follows:

Council Bluff revetment.-During July, 1898, a large break, about 2,700 feet long, occurred at the head of the Council Bluffs revetment. This break was covered by a railroad company, whose tacks it protects. During the spring flood of 1899 another break of 1,600 feet occurred. The floods of this year have continued for a longer period than usual and have subjected all work to severe strains.

PLANT.

No new plant of importance was acquired during the year. The existing plant was cared for as heretofore, and the necessary work for maintenance and repairs was done. In addition to the towboats belonging to the Government, four private boats were chartered at various times. There were wrecked and lost during the year three 100foot barges. Provision has been made for increasing the plant this year by the building of twelve new barges.

SURVEYS AND REPORTS.

In connection with the progress of the work, frequent surveys were made showing the conditions at the various points, and also numerous special examinations and reports upon different localities.

For details of the work see the reports of Division Engineers Fox and Yonge, Appendices E and D, respectively; also reports of Division Engineer Fox, Appendices F and G.

OSAGE RIVER.

The project for the improvement of this stream, adopted in 1871, consisted in the removal of obstructions to navigation, such as snags and leaning timber, in deeping the channel over shoals by means of dredg ing, and in the construction of cross and wing dams to concentrate the water over the shoal places.

The original estimated cost of the project was $230,000, but afterwards the work was made to cover more ground than was originally intended, and for a number of years past no estimate of the cost of the improvement by this method has been rendered in the annual reports. From the nature of the project, which contemplates only temporary relief from year to year and the removal of obstructions which are con stantly forming anew, no definite time can be fixed for its completion, and no estimate made for its ultimate cost. The improvement must be continuous, and the annual estimates must depend upon conditions as they arise.