Atchafalaya system into the Mississippi; or, otherwise stated, Red River proper has then two outlets or branches, one through the Atchafalaya and one into the Mississippi, while the discharge of the Mississippi is confined entirely to its own channel. In the second case the discharge of the Red and Atchafalaya is confined to its own channel, while a portion of the water of the Mississippi is diverted from that river and passes down the Atchafalaya. In the third case the two river systems are independent so far as their discharge is concerned, which is then practically the same as would be the case if no connection existed. During the flood period other influences have a material effect. The levee system on the west bank of the Mississippi is only completed down to Bougere, about 26 miles above Turnbull Island, and breaks in the levees above sometimes occur. The water from the Mississippi that escapes through breaks or crevasses above and that flowing over the bank between Bougere and Turnbull Island fills up the basin of the Lower Red and tends to maintain an equilibrium in the stage of the water in the two systems at Turnbull Island, and so prevent a current through the Old River. At such times there is a general set southward of the water covering the low swamps between the Lower Red and the Mississippi, forming a cross current which is partly interrupted by the high ground on the northwest portion of Turnbull Island and entirely stopped by the levee along the south bank of Lower Old River. The water from the Mississippi being much more heavily charged with sediment than that from the Red and its tributaries, it seems very probable that under these conditions the rate of filling, particularly in Upper Old River, is materially accelerated. Since the bottom of Upper Old River has filled up to a level of about 13 feet above the zero of Barbres gauge, all action of a current from one river system to the other below that stage is contined to Lower Old River, and at higher stages the scouring action is no doubt weakened by being divided between two channels instead of being confined to one. The condition of absolutely no current through Lower Old River is comparatively rare, but the two river systems have at times remained at so nearly an equal stage while falling that not sufficient current between the two was formed to move the sediment that had been deposited during high water, and entire closure of the Old River channel during low stages has resulted. Another serious difficulty has been experienced, due to the caving or sliding down of the soft banks of Lower Old River. The present channel being much narrower than when the main river occupied it, the banks are in many places of very recent formation. When the river falls to a very low stage the water is held in the adjacent ponds and sloughs at a higher level than in the channel, and the underlying strata of the banks are kept saturated. When no longer supported by a high stage of water in the channel, large masses of the soft banks slide down, and their weight causes lumps and ridges of the stiff clay comprising the bottom of the channel to rise up, frequently stopping navigation entirely until these lumps and ridges can be cut out. The general object of the works of improvement now in progress is to rectify the defects above outlined, and the present project proposes to effect this by causing a separation of the Red from the Atchafalaya at Turnbull Island for all stages of these rivers below medium low water, making the Red a proper tributary to the Mississippi when it is at or below this stage, while the Atchafalaya becomes at the same time an outlet or "diffluent" of the Mississippi. The plan also contemplates preventing any further enlargement of the Atchafalaya, and the whole work is designed to have no material effect on the high-water regimen of the various rivers involved, and to produce no greater danger of injury to property from overflow than now exists. This general project contemplates the following work: A series of low relief dams or sills, not to exceed six in number, to be built in the Atchafalaya proper at intervals of about a quarter of a mile. These dams to be located below the mouth of Bayou Des Glaise, near Simmesport, about 5 miles below Turnbull Island. These dams are designed to prevent further enlargement of the Atchafalaya and to limit its discharge capacity. They are to be built up of successive layers of mattresses made of willow brush and timber, ballasted with stone, and with intervening layers of mixed gravel and clay; the foot mattresses to have a width up and down stream of about 300 feet, and the maximum depth over the crest of the dam to be about 7 feet at extreme low water. The high-water discharge over these dams is intended to be equal to the flood discharge of Red River proper, or about 200,000 cubic feet per second. A low relief dam is also to be built across the river from the west side of Turnbull Island to the mainland. This dam to be constructed of successive layers of willows and timber mattresses, with stone ballast, and its top and side slopes to be heavily paved with rock. The foot mattress has a maximum width up and down stream of 280 feet. The total length of the dam proper is 935 feet and of the shore-protecting mattresses about 2,039. This dam is to effect the separation of the Red from the Atchafalaya at all stages of the water below the level of its crest and deflect Red River through Upper Ŏld River. To complete the separation of the Red from the Atchafalaya a canal is to be cut from Upper Old River across Carrs Point to the Mississippi, and a dam or obstruction is to be built to close Upper Old River below the canal at some point opposite the eastern end of Turnbull Island. To secure a navigable channel through Upper Old River it is to be deepened by dredging or otherwise, as may be found most expedient. During the progress of the above work an attempt is to be made to temporarily maintain navigation through Lower Old River by dredging, washing the bottom with steam tugs, or by other expedients. Up to the time of the last Annual Report the following work had been accomplished: Two of the sill dams in the Atchafalaya, Nos. 1 and 3, had been completed. The sill or foot mattress and shore protection of the Red River Dam were finished. The two lower courses of crib mats were in place and the third course had been constructed and a portion of it sunk in place. Considerable dredging had been done both in Lower and Upper Old River, though the latter had not proved effective, owing to the nearly fluid state of the material in which the work was done. The site of the proposed Carrs Point Canal had been partially cleared of trees, and dredging at the western end in an experimental way had been commenced. The telephone line to connect the works with West Melville, the nearest telegraph station, was partially completed and repairs to the barges and other portions of the plant were in progress. The Commission having directed that the dam be raised temporarily to a height of 5 feet above low water, or the zero of Barbres gauge, in order to assist in increasing the current and consequently the scour in upper Old River during the falling stage of the water, work on the dam was resumed and continued until four courses were in place and a height of about 3 feet above the zero of the gauge obtained. The fourth course was not entirely completed. The river continued to fall rapidly, finally reaching the unusually low stage of 1 foot below zero on November 17, and it became necessary to suspend work and carry out the instructions of the Commission given in anticipation of a season of extreme low water, and to remove a portion of the dam to permit boats to pass while the low water continued. A part of the upper course of mats was therefore cut out by means of a dredge, leaving over the dam a clear channel, which for a width of 450 feet has a depth of about 5 feet below the zero of the gauge. In making this cut the rock taken out was distributed over the apron below the dam. Meanwhile dredging was continued in upper Old River, but with no greater success than had attended previous work of the kind in that locality. In lower Old River the usual difficulties were experienced in maintaining the channel during low water, but to a much less degree than ever before at a corresponding stage of the water. Dredging began as soon as the water had fallen sufficiently to permit the dredge to work and was continued until the water became so low that the work had to be suspended. The Government dredges Menge and Pah Ute and a Hayward bucket dredge, hired for the purpose, were used for this work, and operations were confined to the sand bar at the Mississippi end of Old River, to the "Second Crossing," and to the clay lumps and ridges in the vicinity of Ash Cabin and Dead Tree. There was also a shoal place near Kellers, in the western portion of the lower Old River, caused by a deposit of sand, and several of the old temporary contracting dikes were repaired and new ones built, with a view to removing the sand by the scour of the increased current produced. By October 6 the gauge at Barbres had fallen to 2 feet above zero and lower Old River had become impassable for the regular steamboats, though small lightdraft boats continue to go through and transfer freight, between Barbres and Torra's Landing until October 30, when the water had reached two-tenths below zero. Navigation was suspended entirely from this date until November 27, when both the Red and the Mississippi rose rapidly and navigation was restored. During the period when navigation was suspended through Old River there were of course difficulties in many other places and through boats could not have safely loaded deeper than 5 feet for any portion of the Red and Atchafalaya system which remained navigable. Even at the extreme lowest stage, 1 foot below zero on Barbres gauge, lower Öld River at no point went entirely dry, as has always been the case heretofore; there being at the shoale st places a depth of not less than 1 foot. During the low water the small snag-boat Florence, which was loaned for the purpose through the courtesy of Capt. J. H. Willard, Corps of Engineers, U. S. A., did excellent work in lower Old River, clearing out snags and logs and the series of piling and old temporary dikes that had previously been constructed in attempts to maintain a low-water channel. From soundings taken during the lowest stage it was ascertained that to secure a channel throughout Old River from the Mississippi to the deep water near Barbre Landing, with a depth of 5 feet below zero and a bottom width of 75 feet, would have required the removal of only 75,000 cubic yards and had a dredge capable of working during low water in sand, stiff clay, and soft mud been available, this could easily have been effected, even with a plant of moderate capacity. It is at least encouraging to note the apparent improvement in the channel of lower Old River. This channel was very much better last fall than it has ever been before at corresponding stages. In only one instance during the period of four years covered by the records of Barbre gauge in this office has the water been lower than it was in 1891. In 1887 the gauge went down to 1.5 feet below zero, and lower Old River went entirely dry. It has frequently been closed completely when the lowest stage was considerably above the zero of the gauge. The favorable state of affairs last fall may have been partially due to accidental causes, which resulted in maintaining such relative height between the Mississippi and the Red and Atchafalaya rivers during the falling stages as to produce a defined current through lower Old River for a long period and so prevent the deposit of sediment, but it is also believed to be attributable to a material extent to influences which are now permanent or favorably progressive. These influences are the improved condition of the Tensas Basin levee system, which has lessened the escape of the crevasse waters from the Mississippi into the Red and Atchafalaya system above Bougere during floods; the growth of trees and the increased deposits on the bars in lower Old River, tending to narrow the channel, which has a tendency to diminish the caving and the trouble resulting from the forcing up of clay lumps and ridges in the bottom of the channel; and possibly the natural filling up of upper Old River, which would have the effect of increasing the flow through the lower Old River when the conditions are favorable to such flow. The continuation of the levee system south of Bougere, its present terminus, is a matter which should receive early consideration in connection with the improvement of navigation through Old River. In high water the Mississippi now flows over the western bank and into the basin of the lower Red for the entire distance of 7 miles between Bougere and Union Point, carrying in a large amount of sediment and tending to maintain a condition of equilibrium between the stages of the Lower Red and of the Mississippi and thus to neutralize the current through Old River and hasten the progress of filling up. There are also several smaller gaps between Union Point and the mouth of Red River through which there is a large escape in extreme high water. The Atchafalaya sill dams are still in good condition and no repairs were necessary during the year. The levee between the dams on the right bank had shown weakness during high water of 1891, requiring some work to stop holes and repair damage caused by sloughing. After the water went down the repairs were completed and a public road crossing constructed over the levee. When the work was first started a site was leased and depot and store houses established opposite Simmesport. This was convenient to the Atchafalaya sill dams, but too far from the principal part of the work during the construction of the Red River dam and dredging operations in Old Rivers. A new site near Barbres Landing was therefore leased and the storehouses and property moved to it during December and January. The telephone line was completed during September and has proved of very great value, particularly in the high-water season. Extensive repairs to six of the large barges and to the steamer Ruby, besides minor repairs to other portions of the plant, were made during the year. Nearly all of the plant was employed on the work at Plaquemine and on levee duty when not needed at Turnbull Island. The dredge Menge was returned to the Third District in February, being required at Vicksburg and no longer available in Old River until the low-water season. The dredge Pah Ute and the tug Comstock were taken to New Orleans for repairs, which are now in progress, and all other parts of the floating plant were removed to New Orleans, where it can be cared for with greater economy. In June 2,532 tons of rock were borrowed from that stored on Turnbull Island for use on the New Orleans Harbor work, and a like amount was returned to Turnbull Island during April, 1892, the expense of quarrying and delivering having been paid out of the allotment for New Orleans Harbor. Observations were taken to determine both the extreme low-water and the extreme high-water discharges of the Mississippi at Red River Landing, and of the Atchafalaya at Simmesport. The low-water discharge at and immediately below the Red River dam was also measured. During the extreme low water a careful survey was made to determine the condition of the Red River dam, and of the river bottom above and below. The field work was under the immediate charge of Assistant Engineer W. G. Price until September 20, when he was placed in charge of the work at Plaquemine and was relieved by Assistant Engineer G. Ed. Mott, who remained in charge until field work was closed for the season on February 12. The gauge at Simmesport, which was established in connection with the work on the Atchafalaya sill dams, was discontinued on May 15. Under direction of the Commission the officer in charge has visited and examined during the year most of the largest dredging plants in the United States and corresponded with a number of persons owning, operating, or manufacturing large dredging apparatus in this country and abroad. It having been decided to procure a dredging plant of the largest capacity practicable and of the most approved pattern for the work of opening Old River, specifications were prepared and advertisements for proposals issued on June 1, 1892, bids to be opened August 1. RED AND ATCHAFALAYA RIVERS. Money statement. July 1, 1891, balance unexpended..... May 8, 1892, transferred from Vicksburg Harbor.. May 4, 1892, transferred to New Orleans Harbor...... May 31, 1892, expended during fiscal year to date.................. May 31, 1892, balance available............. $147, 109. 28. 3,000.00 8,000.00 142, 109.28 $52,241.70 4. 15 52, 237.55 89, 871.73 Amount that can be profitably expended during fiscal year ending June 30, 1894..... 90,000.00 128.27 89, 871. 73 350,000.00 Assistant Engineer Mott's report covering the field operations for the year is as follows: MERRICK, LA., March 1, 1892. SIR: I have the honor to submit the following report on the work of improvement at the junction of the Mississippi, Red, and Atchafalaya rivers from June 1, 1891, to February 29, 1892. The conditions existing on the former date were as follows: Upon the sill for the Red River Dam two full courses of crib mats and a portion of a third course had been sunk and well ballasted with rock, 54,000 square feet of mats, sufficient to complete the third course, were on hand awaiting a stage of water when it would be safe to sink them, the lowest point of the crest of the dam was 7 feet below Barbre's zero, and there was a mean depth of 5 feet below zero for a width of 96 feet. Constant dredging in lower Old River had greatly improved the channel, while the considerable amount of dredging done in upper Old River had proved of little or no benefit; the route for the canal from upper Old River through Carrs Point to the Mississippi River had been surveyed, partially cleared, and some slight dredging done at the Old River end. The plant was in laying up quarters at the head of Turnbull Island and was in good condition with the exception of the barges which were undergoing repairs. A telephone line between West Melville, on the Texas and Pacific Railroad, and the head of the Atchafalaya River was in course of construction. Red River Dam.-The eight mats (51,500 square feet) which remained on hand from last season were sunk as the third course on the dam in the latter part of June; the shore end began at a point 20 feet on Barbres gauge on the Turnbull Island side and stretched out on the dam 496 feet, being ballasted with 927 tons of rock; this course overlaid the other two courses and the small part of the third course which had been sunk the previous fall, and raised a portion of the crest of the dam to 3 feet on Barbres gauge; there was, however, a low place near the center about 120 feet wide, the lowest point of which was 3 feet below Barbres zero; the eastern end of the mats was placed well up on the bank to sustain it and prevent sloughing. The remaining mat (2,480 square feet) was sunk above the upper edge of the dam on the left bank as a shore protection to prevent caving. There were cut and delivered in June and July 907 cords of willows, from which were constructed eight crib mats 68 by 80 by 3 feet; these were sunk in August on the western end of the dam, the shore end beginning at a point 20 feet on Barbre gauge and reaching out 544 feet on the dam; they were ballasted with 732 tons of rock; there was a gap of 90 feet between the river ends of this course and the third course, which had been sunk from the left bank; these courses were composed of mats 68 feet wide, wired together, and were sunk as one continuous mat across the current; this work was completed on August 10. An order was received on September 1 to remove a section of the upper course of mats in the center of the river for a distance of 300 feet in order to give a low-water channel of that width and 5 feet below Barbre zero; an attempt was made to blow out the section with dynamite, a large quantity being used, but charges of 100 pounds produced no effect other than to settle the work more compactly; a heavy anchor was then dragged over the section from the upper to the lower side of the dam, which had the desired effect, but the method was slow; a dredge fitted with a Hayward bucket was finally procured and the cut easily made. A section 260 feet wide and 4 feet deep, containing 83,200 cubic feet of material, was removed (the upper course only being cut away) and gave a channel 5 feet below Barbres zero; the willows floated away and the rock ballast was spread on the apron below; through this opening boats had no difficulty in passing until the water had fallen to 24 feet on Barbre gauge; at lower stages the dredge Menge, which had been previously located in mid stream above the dam, pulled several boats over without difficulty; at the lowest stage of the river, 1 foot below Barbre zero, Old River was entirely closed and boats could not reach the dam, but could have passed over it with the assistance of the dredge even at that low stage. In December the remaining portion of the west end of the third course of mats, a small section containing 19,200 cubic feet, was removed by dredging and there is now an opening over the center of the dam 450 feet wide, almost all of which has a depth of 5 feet below Barbre zero. About one-fourth of the third course of mats remains intact on the eastern end of the dam. Upper Old River.-The dredge Pah-Ute began work in upper Old River on June 5, the dredged material being deposited at one side of the cut, and on the 21st, the depth of water being too great, the dredge was removed and laid up at the head of Turnbull Island, 18,921 cubic yards having been excavated. On June 9 the dredge Menge was put to work, and by the 18th of July had removed and deposited on one side of the cut 50,553 cubic yards of soft mud; the water then being too high, it was taken to the head of Turnbull Island and laid up. Both these dredges were in first-class condition, and during the time of their service did very cheap work. The semiliquid character of the deposit in the bottom of upper Old River, between the junction of the three chutes and the foot of Turnbull Island, is shown by the fact that when the bed of the river was dry no traces of the large amount of dredging which had been done could be discerned. Lower Old River.-On August 31 the dredge Menge began operations cleaning out the channel in lower Old River, between Ash Cabin and Dead Tree, depositing the material excavated on one side of the cut, and continued work until September 22, when the water became so shoal that the dredge was with difficulty removed and placed above the Red River Dam; 44,638 cubic yards of clay were removed during that period, and the work done was of great benefit during low water; the dredge Pah-Ute was at once substituted for the Menge, and succeeded until October 17 in keeping open the channel for light-draft boats even when the water was below the zero of Barbre gauge; 24,500 cubic yards of material were removed and a long line of channel kept open. The river near the Mississippi end had by this time become nearly closed with soft mud and sand, preventing the water from getting in Old River. The dredge was, therefore, moved to the second crossing on the 18th, and in three days' time a cut 2,000 feet long had been made towards the Mississippi, 2,600 cubic yards of semiliquid mud and sand was removed which, owing to its character, slid back almost as fast as it was cut out, and as the water still continued to fall the dredge was removed and laid up in the deep water at the foot of Turnbull Island; the dredge had been pushed to its utmost capacity, and had been at work for 30 days without the slightest cessation for repairs; the hull forward was leaking badly, and repairs were greatly needed. During this same period a cut was made through the sand bar at the mouth by a dredge fitted with a Hayward bucket, making a channel 6 feet deep and 40 feet wide; this dredge then continued on to the second crossing, and began digging to connect with the Pah- Ute, the conditions being the same as those affecting the Pah-Ute. The attempt was abandoned after 3 days' work, there being danger that the dredge would be caught and remain in Old River for a long period. The material removed by this latter dredge was 9,500 cubic yards, and it compared very unfavorably with both the Menge and Pah-Ute in economy and celerity and capacity for handling this kind of material. Barbre gauge at this time read three-tenths below zero During the latter part of September and first part of October steamboats ex |