NO. 3.-FALLS OR RAPIDS AT FOOT OF SODA LAKE, LA., SEPTEMBER, 1911. NO. 4.-FALLS OR RAPIDS AT FOOT OF SODA LAKE, LA., SEPTEMBER, 1911. thing that leads me to believe that this cutting back of the falls need be given any serious consideration. In fact, the falls are only the rapids at the head of Twelvemile Bayou, where it leaves Soda Lake. 8. These falls are naturally working back into Soda Lake, thus reducing the slope in the upper part of Twelvemile Bayou, but the movement is slow, and there is yet about 11,400 feet of hard material to be cut through before Little Willow Pass is reached, and the rate of cutting will naturally decrease as the slope decreases. From borings made throughout the limits of Soda Lake in connection with this survey, the material in the bed of this lake appears to be the same as that at the falls. It will be a very long period before there need be any fear of injury to Caddo Lake from this source. To show the insignificance of these falls, attention is invited to the accompanying large scale map of the survey at the site of the falls and to four photographs taken in September, 1911. 9. In my opinion the problems of this waterway and of the surrounding country are those of reclamation and flood control, and I believe that the sooner the idea of water improvement with other than those ideas in mind is abandoned the better for the community. I believe also that this is the opinion of practically all of the interested parties in the community whose opinion is based on at least a general knowledge of the conditions. 10. I believe that the improvement of this waterway below Caddo Lake is being advanced principally by those interested in the benefits to be derived from the channel as a drainage canal and that the majority of those who acquiesce or offer no objection hold the same opinion. 11. Since it is considered by all interested parties that the improvement of the waterway below Caddo Lake will be beneficial from the standpoint of reclamation and flood control, the local interests, especially those interested in the drainage problems, should be willing to contribute to any project undertaken by the United States which will conform wholly or partially to their plans for flood control immediately above Shreveport. Attention is especially invited to that portion of the report on the preliminary examination which discusses the attitude of the drainage interests. 12. The only reasons of importance from the standpoint of navigation that have been advanced in behalf of the improvement of this waterway are those relating to possible reduction in freight rates and the benefits that would be derived to the community west of Shreveport due to such reduction. In my opinion those reasons should not be given undue weight for the following reasons: (a) There is no assurance that there will be any navigation on an improved waterway. The tributary country is sparsely settled, and but little of the available commerce will make use of the water way. (b) There is little or no prospect of new developments in this locality that will produce commerce for this waterway. (c) There is no navigation now on Red River to Shreveport, and there has been none for some years. It is doubtful if successful navigation is practicable on that river up to Shreveport. No navigation on Red River in the vicinity of Shreveport is to be anticipated for years. (d) If the present freight rates are too high it would seem that their reduction is a matter of regulation or legislation to that end by the proper authorities. 13. I have yet to find one sound reason for the improvement of any portion of this waterway in the interests of navigation alone. 14. In the preparation of a project for an all-the-year navigation from Red River to the dam at the foot of Caddo Lake it is assumed that a navigable depth of at least 4 feet should be provided, that the bottom width should be 75 feet, minimum radius 500 feet, and slopes 2 horizontal to 1 vertical. It is thought that no project that will not give continuous all-year navigation should be considered. 15. The low-water flow of this waterway is too small to provide any slope, and back water from Red River must be counted on to provide enough depth during the low-water seasons. The fluctuations of Red River are so frequent that only a channel that will insure continuous navigation should be provided. This necessitates a low-water surface corresponding with extreme low water in Red River, or 5 feet below the zero on the Weather Bureau gage at Shreveport. Hence to secure a 4-foot navigable channel a depth of 4 feet below the extreme low-water plane in Red River must be provided, and the estimates are based accordingly. In connection with the fluctuations of Red River attention is invited to the discussion on that subject by Mr. T. B. Warden, junior engineer, in his report; also to the profiles showing the gage readings at Shreveport from 1890 to 1911, inclusive, accompanying the maps of this survey. 16. The elevation of the water surface in the proposed channel to Caddo Lake is assumed at 156.30 feet Cairo datum. The water surface in Caddo Lake as provided by the dam now under construction is approximately 188.4 feet Cairo datum. A maximum lift at Caddo Dam of approximately 32.1 feet must therefore be provided. It is assumed that this lift can best be made with two locks of equal lift, and available dimensions of approximately 40 by 150 feet. 17. In preparing projects for this waterway two routes are considered: (a) A channel from the foot of Caddo Lake to Red River by way of Big Pass, Little Pass, Soda Lake, Twelvemile Bayou, Gilmers Ditch (Bonners Ditch) and Cross Bayou. (See project A and accompanying maps.) (b) A channel from the foot of Caddo Lake to Red River by way of Big Pass, Little Pass, Soda Lake, Twelvemile Bayou, Gilmers Ditch, and Old Channel of Twelvemile Bayou. (See project B and accompanying maps.) 18. In preparing estimates for this work, dredging is estimated at 12 cents per cubic yard, and the cost of locks is based on the experience of this office in connection with the construction of locks on Trinity River, Tex. 21. Project A is that which will best meet the needs of the local interests in the solution of their drainage and reclamation problems, for it will permit the extension of the west Red River levee to Cross Bayou, thus closing the present mouth of Twelvemile Bayou and reducing the flood height in the country to the west of this levee by the amount of the slope in Red River during flood stages between the present mouth of Twelvemile Bayou and Cross Bayou (possibly 4 or 5 feet). The new channel will also more satisfactorily care for the drainage of the country benefited, for it will extend in general along the trough of the area west of Red River, and by providing an outlet farther down Red River than at present will carry off more quickly the flood waters along the entire waterway. From a navigation standpoint there is little choice between projects A and B above. In my opinion project A meets more satisfactorily the general needs of navigation, flood control and drainage, and of the two it is the one that should be adopted. 22. Under project A a draw span will have to be placed in the bridge of the Texarkana, Shreveport & Natchez Railroad across Cross Bayou. As this bayou is a navigable waterway, that railroad should be required to provide a draw in its bridge. The city of Shreveport maintains a dam across the foot of Cross Bayou and a pipe line across the bayou. The dam will have to be removed and the pipe line submerged. It is understood that the city of Shreveport will cooperate to this extent. 23. Under project B a drawbridge will have to be constructed where the proposed channel crosses the Texarkana, Shreveport & Natchez Railroad. It is estimated that a suitable bridge at this site will cost approximately $140,000. MAINTENANCE. 24. One of the very uncertain points in connection with the question of maintenance of this proposed waterway is that of maintaining a channel in Red River from the mouth of Twelvemile Bayou, or from the mouth of Cross Bayou, to Shreveport, and no project that does not insure a channel to Shreveport should be considered. To provide a channel in Red River, dredging after every rise and fall will probably be necessary. This will necessitate the maintaining of a dredge available for use at that point whenever necessary. 25. The maintenance of the proposed channel will be large until the banks assume slopes that are normal for this waterway. After that time maintenance will be that due principally to deposits from back water from Red River, which should be confined principally to the lower portions of the channel. The period of excessive maintenance is estimated at one year following the completion of the work. Estimates are based on all work after the first year being done by a dredge owned by the United States. In my opinion, this dredge should be built out of the funds first appropriated, so that it may be utilized in connection with work on the project. The bulk of the work should be done under contract, the Government-owned dredge being simply used to facilitate the completion and to decrease the cost. 26. Maintenance for the first year: Operation of the dredge and locks... Contract excavation, 700,000 cubic yards, at 15 cents... $45,000 105,000 Total.... Provided the dredge has not been constructed out of funds appropriated for 150,000 125,000 Operation of the dredge, snagging operations, operation of locks, etc........ $50,000 CONTRIBUTION. 28. On account of the benefits to be derived by the local interests through the improvement of the drainage conditions, it is thought that they should contribute liberally to this improvement. In a letter dated April 19, 1912, the Caddo Levee Board of Caddo Parish, La., through its president, stated: We now feel able to pledge fifty to one hundred thousand dollars toward drainage. Owing to the benefits which will be received by, the locality from this improvement, in my opinion such a contribution is entirely inadequate. It is thought that the project is one that offers but little definite benefit to the United States or to the locality from a navigation standpoint, but much to the locality from the standpoint of flood control and drainage. The local interests should participate to the extent of at least 50 per cent of the total cost, or approximately $1,100,000. 29. The adoption of any project in connection with the improvement of this waterway should also be contingent upon the local interests furnishing all necessary rights of way. OTHER CONSIDERATIONS. 30. Though the survey does not contemplate the improvement of the waterway above the foot of Caddo Dam, yet the waterway above that dam, extending through Caddo Lake and up Cypress Bayou to Jefferson, is such an integral part of the waterway that it must be considered. The object of this survey is undoubtedly to consider the possibility of securing a navigable channel from Shreveport, La., to Jefferson, Tex., and if the waterway now being provided above Caddo Dam is inadequate, it will make the part under consideration equally so. 31. An examination of the map of Cypress Bayou shows that even with the improved conditions due to the construction of Caddo Lake Dam (now under contract) a considerable amount of work in the nature of cut-offs will be necessary to secure through Cypress Bayou a 4-foot navigable channel of equal capacity to that below Caddo Dam. It is estimated that it will cost $100,000 to secure such a |