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~ e ~ ~ ~ t c IX - DESCRIPTION OF PROPOSED STRUCTURES AND IMPROVEMENTS 9-01. General. The Las Animas Local Protection Project would con- sist essentially of a levee 9.34 miles in length along the right bank of the Arkansas River and a levee 1.03 miles long on the left bank. The levees are designed to convey flows up to 140,000 c.f.s. with a minimum of 4 feet of freeboard. Appurtenant works would include levee protective measures; interior drainage facilities; a railroad grade raise and bridge alterations, and a sewage lift station. Relocation of local roads, improvements and utilities would be required. 9-02. The design of structures was based on applicable criteria set forth in Corps of Engineers' Engineering Manuals for Civil Works, and practices approved for similar projects. Detailed investigations were made in order to establish the most economical and suitable type of structures and provide a basis for a reliable estimate of project cost. The principal structures and improve- ments to be constructed are shown on pertinent plates and are described in the following paragraphs. A general plan of the improvements is shown on plates 1, 2 and 3. The necessary relocations involved are discussed in detail in SECTION XII - RELOCATIONS. The principal items of relocation would be alterations of the railroad bridge on the Arkansas Valley Branch Line of the A.T. & S.F. Railway across the Arkansas River northeast of Las Animas and a grade raise on the main line west of Las Animas. Since the existing bridge is inadequate to pass the design flood flows, it would be lengthened and raised to provide an adequate waterway. 9-03. Levees. A total of about 54,735 feet of levees would be required along the north and south banks of the river. The north bank levee would have an average height of 14.5 feet with a maximum of 17 feet and a total length of 5,435 feet. The south levee would average 13 feet in height with a maximum of 20.5 feet and a total length of 49,300 feet. The levees would consist of a compacted random fill section with crest width of 12 feet and side slopes of 1 on 3 on the riverside and 1 on 2.5 on the landside with a minimum freeboard of 4 feet above 140,000 c.f.s. design water surface. The plan and profile of the levees are shown on plates 4 through 17 and typical levee sections are shown on plate 18. Turnouts for wAintenance vehicles traveling on top of the levee would be provided at locations indicated on plates 4 through l4. 9-04. Borrow Areas. Approximately 90% of the random fill material required for construction of the levees would be obtained from borrow areas since the required excavation for other features would not suffice. It is anticipated that the required excavation for toe drains, drain ditches and that required to provide the necessary capacity for the ponding area right of ~he levee station 277+00 to 27