Introduction
1-1. Purpose
The purpose of this manual is to present basic principles used in the design and construction of earth levees.
1-2. Applicability
This manual applies to all Corps of Engineers Divisions and Districts having responsibility for designing and constructing levees.
1-3. References
Appendix A contains a list of required and related publications pertaining to this manual. Unless otherwise noted, all references are available on interlibrary loan from the Research Library, ATTN: CEWES-IM-MI-R, U.S. Army Engineer Waterways Experiment Station, 3909 Halls Ferry Road, Vicksburg, MS 39180-6199.
1-4. Objective
The objective of this manual is to develop a guide for design and construction of levees. The manual is general in nature and not intended to supplant the judgment of the design engineer on a particular project.
1-5. General Considerations
a. General
(1) The term levee as used herein is defined as an embankment whose primary purpose is to furnish flood protection from seasonal high water and which is therefore subject to water loading for periods of only a few days or weeks a year. Embankments that are subject to water loading for prolonged periods (longer than normal flood protection requirements) or permanently should be designed in accordance with earth dam criteria rather than the levee criteria given herein.
(2) Even though levees are similar to small earth dams they differ from earth dams in the following important respects:
(a) a levee embankment may become saturated for only a short period of time beyond
the limit of capillary saturation,
(b) levee alignment is dictated primarily by flood protection requirements, which often results in construction on poor foundations, and
(c) borrow is generally obtained from shallow pits or from channels excavated adjacent to the levee, which produce fill material that is often heterogeneous and far from ideal. Selection of the levee section is often based on the properties of the poorest material that must be used.
(3) Numerous factors must be considered in levee design. These factors may vary from project to project, and no specific step-by step procedure covering details of a particular project can be established. However, it is possible to present general, logical steps based on successful past projects that can be followed in levee design and can be used as a base for developing more specific procedures for any particular project. Such a procedure is given in Table 1-1. Information for implementing this procedure is presented in subsequent chapters.
