Levee Design and Construction

CE guidance for design and construction of flood control levees is contained in "Engineering and Design, Design and Construction of Levees" (US Army Corps of Engineers 1978). Levee design includes consideration of flow frequency, duration, and stages; erosion potential; seepage; soils; subsidence; maintenance and inspection requirements; and potential flood fight conditions. The guidance reflects the basic engineering considerations for design and construction of an earth embankment to retain water.

Aesthetics are of special concern from the standpoint of protecting the environment and blending levees with the surrounding environment. Vegetation on levees could serve purposes such as harmonizing a levee project with the surrounding environment, controlling dust and erosion, separating activities, providing privacy or screening of undesirable features, or providing habitat for wildlife. CE guidance on planting levees is contained in "Engineering and Design, Landscape Planting at Floodwalls, Levees and Embankment Dams" (US Army Corps of Engineers 1972) The guidance is to keep the basic levee structure free of roots and to provide a margin of safety of at least 1 m. (3 ft.) between the deepest expected penetration of plant roots and the face of the basic levee structure. If trees and shrubs are desired on a levee, the levee section must be overbuilt to accommodate the plant roots. This basic guidance is depicted in figure 1.

Figure 1.
Cross-sections of an urban levee showing:
a) root-free zone; b) overbuilt area; c) trees,
shrubs and grass cover; d) basic structure.