Even if levees are similar to earth dams, they differ from earth dams because:
- they may become saturated for only a short period of time;
- their alignment is dictated by flood protection requirements;
- borrow is generally obtained from channels excavated adjacent to the levee.
Therefore, foundation soils are often poor while fill material is often heterogeneous and far from ideal and so levee sections are selected depending on the properties of the poorest material used.
Conversely, embankments that are subject to water loading for prolonged time should be designed in accordance with earth dam criteria.
It is useful to note the similarities and differences between dams and levees so that proper use of more extensive information regarding dams is made.