Levees for Flood Protection

Levees were among the first river training structures built to protect human settlements and activities from floods. A levee is an embankment whose primary purpose is to furnish protection from high water due to river floods. Levees are similar to small earth dams, but there are important differences: — Levees are subject to high water levels only for a limited period of time (of the order of hours or rarely days), so that a levee embankment is generally not subject to saturation conditions. — Levee alignment is dictated primarily by flood protection requirements; this often results in construction on poor foundations. — Borrow is generally obtained from areas adjacent to the levee site, which produce fill material that is often far from ideal. Embankments that are subject to water loading for prolonged time periods or permanently should be designed using earth dam criteria.