Livin' large with levees: Lessons learned and lost

The use of levees for flood control has a long history in the United States in part because their relatively low construction costs and general effectiveness in protecting low-lying areas are politically expedient. Consequently, there are thousands of counties and communities relying on levees as their primary flood protection measure. However, levees can also promote floodplain development, placing more property at risk, and they have negative hydrological and environmental consequences. In addition, failures occur when design standards are exceeded or because of poor maintenance, leading to catastrophic losses. Recognizing these limitations, the Association of State Floodplain Managers has issued 25 recommendations regarding the use of levees, three of which are evaluated here in the context of Yuba County, California, a county that has experienced three major flood events in the last 25 years due to levee breaks. Faced with ongoing development pressures and suburban sprawl from Sacramento, Yuba County has permitted several new residential areas in the flood-prone land, in anticipation of levee certification. The county's levee strategy demonstrates the county is going beyond what is currently required for official certification of its levees. However, it is clear that additional measures need to be taken in order for the risk to be fully acknowledged and managed. © 2008 American Society of Civil Engineers.