Resources – Flood

Levee Education

Approximately 15,000 miles of levees exist in the United States. However, there is no one agency that inventories, owns or maintains all of these flood protection systems.

Residents may have difficulty identifying levee-impacted areas because many were built decades ago and form a familiar part of the landscape. Concerned citizens should consult city or county web sites or contact local government officials to learn more about their community.

Some levees are designed to provide year round protection due to the city's low elevation, but others furnish flood protection from seasonal high water and are subject to water loading for periods of only a few days or weeks a year.

In areas without recent flooding, there may be limited knowledge of the system. And levees may not be shown on FEMA Flood Insurance Rate Maps (FIRMs), as they are typically not considered to be in "Special Flood Hazard Areas" prone to regular flooding.

There is a common misconception that areas behind a levee system are outside the floodplain, but they are not. The areas they are designed to protect are at increased risk of flooding if the levee is overtopped or fails.

When this happens the results can be more damaging than if the levee were not there, due to increased elevation differences and water velocity. The water flowing through the breach continues to erode the levee and increase the size of the breach until it is repaired or water levels on the two sides of the levee have equalized.

• Levees are designed to protect against a particular flood level and may be overtopped in more severe events. 
• Levees require comprehensive maintenance programs, which become more of a challenge as the system gets older. 
• Levees involve significant planning and resources to be made ready for flood events. 
• Levees may fail to provide the level of protection for which they were designed.

Responsibility for Levees

Some levees are projects of the US Army Corps of Engineers. Others are built and owned by local people, towns or special districts created to operate and maintain the levee system. However, as the system ages, the effort required to maintain the levee's performance increases.

Some levee systems may not provide passive protection: sometimes action is required to ready levees for a flood event (“flood fight”). For example, roads and railroads passing through the levee often must be closed. If human intervention is required to make the system work, this requires advance planning, significant resources and allocation of responsibility for specific, timely actions.

• What areas are protected and what level of flooding is the levee system designed to control?
• What is the overall maintenance status of the levee system?
• What is your process to ready the levee for a "flood fight"? 
• What is the likely impact of the "flood fight" plan on the community?
• What areas are most likely to flood if the flood event exceeds the levee design and how much advance warning can be provided?
• Are maintenance funds are adequate, and if not, what steps are taken to ensure continued high-caliber maintenance?

Every local government with a levee system in its boundaries - and communities adjacent to a river with a levee system - should know what its risks are and prepare itself and its citizens to react if a failure does occur.

Citizens living in areas around or protected bylevees should take steps to minimize their home's risk of flooding. Most homeowners insurance policies do not cover property damage caused by the overflow or breach of levees, so it is strongly recommended that these residents have a flood insurance policy in place.

To learn more contact the National Flood Insurance Program or visit http://www.floodsmart.gov/.