Recommendations for a National Levee Safety Program ...From the National Committee on Levee Safety

Frequently Asked Questions

Relationship to Other Federal Efforts

  1. Doesn't USACE already have a Levee Safety Program?
  2. What is the difference between the levee inventory USACE is conducting under WRDA 2007 and the NCLS recommendation for a levee inventory?
  3. If I live behind a levee accredited in the National Flood Insurance Program, I'm not at risk of flooding. Right?
  4. How do the recommendations of the National Levee Safety Commission relate to the updating of the Principles and Guidelines?

21. Doesn't USACE already have a Levee Safety Program?

The U.S. Army Corps of Engineers (USACE) does have a Levee Safety Program, but it does not have either the authority or the expertise to implement the comprehensive National Levee Safety Program recommended by the NCLS. The USACE Levee Safety Program, established in 1996, conducts inspections and assessments of approximately 14,000 miles of levee systems; evaluates, prioritizes, and justifies levee safety decisions; incorporates changes and improvements associated with state-of-the-art professional engineering practice into its levee safety policy and procedures; and makes recommendations to improve public safety associated with levee systems. The authorities of the USACE Levee Safety Program are generally limited to levees operated and maintained by USACE, federally authorized projects in the USACE Inspection of Completed Works program, and nonfederally authorized projects within the USACE Rehabilitation and Inspection Program.

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22. What is the difference between the levee inventory USACE is conducting under WRDA 2007 and the NCLS recommendation for a levee inventory?

The NCLS recommendations call for a one-time, federally funded inventory and inspection of all the nation's levees, with that data to be incorporated in the National Levee Database.

The levee inventory being undertaken by the U.S. Army Corps of Engineers (USACE), authorized by WRDA 2007 (the Water Resources Development Act), is of levees participating in the USACE Levee Safety Program, that is: levees operated and maintained by USACE; federally authorized projects in the USACE Inspection of Completed Works program; and nonfederally authorized projects within the USACE Rehabilitation and Inspection Program. This is an important first step in that many of these levees are large levees, with millions of people, property, and critical infrastructure behind them. However, it only includes approximately 14,000 miles of the estimated 100,000 miles of levees believed to exist in the nation.

Initially populated with data from its levee inventory, USACE is expanding the National Levee Database to include voluntarily submitted data from states in order to improve our understanding of the number, location, and condition of the nation's levees, a necessary step to fully understand our nation's risk.

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23. If I live behind a levee accredited in the National Flood Insurance Program, I'm not at risk of flooding. Right?

One of the biggest misunderstandings related to levees is that accreditation under the National Flood Insurance Program (NFIP) means that you are not at risk from flooding. In 1968, Congress enacted the NFIP with the primary purpose of addressing the inability of the public to secure privately backed insurance for economic losses due to flooding. The NFIP uses the protection level of a 1%-annual-chance flood (sometimes called the 100-year flood) as an actuarial standard. Homeowners living behind levees built to that standard are often exempted from the mandatory purchase requirements for flood insurance as a condition for a federally-backed mortgage, so many communities have built their levees to that standard and residents feel safe. The 1% annual chance level of flood protection is not a safety standard, however, and is frequently misinterpreted. Many believe this protection means that a destructive flood will occur on average only every 100 years. In reality, it means that there is a 1% chance every year that a flood of that magnitude will occur, translating to a 26% chance of flooding during a typical 30-year mortgage.

Unfortunately, the 1% annual chance, never intended to be a safety standard, became a design criterion for many communities and unrestricted development was allowed in leveed areas, greatly increasing the numbers of people and amount of property at risk from flooding.

Further, accreditation of a levee under the NFIP does not guarantee that the levee will not fail or overtop. Please consider: 1) storms and flooding exceeding the 1% annual chance can and do happen on a regular basis, additional development in the floodplains and stronger storms due to a changing climate further increase the chances of higher and more violent flooding; 2) many levees, even those well maintained, are aging and have not been updated to meet modern engineering standards; and 3) all levees can fail.

Bottom Line: The accreditation of levees under the National Flood Insurance Program merely ensures that the levee has met the technical standards for providing an expected level of flood protection. It does not guarantee that the levee will not be overtopped — and your home flooded — during a larger storm event, or that the levee cannot be damaged or breached unexpectedly. While living behind an accredited levee reduces your risk of flooding, it does not eliminate it. Flood insurance is one of the most effective ways to limit financial damages in the case of flooding, and speed the recovery of flood-damaged communities.

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24. How do the recommendations of the National Levee Safety Commission relate to the updating of the Principles and Guidelines?

Overall, the Administration's effort to update the Principles and Guidelines for Water and Land Related Resources Implementation Studies (known as "The Principles and Guidelines" or "P&G") — with its stated goal of better understanding costs and benefits of federal actions in a broader fashion, including social, environmental and public safety impacts, as well as economic benefits — is consistent with the recommendations of the NCLS for a National Levee Safety Program.

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Photo of Lupines on the levee.
Lupines on a Sacramento River levee in Sacramento, California.

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Test Your Levee IQ

What percentage of the approximately 15,000 miles of levees in US Army Corps of Engineers Levee Safety Program are operated and maintained by local sponsors?

  1. 10%
  2. 25%
  3. 65%
  4. 85%

Answers to this, and past, questions.