Main Content

Final Levee Analysis and Mapping Approach

This page describes the Federal Emergency Management Agency's (FEMA's) approach to levee analysis and mapping flood hazards in the vicinity of levee systems. This page is for community officials and members interested in learning about FEMA's approach in managing non- accredited levee systems.

Final Levee Analysis and Mapping Procedure Released

FEMA released its Analysis and Mapping Procedures for Non-Accredited Levees. Non-accredited levee systems are levee systems that do not meet all the requirements outlined in Title 44 of the Code of Federal Regulations Section 65.10 along the entire length of the levee system. FEMA recognizes that levee systems that do not fully meet the requirements set forth in 44 CFR 65.10 may still provide a measure of flood risk reduction; for that reason, the agency has developed a suite of procedures for providing a more refined depiction of flood risks.

The Final Approach Document provides:

  • An synopsis of the agency’s historic analysis in the vicinity of levee systems,
  • An overview of the development process and teams responsible for procedure development,
  • Response to the public comments received and incorporated, and
  • An understanding of each analysis and mapping approach.

The adopted suite of procedures – Sound Reach, Freeboard Deficient, Overtopping, Structural-Based Inundation and Natural Valley  – has gone through an extensive process of scientific review and public input.  The suite of procedures outlined allows a levee system to be broken down into multiple reaches to allow the risks due to identified deficiencies to be better understood and determined.

Non-accredited levee system locations may be indicated on the Flood Insurance Rate Maps, however, the flood hazard on the landward side of the levee remains undetermined. FEMA will contact community officials and collect local input prior to determining the procedure(s) that will be used to identify the areas of potential flood hazard on the landward side of non-accredited levee systems.

The landward side flood risk will be determined through the use of the new levee analysis procedures. Once determined the procedures are used to analyze the flood risk in the vicinity of the non-accredited levees, the results will be identified on the FIRMs with one of two flood zone designations:

  • Special Flood Hazard Area (Zone VE, AE, A, AH, or AO), or
  • FEMA will indicate a possible flood hazard (Zone D)

Please note, Zone X designations may be used to indicate low to moderate flood risk on the landward side of accredited levee systems, to describe the area of flood risk reduction provided by the levee system, upon receipt of all required documentation identified in 44 CFR 65.10. Levee owners are still required to provide levee certification documentation as outlined in 44 CFR 65.10 for levee systems to be shown on the map as accredited.

The New Approach is Not...

  • A solution addressing all of the recommendations received from Levee Task Force, National Committee on Levee Safety or the National Research Council Levee Report
  • A holistic solution for all levee issues in the National Flood Insurance Program (NFIP)
  • A communication of the broad risks associated with levees and potential failures

FEMA has not made any regulatory changes to 44 CFR §65.10 during this process. Regulatory changes were not feasible given the time sensitivities for this effort. Levee owners will still be required to provide the documentation and certifications as outlined in 44 CFR § 65.10 for levees and levee systems to be shown on the map as accredited.

National Research Council Levee Report Released

FEMA commissioned the National Research Council (NRC) and its Water Science and Technology Board (WSTB) to examine the manner in which levees are addressed in the National Flood Insurance Program (NFIP).  The report, Levees and the NFIP: Improving Policies and Practices, identified some actions that FEMA may consider to improve the agency’s efficiency and effectiveness related to levees.

The report notes that “The Levee Analysis and Mapping Procedure is founded on sound algorithms with sound science and engineering behind them and follows established approaches to hydrology and hydraulics. It is a first cut at an approach to dealing with the hazards associated with levees that do not meet the standards for protection against the one percent annual chance flood.”

While LAMP for Non-accredited Levee Systems doesn’t achieve all of the goals and objectives outlined in the NRC report, it does make some important progress in achieving some of the actions identified. These new procedures allow FEMA to start piloting the identified approaches in a limited number of studies throughout the nation in agreement with the implementation procedure outlined in the report. These pilot projects will allow the agency to begin its engagement with local communities and levee owners utilizing the new procedures in a collaborative forum to foster a more precise understanding of flood risk in and around non-accredited levees.

Benefits of New Procedures

  • Improved models and tools that will provide more precise flood risk information behind non-accredited levees.
  • The ability to analyze the hazard associated with specific levee reaches, rather than the entire system. This will include identifying individual reaches that are fully compliant with FEMA's regulations for being accredited.
  • Increased flexibility with no one, broad procedure that will apply in all cases. Rather, FEMA will work with the local community to address their specific levee situation.
  • A more collaborative levee evaluation process that works with a Local Levee Partnership Team.

Local Levee Partnership Team (LLPT)

FEMA will coordinate with tribal, local community officials and levee owners to convene a LLPT when appropriate. The primary function of the LLPT will be to provide feedback, additional data and other input about the levee system in question. FEMA’s role will be to listen and gather the necessary information to effectively analyze and map the flood hazards in the area landward of the levee. The other partners will provide input on local conditions and situations.

This engagement will enable FEMA to make a better-informed final decision, using local input on how the levee system will be analyzed and how the flood hazards in the area landward of the levee will be mapped. There will be flexibility in how meeting(s) are executed including either in-person or by phone, depending on the complexity and need. FEMA or one of its representatives will participate and act as the group facilitator.

The makeup of the LLPT will be identified for invitation by FEMA in coordination with community and/or tribal officials. The following are examples of individuals who could be invited to participate in the LLPT:

  • Community CEO or designee (individual with decision-making authority - if not the CEO);
  • Community Floodplain Administrator (FPA);
  • Regional or State NFIP Coordinator;
  • Levee owner (if levee is not owned by community);
  • Local engineer/technical representative;
  • FEMA Regional Office representative;
  • USACE or other federal agency representatives that could provide additional input;
  • Cooperating Technical Partner (CTP), if a state or local department/agency overseeing map production in your community area;
  • Mapping partner/contractor that is supporting FEMA in the mapping effort; and/or
  • Others as determined by the community and FEMA Regional Office or CTP representative.

A fact sheet is avaliable containing more information on LLPT’s. This fact sheet also provides a detailed levee process workflow graphic depicting the various steps to analyzing accredited, provisionally accredited, and non-accredited levees and indicating frequency of stakeholder engagement activities.

Implementing the Levee Analysis and Mapping Procedure

In March 2013, the National Research Council of the National Academy of Sciences released a pre-publication version of the report Levees and the National Flood Insurance Program: Improving Policies and Practices (NAS Report). The NAS Report notes that the Levee Analysis and Mapping Procedures are founded on sound algorithms with sound science and engineering behind them and follows established approaches to hydrology and hydraulics. FEMA will implement LAMP in a manner consistent with the suggestions of the committee.

The steps for LAMP implementation are outlined below:

  1. FEMA will introduce the LAMP approach with a small number of pilot projects to understand the approach’s impacts, benefits, allowing the agency to consideration its broader implementation. The agency has always noted that it would roll-out LAMP in about 10% of the current on-hold studies, where communities were interested in moving forward with the LAMP solution.
  2. FEMA has been working since Mach 2011 to develop guidance for LAMP implementation on a national scale. The agency will engage with the pilot project communities to:
    1. Document the trial applications of LAMP,
    2. Refine the standards and guidance for implementation, and
    3. Prepare educational and training materials for future communities that will be engaged in LAMP.
  3. Implement LAMP on a larger scale across the nation. The agency is aware that the LAMP approach requires more interaction between FEMA and the local communities and is committed to understanding the local knowledge and operation of a levee system prior to its determination of the appropriate LAMP procedure(-s)


In order to pilot the Levee Analysis and Mapping Procedures, FEMA has reviewed all of the 280+ levee impacted projects to identify a set of projects to apply these procedures to.  In alignment with the implementation recommendations of the National Academy of Sciences, FEMA will apply these new procedures to a limited number of pilot projects

Approximately twenty-five (25) pilot projects were selected from across the nation based data availability which assisted FEMA in selecting projects to act as a cross-section of the new levee procedures. Additionally, on local interest in the application of these procedures as well as local input and investment in data collection to date assisted in the selection of these projects. Some of the projects selected included communities that were heavily involved in the public review process and a handful of the communities actively participated on the community round table sessions during the development of the approach. These pilot projects will begin during Fiscal Year 2013, and other future mapping projects will be prioritized as the projects are completed and additional funding is available.

Throughout the summer of 2013, FEMA Regional Offices will be in contact with the communities that have been selected as pilot projects to initially identify participants for a discussion about their local levee system and to determine members for a Local Levee Partnership Team.


July 12, 2013 – Final Approach Document released.

August 22, 2013 – Federal Insurance and Mitigation Administration (FIMA) Policy 204-078-1: Standards for Flood Risk Analysis and Mapping released.  This policy identifies the standards which must be followed in the delivery of the Risk MAP program.

September 2013Operational Guidance 12-13: Non-Accredited Levee Analysis and Mapping Guidance released.  Operating guidance documents are intended to support current FEMA standards and facilitate effective and efficient implementation of these standards.

The FEMA Regional Offices are working with pilot project communities to begin preparations to form the Local Levee Partnership Team for the identified levee systems.  Further investments in levee analysis and mapping will commence in following fiscal years.  Communities interested in applying the new levee analysis and mapping procedures to their levee systems should contact their local FEMA Regional Office for more information.

Important Consideration for Communities Affected by the New Procedures

FEMA has not made any regulatory changes to 44 CFR §65.10 during this process. Regulatory changes would not be feasible given the time sensitivities for this revised analysis and mapping effort. Levee owners will still be required to provide the documentation and certifications as outlined in 44 CFR § 65.10 for levees and levee systems to be shown on the map as accredited.

Non-Accredited Levee systems cause great concern for community elected officials, emergency management staff and federal agencies like FEMA due to the possible damage that could be realized due to failure of a portion or component of a levee system during a storm event, overtopping of a levee system or both.

The new approach will result in a change to the way FEMA analyzes areas on the landward side of non-accredited levees. However, FEMA cannot determine whether a community's Special Flood Hazard Area will increase or decrease based on the revised procedures until FEMA collaborates with the community and conducts the levee-specific analysis.

If a flood risk study in your community is impacted by non-accredited levees or levee systems, it likely has been placed on hold during development of the revised analysis and mapping procedures. For questions or comments about a study in your particular community, please contact your FEMA Regional Office.

As part of this collaborative process, FEMA will contact local community officials and levee owners to convene a Local Levee Partnership Team. This team will be organized to provide local understanding and input

Residual Flood Risk Must Still Be Mitigated

Although the analysis and modeling of levee-affected areas has been placed on hold, the flood risk that these levee systems were built to reduce still remains. No levee can completely eliminate flood risk. Living with levees is a shared responsibility and local community officials and communities as a whole should remain engaged in flood risk management activities. It's important for all to know the risk, know their role in helping to reduce that risk and what specific actions they can take, including the purchase of flood insurance to further reduce the financial risk associated with living and working in levee-affected areas.

Useful Resources

Different Roles, Shared Goals:

Federal, state and local agencies and departments share responsibility for flood risk management. Review the roles of each government level related to levees.

  • The USACE’s National Levee Database is a dynamic, searchable inventory of information about levees and a key resource supporting decisions and actions affecting levee safety. Review the National Levee Database to review information about the location and condition of levees and floodwalls, displayed in an easy-to-use map interface, as well as reports, inspection summaries and other records.

  • Federal agencies (FEMA, USACE and Bureau of Reclamation) continue to work together to align the nation’s federal levee processes and procedures. Review the progress these agencies have made on the recommendations provided by the National Committee on Levee Safety.

So You Live Behind a Levee.  A brochure developed collaboratively by the American Society of Civil Engineers containing basic information about levees and how to prepare for flood events.

Mapping Partners, Engineers & Technical Advisors:

Review the Final Approach Document to better understand FEMA’s approach to analyzing and mapping flood hazards in the vicinity of levee systems.

Related Links

For More Information

For more information about flood hazard or levee mapping and analysis information, contact a Map Specialist in the FEMA Map Information eXchange (FMIX) through the following methods:

  • Call (1-877) FEMA MAP (1-877-336-2627) Monday through Friday, 8:00 am through 6:30 pm (EST)
  • Email
  • Chat with a Map Specialist Monday through Friday, 9:00 am to 5:00 pm (EST)
  • Please subscribe to receive updates on FEMA Flood Hazard Mapping activities, including updates on levee-related activities, via e-mail.

Take Action!

Are you Ready? View maps of your area, assess potential losses, and Determine Your Risk.

Take action to Plan & Prepare for yourself, your family, and your community.

Learn more about Dam Safety and the Dam Safety Program.

Last Updated: 
01/11/2017 - 10:24