FEMA Updates on “Without Levee” Analysis in New Flood Maps
In March 2011, FEMA agreed to end its policy of disregarding non-accredited levees and flood structures in the process of updating FIRMs. This “all or nothing” approach to evaluating levees and the flood risks behind them affects levee owners who cannot or will not develop technical data for FEMA accreditation of their levees.
New Rules Proposed, Now Being Finalized
FEMA has now proposed new rules for “Analysis and Mapping Procedures for Non-Accredited Levees.” These rules were provided for public review, and the comment period ended January 30. FEMA is now evaluating comments and finalizing the proposed rules.
No Change to 44CFR65.10 Requirements
The new rules do not change levee certification requirements as detailed in 44CFR65.10. The proposed rules will be applicable to non-accredited levees and provide technical approaches to developing FEMA flood maps and some credit for the presence of a levee, although not providing a fully protected flood area behind the levee on the FIRM.
Scenario-Based Zones = More Inundation Mapping Steps
A scenario-based levee protected zone for a non-accredited levee will incorporate more technical steps for flood inundation mapping. However, these additional steps will provide a more realistic evaluation as to where a levee may not be completely effective during the base flood but would still provide some level of flood protection. This new method of evaluation improves on the current FEMA mapping methodology that does not consider any portion of the levee to be in place, even if only one area of the levee is inadequate. By necessity, this new evaluation method will engage close coordination with the levee owner (community) and FEMA as provided in the proposed rules.
FNI Can Help
For levee owners evaluating the value of continuing to pursue FEMA levee accreditation, the incorporation of these modeling approaches may influence your decision. FNI can provide technical evaluation of levee issues, flood risks, and creative solutions in this ever-changing FEMA levee accreditation process.
For More Information
A thorough explanation of the proposed rules can be accessed on FEMA’s website.
FEMA has also provided a document that explaining the process, including the five technical mapping procedures: Revised Analysis and Mapping Procedures for Non-Accredited Levees: Proposed Approach for Public Review