(A) General. The following sections describe the FEMA National Flood Insurance Program (NFIP) as it relates to FEMA floodplain management within the town. The following are references to FEMA documents that contain information pertinent to understanding the NFIP and for requesting revisions to existing defined FEMA flood hazard zones:
Appeals, Revisions, and Amendments to Flood Insurance Maps - A Guide for Community Officials (December, 2009)
Flood Insurance Study Guidelines and Specifications for Study Contractors (January, 2007).
A Unified National Program for Floodplain Management (January, 1994).
National Flood Insurance Program Website
(B) Federal Flood Insurance Rate Maps.
(1) In 1968 the U.S. Congress established the NFIP, which enables property owners within participating communities to purchase flood insurance at reasonable rates. The flood-hazard areas identified as Special Flood Hazard Areas (SFHA) have been delineated on Flood Insurance Rate Maps (FIRMs) which are available from the Public Works Department. These maps depict 100-year flood boundaries, flood insurance rate zones, and FEMA regulatory flood elevations, most of which are the result of detailed engineering analyses performed as part of a Flood Insurance Study (FIS).
(2) FIRMS are used by FEMA for establishing flood-insurance rates for affected structures, and by the FEMA and the town for floodplain management. All new development within FEMA regulatory floodplains must be reviewed and approved by the Public Works Department. During the review process the Public Works Department may require a more detailed analysis than was presented in the FIS. For smaller developments the FIRMs may be used to establish minimum finished floor elevations, or other site grade elevations.
(C) Map amendments and revisions.
(1) Occasionally, because of limitations of the scale at which a NFIP map was prepared, the floodplain boundaries are not delineated in sufficient detail to reflect individual structures that are elevated on relatively high ground, or show small parcels of land that have been filled. Similarly, floodplain information is subject to change, such as after the construction of drainage improvements or development of more accurate hydrology methods. Since FIRMs are subject to change because of a variety of reasons, FEMA has developed a map modification process designed to keep maps updated with current information.
(2) Information depicted on effective NFIP maps may be changed by a physical revision of the map, by a Letter of Map Revision (LOMR), or by a Letter of Map Amendment (LOMA). New map panels may be printed; or, if the revisions are relatively small, a LOMR/LOMA may be issued that describes the modifications. Changes to effective FIRMs resulting from the exclusion of individual structures and undeveloped parcels are described in a LOMA; whereas, communities having updated data, or having constructed new flood-control improvements may request a LOMR.
(3) The general requirements for technical and scientific data needed to substantiate a LOMR or LOMA are similar. However, there are procedural differences that determine the amount of data required, and how the data are to be submitted. General descriptions of the FIRM modification process are presented within the FEMA publication entitled Appeals, Revisions, and Amendments to Flood Insurance Rate Maps: A Guide For Community Officials. More technical information is included within the FEMA publication entitled Flood Insurance Study Guidelines and Specifications for Study Contractors. FEMA also publishes standard forms for presenting technical data for LOMA's and LOMR's. In addition, all map amendments and revisions proposed within the town are required to be reviewed and approved by the Arizona Department of Water Resources (ADWR). The engineer that is engaged in the process of performing map revisions within the town should contact ADWR to obtain current standards and criteria for performing such flood studies. If construction is proposed on land within a SFHA, a Conditional LOMA or LOMR can be obtained, provided that the proposed structural information meets the established criteria for a standard LOMA or LOMR. After construction is completed, certified "as-built" information must be provided to FEMA for the purpose of obtaining a LOMA or LOMR. The information required for a Conditional LOMA or LOMR is basically the same information that is required for either a LOMA or LOMR. Property owners and developers should note that a Conditional LOMA or LOMR only provides a comment on the proposed plan, and does not amend the map or waive requirements to purchase flood insurance.
(4) FEMA typically charges fees for the review of requests for the various types of map amendments and revisions. These fees can range from a few hundred to a few thousand dollars, depending on the complexity of the request. Since these fees are modified periodically, engineers engaged in preparing such requests should contact FEMA to obtain a current fee schedule.
(Res. 1637, passed 2-28-02; Am. Res. 2871, passed 9-17-15; Am. Ord. 872, passed 9-17-15)