Local Government Flood Resources

Local officials should be aware of the resources available to help them protect their communities from flooding.

Flooding presents a serious risk to home owners and public infrastructure. It’s integral that local officials are aware of the resources available to help them protect their communities, such as the National Flood Insurance Program (NFIP) and No Adverse Impact (NAI) initiative, as well as how to address discrepancies in flood map designations. To view a list of NFIP resources for local officials, including publications and forms and information about regional offices, the Community Rating System (CRS), and more, visit the Federal Emergency Management Agency website.

FEMA Laws and Regulations and the NFIP

The National Flood Insurance Program (NFIP) regulations are updated annually and address issues such as community floodplain activities, land management, and more. To view current regulations, visit the FEMA website.

National Flood Insurance Program (NFIP) Tips

No Adverse Impact (NAI)

“No Adverse Impact” (NAI) is an initiative of the Association of State Floodplain Managers (ASFPM) and exists to promote cooperation among communities sharing a watershed so that the actions of one community do not adversely impact the flood risk of another.

Development activities which encroach on a floodway (adding fill, new construction, substantial improvements) are subject to “no-rise” requirements and are prohibited unless an engineer’s Hydrologic and Hydraulic analysis (H&H Study) demonstrates that there will be 0.000 rise to the Base Flood Elevation (BFE) after the activity occurs.

There are several ways to meet the “No-Rise Requirement”:

Ways to meet the “No-Rise” Requirement:

  • Do not develop in the floodway or floodway fringe.
  • Replace existing structures like bridge abutments with structures of the exact same size in the exact same locations.
  • Make sure development spans the floodway without touching it.
  • Demonstrate No-Rise through an H&H Study.

Development activities on the fringe of a floodway may cause a rise in the Base Flood Elevation. Municipalities are limited to a one-foot cumulative rise above BFE for ALL development (under review, existing, and anticipated). An H&H study must verify that rise from any new activities will not cause the BFE to go over the one-foot limit when considered with other projects that have been executed or are under consideration. If an activity will cause the BFE to rise at all, a LOMR and a CLOMR must also be submitted to FEMA.

Before any changes can be made to the boundaries of a floodway, the municipality must obtain a floodway revision from FEMA through the LOMR process.

Letters of Map Revision (LOMRs)

Letters of Map Revision (LOMR), a type of Letter of Map Change (LOMC), are revisions to an effective FIRM’s (flood insurance map’s) flood zones, delineations, and elevations by written letter. LOMRs allow FEMA to revise flood hazard information without physically printing a whole new map panel. To determine whether there’s currently a new flood map under revision for your municipality, please contact your area’s County Planning Office.

A Physical Map Revision (PMR) is an action which physically changes and re-issues a portion of the FIRM anywhere from a ½ panel up to six panels (not countywide). PMRs must be adopted by the affected municipalities.

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