Frequently Asked Questions
Answers to questions floodplain managers often have about mapping:
When the Federal Emergency Management Agency maps flood hazards in a community or county, two products are produced:
The study is a narrative report on a community's flood hazards. It has information on prior flooding, descriptions of flood sources, information about flood protection measures, and a desription of methods used.
The rate map illustrates the extent of flood hazards in a community. It displays flood risk zones and includes a special flood hazard area. It has base flood elevation information, flood depths, floodways, and physical features like roads.
Using both of these resources together, you can determine the floodplain development regulations for each flood risk zone. You also can see who must buy flood insurance.
The North American Vertical Datum of 1988 (NAVD 88).
Yes! Call the FEMA Map Assistance Center at 1-877-336-2627.
Included in federal flood maps, the Special Flood Hazard Area is the area that has a 1 percent greater chance of flooding in any given year. This area is known as the 100-year floodplain.
Locate a building or lot by consulting the Flood Insurance Rate Map, or contact the floodplain administrator of your community.
Yes! Development can take place with the Special Flood Hazard Area if it complies with local floodplain ordinances that meet criteria set by the National Flood Insurance Program.
Yes, this can be done by requesting a Letter of Map Amendment, known as a LOMA.
To successfully have an amendment issued that removes a structure from the hazard area, the lowest adjacent grade must be at our above base flood elevation.
Requestors must provide all information needed for review, which usually must include elevation information certified by a licensed surveyor if an elevation certificate isn't available.
There is no fee for the Federal Emergency Management Agency to review your request.
Before being approved and made effective, flood insurance rate mapsundergo a determination process which includes opportunities for public feedback from community officials and property owners. The process goes like this:
- Discovery
The Federal Emergency Management Agency conducts an assessment to determine if a new Flood Insurance Rate Map is required. If necessary, engineers will re-evaluate flood zones and develop a new map using Light Detection and Ranging technology and Geographic Information System.
- Flood Risk Review
A Flood Risk Review is conducted, and results are shared with the community through a presentation and an introduction of the draft map at a meeting. Feedback is collected.
- The Map Goes “Preliminary”
Using data and feedback, the new map is finalized. The effective date for the map is determined. Changes after this step will require formal appeals.
- Community Outreach Meeting
A community coordination outreach meeting is held to present local officials with the effective map, and to discuss the accompanying floodplain ordinance. A 90-day appeals window opens and the local government is given six months to formally adopt the floodplain ordinance.
- Public View
The public is invited to view effective maps and ask questions about the floodplain ordinance. The open-house meeting is optional and can occur before or after the Letter of Final Determination. This is a letter FEMA mails to the CEO of a community stating that a new map will become effective in six months.
Protests can be submitted during the appeal period. They can't address proposed base flood elevations. You need an appeal for that.
Protests can include, but are not limited to:
- Floodplain boundary deliniations based on more detailed topographic data
- Proposed regulatory floodway boundaries based on better modeling
- Requests that Letter of Map Amendments or Revisions Based on Fill be incorporated
- Base map errors
- Omissions
Appeals and protests must be supported by scientific or technical data, and provide proof of error sufficient data to make revisions.
Certification of data by a registered professional engineer or licensed land surveyor may be required.
Some flood studies result in new or revised base flood elevations.
During the 90-day appeal period, community officials and others can object to their accuracy.
Communities should coordinate with the Philadelphia office before submitting an appeal:
615 Chestnut St.
Sixth Floor
Philadelphia, PA 19106
215-931-5608
Appeals are submitted by mail to the Letter of Map Change Clearinghouse:
LOMC Clearinghouse
Attn: LOMA Manager
847 S. Pickett St.
Alexandria, VA 22304
For questions about forms, call the Map Information Exchange at 877-336-2627.
The Federal Emergency Management Agency issues a Letter of Final Determination and provides the community with six months to adopt up-to-date floodplain management ordinaces.
If the floodplain ordinances are satisfactory, they can be submitted in their current form.
If they need updated, communities should seek assistance from their state Flood Insurance Program Coordinator in the Philadelphia office:
615 Chestnut St.
Sixth Floor
Philadelphia, PA 19106
215-931-5608
After the six-month compliance period, the new flood study and flood map will become effective.
