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Letters of Map Change (LOMC)

Letters of Map Amendment (LOMA), Letters of Map Revision (LOMR) and Letters of Map Revision Based on Fill (LOMR-F) are documents issued by FEMA that officially remove a property and/or structure from the floodplain for flood insurance purposes. They are collectively called Letters of Map Change (LOMC). To obtain a LOMC, the applicant must submit the required data for the property to FEMA. The required data may include surveys, maps, engineering studies, elevation certificates and aerial photography or other visual data. Some data may be obtained from local government offices (e.g., the city hall, county courthouse, etc.). In most cases, the applicant will need to hire a registered land surveyor to prepare an Elevation Certificate for the property. The length of FEMA’s review process is dependent on the complexity of the project.

LOMCs may be issued for a single structure/lot or multiple structures/lots. All LOMCs remove the flood insurance purchase requirement. A structure or lot removed from the floodplain by a LOMC is not subject to the requirements of the NFIP, but may still be subject to the requirements of the local floodplain ordinance.

Users should contact the FEMA Map Information Exchange at 1-877-336-2627 for questions related to Letters of Map Change submittals.

Letter of map amendment

A LOMA is typically a correction to a flood map and is issued based on better survey data showing that either a property’s natural lowest grade or the lowest grade adjacent to the structure is above the base flood elevation. A property owner will often request a LOMA after being informed by a lending institution that the property is believed to be within a floodplain. FEMA does not charge a fee for reviewing a LOMA.

Under certain circumstances, FEMA requires a Conditional Letter of Map Amendment (CLOMA). A CLOMA is FEMA's comment on whether a proposed project would be excluded from the floodplain as shown on the flood map. The letter becomes effective on the date sent. It does not revise an effective flood map, but indicates whether the project, if built as proposed, would or would not be removed from the floodplain by FEMA if later submitted as a request for a Letter of Map Amendment (LOMA). FEMA does charge a fee for reviewing a CLOMA.

Letter of map amendment – Out as shown

A LOMA-OAS is issued when an applicant provides convincing visual evidence that a structure is outside of the mapped floodplain. FEMA issues a LOMA-OAS when a structure is incorrectly determined to be in the floodplain. A survey is not required as part of a LOMA-OAS application. FEMA does not charge a fee for reviewing a LOMA-OAS.

For more information on how to complete a LOMA-OAS, contact DNR Floodplains.

Letter of map revision

A LOMR is a revision to a flood map based on technical engineering studies submitted by the applicant to FEMA. LOMRs are typically issued for complex or large-scale projects such as subdivisions, stream relocations and road/bridge projects. FEMA charges a fee for reviewing a LOMR application.

Under certain circumstances, FEMA requires a Conditional Letter of Map Revision (CLOMR). A CLOMR is FEMA's comment on a proposed project that would affect the hydrologic and/or hydraulic characteristics of a flooding source and thus result in the modification of the existing regulatory floodway or effective Base Flood Elevations (BFE). There is no appeal period. The letter becomes effective on the date sent. This letter does not revise an effective NFIP map, it indicates whether the project, if built as proposed, would or would not be removed. FEMA charges a fee for reviewing a CLOMR application.

Letter of map revision based on fill

Under federal regulations, a property can be removed from a mapped floodplain if it is filled to an elevation that is at or above the base flood elevation. A LOMR-F is concurrence from FEMA that the data submitted by the applicant meets this standard and waives the flood insurance purchase requirement. FEMA charges a fee for reviewing a LOMR-F application.

Under certain circumstances, FEMA requires a Conditional Letter of Map Revision Based on Fill. A CLOMR-F is FEMA's comment on whether a proposed project involving the placement of fill would exclude an area from the flood map. The letter becomes effective on the date sent. This letter does not revise an effective NFIP map, but indicates whether the project, if built as proposed, would or would not be removed from the floodplain by FEMA if later submitted as a request for a Letter of Map Revision Based on Fill (LOMR-F). FEMA charges a fee for reviewing a CLOMR-F application.

Under Wisconsin regulations, a property can only be removed from the floodplain if the building site is filled to the flood protection elevation, is contiguous to lands outside the floodplain and a land use permit for fill is obtained.

Unless a LOMR-F and a land use permit are obtained prior to the start of any construction on the property, state and federal regulations would still apply.

Community responsibilities

Communities are required to maintain copies of all Letters of Map Change (LOMC) issued by FEMA because they represent changes to the effective Flood Insurance Rate Map. LOMCs are usually filed with a community's floodplain zoning map and other related technical data.

Copies of LOMCs can be obtained from local building officials, zoning administrators or FEMA. Instructions and forms for LOMCs, Letters of Determination Review and Elevation Certificates can be downloaded from FEMA's website.