Wisconsin
LOMA, LOMR-F and LOMR Flood Map Changes
Engineering and survey support to remove a property from a FEMA flood zone or revise a flood map.
What the work involves
A Letter of Map Amendment (LOMA) removes a structure or lot that is naturally above the base flood elevation, while a LOMR-F covers areas raised by fill, and a Letter of Map Revision (LOMR) changes flood hazard information based on new modeling or projects. LOMAs often need only survey elevation data, while LOMRs require hydraulic modeling by an engineer. FEMA charges no fee to review a LOMA but charges flat fees for most LOMR-F and conditional requests.
Local conditions we plan for
- Deep frost penetration
- Heavy snow loads
- Great Lakes shoreline erosion
- Karst in the southwest Driftless Area and Door County
Building code: IBC 2021 statewide for commercial buildings; one and two family dwellings use the state Uniform Dwelling Code instead of the IRC (ICC adoption chart, April 2026).
When you need it
- Lender requires flood insurance but the house sits on high ground
- Lot raised with fill (LOMR-F)
- Development or channel project changes the floodplain (CLOMR and LOMR)
- Flood map appears inaccurate for a property
Frequently asked questions
How much does lOMA, LOMR-F and LOMR Flood Map Changes cost?
Across the US, lOMA, LOMR-F and LOMR Flood Map Changes usually costs $500 to $50,000. Estimate. A simple LOMA can be a few hundred dollars of survey work plus no FEMA fee; FEMA's fee schedule lists single-lot LOMR-F reviews at $425 online and $525 paper. Full LOMRs with hydraulic modeling can cost tens of thousands of dollars.
How long does lOMA, LOMR-F and LOMR Flood Map Changes take?
Plan on LOMA: about 60 days of FEMA review after a complete submittal; LOMR: several months or more from signed proposal to stamped deliverables, longer if a site visit, soil testing or a permit review cycle is involved.
Do I need a licensed PE for lOMA, LOMR-F and LOMR Flood Map Changes?
In most US jurisdictions, yes. When the work needs a permit, the plans, calculations or report usually must be sealed by a Professional Engineer licensed in the state where the project is located. Every deliverable we issue for permit is sealed that way.
How do I verify an engineer's license in Wisconsin?
Engineers practicing in Wisconsin are licensed by the Wisconsin Examining Board of Architects, Landscape Architects, Professional Engineers, Designers and Professional Land Surveyors. You can confirm a license number and its status in the board's public license search before you sign a contract.
How deep is the frost line in Wisconsin?
Wisconsin Uniform Dwelling Code SPS 321.16 requires footings to be below frost penetration or at least 48 inches below adjacent grade, whichever is deeper (one and two family dwellings). Local building departments set the required footing depth, so confirm the exact figure for your county before designing foundations or retaining walls.
Which building code applies in Wisconsin?
IBC 2021 statewide for commercial buildings; one and two family dwellings use the state Uniform Dwelling Code instead of the IRC (ICC adoption chart, April 2026). Cities and counties can add local amendments, which is one reason to hire an engineer who works in your area.