FEMA Floodplain Compliance: No‑Rise, CLOMR & LOMR
Floodway no-rise certifications and FEMA map revisions for developers, engineers, and property owners across Florida, prepared to pass floodplain administrator and FEMA review.
| Station | Effective | Proposed | Change |
|---|---|---|---|
| 1960 | 24.38 | 24.38 | 0.00 |
| 1720 | 24.11 | 24.11 | 0.00 |
| 1480 | 23.86 | 23.86 | 0.00 |
| 1250 | 23.52 | 23.52 | 0.00 |
Which one do I need?
Floodplain paperwork comes with a lot of acronyms. Answer two or three questions and we'll point you to the right path.
Not sure where your site sits? Look up the address on FEMA's Flood Map Service Center, or send us the address and we'll check it for you.
No-Rise vs. CLOMR vs. LOMR
The three floodplain approvals for development projects, side by side.
| Approval | BEFORE CONSTRUCTIONNo-Rise CertificationFloodway encroachment analysis | BEFORE CONSTRUCTIONCLOMRConditional Letter of Map Revision | AFTER CONSTRUCTIONLOMRLetter of Map Revision |
|---|---|---|---|
| When you need it | Any development in a regulatory floodway: buildings, fill, bridges, culverts, or grading. | Before building a project that will change flood elevations, the floodway, or the flood zone. | After the project is built, or when new data changes the flood hazard, to update FEMA's map. |
| What it shows | The project causes no increase (0.00 ft) in the base flood elevation. | FEMA's comment on how the proposed project would revise the flood map. | The official revision to the flood map, based on as-built conditions. |
| Who reviews it | Your local floodplain administrator | FEMA, after your community signs off | FEMA, after your community signs off |
| Review time | Set by your community | Up to 90 days once FEMA has a complete submittal | Up to 90 days once FEMA has a complete submittal |
| What we deliver | Signed certification, technical report, and effective and proposed model files | FEMA MT-2 application, hydraulic analysis, and revised work maps | FEMA MT-2 application, as-built analysis, and revised flood mapping |
- When you need it
- Any development in a regulatory floodway: buildings, fill, bridges, culverts, or grading.
- Who reviews it
- Your local floodplain administrator
- What we deliver
- Signed certification, technical report, and model files
- When you need it
- Before building a project that will change flood elevations, the floodway, or the flood zone.
- Who reviews it
- FEMA, after your community signs off. Up to 90 days once complete.
- What we deliver
- FEMA MT-2 application, hydraulic analysis, and revised work maps
- When you need it
- After the project is built, or when new data changes the flood hazard.
- Who reviews it
- FEMA, after your community signs off. Up to 90 days once complete.
- What we deliver
- FEMA MT-2 application, as-built analysis, and revised flood mapping
Removing a property from the flood zone: LOMA & LOMR-F
If FEMA's map shows your lot or building in the flood zone but it sits above the base flood elevation, you can apply to have it removed. That can lift the federal flood insurance requirement, though your lender may still require coverage.
Letter of Map Amendment, for property on natural ground above the base flood elevation.
Reviewed by FEMA, up to 60 days once completeLetter of Map Revision based on Fill, for property raised above the base flood elevation with fill.
Reviewed by FEMA with community acknowledgment, up to 60 days once completeFEMA review times per 44 CFR 72.4. Local review times vary by community.
Where we've worked
Based in Tampa, we take FEMA floodplain work anywhere in Florida. Here's where our recent projects have been.
- Broward
- Charlotte
- Clay
- Collier
- Hardee
- Hendry
- Hernando
- Highlands
- Hillsborough
- Lee
- Manatee
- Miami-Dade
- Monroe
- Palm Beach
- Pasco
- Pinellas
- Polk
- Volusia
What we need to get started
- Site address or parcel ID
- Site plan or survey, if you have one
- Proposed grading or structures
- Comments from the floodplain administrator
Only have an address? That's enough to start.
How a no-rise certification is built
We follow FEMA's model sequence, so the floodplain administrator can trace every result back to the effective study.
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STEP 1
Obtain the effective model
From FEMA's engineering library or the county floodplain office. We request it on day one, since it usually sets the schedule.
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STEP 2
Duplicate effective
Re-run FEMA's model to reproduce the published flood elevations. Legacy HEC-2 models are converted to HEC-RAS and datums to NAVD88 when needed.
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STEP 3
Corrected effective
Add cross sections at the project site and fix any errors, without changing the effective results.
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STEP 4
Existing conditions
Update the model to today's ground, from lidar or survey, including development built since the study.
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STEP 5
Proposed conditions
Add the project: fill, buildings, grading, or crossings. Then compare flood elevations with existing conditions at every cross section.
cross section
The certification. When proposed and existing flood elevations match, we prepare the no-rise certification, signed and sealed by a Florida Professional Engineer, with the report and model files for review.
Get a no-rise quote →Floodplain compliance questions
The questions we hear most from developers, engineers, and property owners. Don't see yours?
Ask us directly →What is a no-rise certification?
It's an engineer's certification, backed by a hydraulic analysis, that a project in a regulatory floodway won't increase the base (100-year) flood elevation. Federal floodplain rules require it before your community can permit development in a floodway, and your local floodplain administrator reviews it.
How long does a no-rise certification take?
Most of the schedule depends on getting the effective model, the hydraulic model behind FEMA's flood map. We request it from FEMA or the county on day one. Once we have it and have reviewed your site, we'll give you a firm timeline.
What if my project causes a rise in flood elevations?
There are two paths. The design can often be adjusted, for example by restoring conveyance elsewhere on the site, until the analysis shows no rise. If a rise can't be avoided, you'll need a CLOMR from FEMA before construction, which also requires notifying affected property owners and your community's approval.
What's the difference between a CLOMR and a LOMR?
A CLOMR (Conditional Letter of Map Revision) is FEMA's review of a proposed project before it's built. A LOMR (Letter of Map Revision) officially updates the flood map after construction, based on as-built conditions. Projects that change flood elevations usually need both.
What's the difference between a LOMA and a LOMR-F?
Both remove a property from the flood zone on FEMA's map. A LOMA (Letter of Map Amendment) is for property on natural ground above the base flood elevation. A LOMR-F (Letter of Map Revision based on Fill) is for property raised above it with fill.
Will a LOMA remove my flood insurance requirement?
It can remove the federal requirement to carry flood insurance on a mortgage. Your lender may still require coverage, and properties just outside the flood zone can still flood, so it's worth weighing a lower-cost policy.
Who reviews and approves these?
Your local floodplain administrator reviews no-rise certifications. FEMA reviews CLOMRs, LOMRs, LOMAs, and LOMR-Fs, and for most of these your community signs off first.
Do you work outside the Tampa Bay area?
Yes. We're based in Tampa and take FEMA floodplain work in all 67 Florida counties.
What do you need from me to get started?
An address or parcel ID is enough to start. A site plan, survey, proposed grading, and any comments from your floodplain administrator help us scope the work faster. Send us your project.