Free tool · FEMA flood map data
Am I in a flood zone?
Type an address to see its FEMA flood zone, whether it sits in the 100-year floodplain or a regulatory floodway, and the flood map panel behind it. Then see what that means for a retaining wall, fill, a patio or a permit.
Flood zones come live from FEMA’s National Flood Hazard Layer, the digital data behind the Flood Insurance Rate Maps. This is a planning check, not an official flood determination or an elevation certificate. Your address is not saved.
FEMA’s map service didn’t answer. Try again in a minute, or use FEMA’s Map Service Center.
Address search by OpenStreetMap Nominatim (data © OpenStreetMap contributors, ODbL). Flood data: FEMA National Flood Hazard Layer. A pin can land a few feet off; check the official map for a house right on a zone line.
| Type an address or use your location |
Walls, fill and other work in a stream or floodway also fall under DEP’s Chapter 105, and where FEMA hasn’t mapped a floodway, PA assumes it runs 50 feet from the top of each stream bank. See PA stream and creek permit rules, and use the PA building permit lookup to find your municipal office.
Planning information, not a survey or engineering. Call 811 and check with your local office.
What the zones mean
| Zone on the map | What FEMA means | For walls, fill and patios |
|---|---|---|
| A, AE, AH, AO, AR, A99 | Special Flood Hazard Area: flooded by the 1-percent-annual-chance (100-year, or base) flood | Permit for any development, including grading and fill. Elevations matter. |
| AE with floodway | The channel and nearby land kept open to carry the base flood | No fill or walls unless an engineering study shows no rise in flood levels (44 CFR 60.3(d)(3)). |
| V, VE | Coastal Special Flood Hazard Area | Coastal high-hazard rules; not found inland. |
| X (shaded) or B | Moderate hazard: between the 100-year and 500-year flood limits | Usually outside federal floodplain permit rules; some towns regulate it. |
| X (unshaded) or C | Minimal hazard: above the 500-year flood | Normal permits. Watch drainage anyway. |
| X behind a levee | Reduced risk due to a levee FEMA shows on the map | Normal permits; reduced risk is not zero. |
Zone definitions from FEMA’s flood zone glossary. Permit rules from 44 CFR 60.3, the floodplain standards every community in the National Flood Insurance Program has to adopt; your municipality can be stricter.
Why it matters for yard work
Raising the ground in a floodplain pushes water somewhere else. Where no floodway is designated, NFIP rules don’t allow new development, fill included, in Zones A1–30 and AE unless the combined effect raises the base flood no more than 1 foot (44 CFR 60.3(c)(10)).
A wall in a floodway is an encroachment. A wall elsewhere in the floodplain is development that needs a permit, and in PA a wall in or along a stream or floodway is a “water obstruction” under Chapter 105.
Keep on-grade patios at or below the existing ground in a floodway and send downspouts and drains away from the house. Ask the municipality’s floodplain administrator first; the township or borough office can tell you who that is.
Questions
How do I find out if my house is in a flood zone?
Type the address above. The tool finds the spot on FEMA’s National Flood Hazard Layer, the same digital flood map data behind FEMA’s Flood Insurance Rate Maps, and shows the zone, whether it is a Special Flood Hazard Area or a regulatory floodway, and the map panel and its effective date. For an official determination, use FEMA’s Map Service Center or ask your municipality’s floodplain administrator.
What is a 100-year flood zone?
FEMA calls it a Special Flood Hazard Area: land that will be flooded by a flood with a 1 percent chance of being equaled or exceeded in any given year, also called the base flood or 100-year flood. It is labeled Zone A, AE, AH, AO, AR, A99, V or VE on the map. Over a 30-year mortgage, a 1 percent yearly chance works out to about a 26 percent chance of at least one flood.
What does flood Zone X mean?
Zone X is outside the 100-year floodplain. Shaded Zone X (also shown as 0.2 percent annual chance) lies between the 100-year and 500-year flood limits and is a moderate hazard. Unshaded Zone X is minimal flood hazard. FEMA also uses Zone X for areas behind a levee it shows as reducing flood risk.
Can I build a retaining wall or add fill in a flood zone?
Not without a permit. Communities in the National Flood Insurance Program must require permits for construction and other development in their mapped flood zones, and inside a regulatory floodway they must prohibit fill and other encroachments unless an engineering analysis shows no increase in flood levels (44 CFR 60.3). In Pennsylvania, walls and fill in a stream or floodway also need a DEP Chapter 105 permit or waiver.
Can I put a patio in a flood zone?
Often yes, with a permit. Federal flood rules define development to include filling, grading, paving and excavation (44 CFR 59.1), so a patio counts. An on-grade patio that doesn’t raise the ground is usually simpler to approve than one built up on fill or held up by a wall. Ask your municipality’s floodplain administrator before you dig, and keep the finished grade at or below the existing grade in a floodway.
Does this tool save my address?
No. Everything runs in your browser. To find the spot, your address goes to OpenStreetMap’s Nominatim search, and the map point goes to FEMA’s public flood map service. We don’t store either one.
Sources: FEMA National Flood Hazard Layer (map service: Flood Hazard Zones layer 28, FIRM Panels layer 3); FEMA, Flood Zones glossary (SFHA = 1-percent-annual-chance flood; zone labels; Zone X shaded/unshaded); 44 CFR 60.3 (permits for development; no-rise rule in floodways (d)(3); 1-foot cumulative rule (c)(10)); 44 CFR 59.1 (development includes filling, grading, paving, excavation); 25 Pa. Code § 105.1 (floodway assumed 50 ft from top of bank where not mapped; water obstruction includes walls and fill); 25 Pa. Code § 105.11 (DEP permit required); OpenStreetMap Nominatim (address search, ODbL). Checked Nov. 12, 2026.
Muthler Landscaping & Construction · Lock Haven, PA
Wet yard or flood-zone project?
We grade yards, build retaining walls and put in French drains and dry wells across Clinton, Centre, Lycoming and Union counties. In a floodplain, we work from the approved permit and plan.
Get a quoteDrainage guideNot local? Groundwork Design Co. draws your wall or grading plan to scale so your floodplain office and contractor see the same thing.
Muthler Landscaping & Construction LLC · 913 Bellefonte Ave, Lock Haven, PA 17745 · (570) 397-9800 · PA HIC #PA212584.