Search Your County, State or Address to See Flood Zones, Understand Your Local Flood Risk, and Learn What to Do Before the Next Storm.
Find Your County’s Flood Zone
Search your county, state or address to see flood zones, understand your local flood risk, and learn what to do before the next storm.
Independent guide. Not a government agency. For official flood determinations, use the FEMA Map Service Center.
Every U.S. county can flood. A county flood zone map shows which areas have a higher chance of flooding and which rules, insurance requirements and warnings may apply to you. County Flooding brings flood zone maps, flood risk explanations, flood warnings and preparedness steps together in one place, so you do not have to hunt across dozens of government websites.
Start by finding your county. Then use the guides below to read your map correctly.
What You’ll Find on County Flooding
- County flood zone maps: Find the official FEMA map for your county and learn how to read it.
- Local flood risk: Understand what your flood zone means, and why risk does not stop at a map line.
- Flooding events and warnings: Learn the difference between a flood watch, warning and advisory, and what each asks you to do.
- Flood-prone areas: See what makes some places flood again and again, and how to check your own street.
- Preparedness and resources: Checklists, insurance basics and links to official help.
FEMA Flood Zones Explained
FEMA flood maps, called Flood Insurance Rate Maps (FIRMs), sort land into zones. Areas with a 1% or greater chance of flooding in any given year are considered high risk. FEMA also notes that this means at least a one-in-four chance of flooding during a 30-year mortgage.
| Zone | What it means | Risk level |
|---|---|---|
| A | High-risk area. Base flood elevation not determined | High |
| AE | High-risk area with detailed study. Base flood elevations shown | High |
| AH / AO | High-risk areas with shallow flooding (ponding or sheet flow) | High |
| VE / V | Coastal high-risk area with extra hazard from storm waves | High |
| X (shaded) | Moderate hazard, between the 1% and 0.2% (500-year) flood limits | Moderate |
| X (unshaded) | Minimal hazard, outside the 0.2% flood limit | Low to minimal |
| D | Flood hazard undetermined because the area has not been studied | Unknown |
Zones starting with A or V are called Special Flood Hazard Areas (SFHAs). If you have a federally backed mortgage on a home in one, flood insurance is generally required. Older maps may use zones such as B and C, which newer maps replace with shaded and unshaded X.
A low-risk zone is not a no-risk zone. There is no such thing as a place that cannot flood.
How to Find Your County Flood Zone Map
- Pick your county. Browse by state above.
- Open the official FEMA map. The FEMA Map Service Center is the official source for flood hazard maps used in insurance and lending. Enter your address to see your zone.
- Note your zone and map date. Write down the zone letter, any base flood elevation, and the effective date of the map.
- Check your county’s own floodplain viewer. Many counties publish additional floodplain or floodway maps with their own rules. These can differ from FEMA’s.
- Download a FIRMette if you need a record. A FIRMette is an official printable map section that lenders and insurers recognise.
- Call your floodplain administrator if something looks wrong. Every community in the National Flood Insurance Program has one.
Which Flood Map Should You Trust?
People often find several different “flood maps” for the same address. They answer different questions.
| Map type | Who makes it | What it tells you | Use it for |
|---|---|---|---|
| FEMA FIRM / flood zone map | FEMA | Insurance and lending flood zones | Insurance, mortgages, building rules |
| County floodplain map | County or local government | Local floodplain and floodway rules, often from detailed watershed studies | Permits, local development standards |
| Storm surge / evacuation zone map | State or county emergency management | Coastal surge risk and evacuation order | Hurricane planning |
| Forecast and inundation maps | NOAA / National Weather Service, USGS | Predicted or modeled river and coastal flooding | Real-time decisions during a flood event |
Rule of thumb: federal flood insurance requirements follow the FEMA FIRM, even when your county shows a different or larger floodplain.
Flood Risk Goes Beyond the Map
Flood maps are snapshots built from studies at a point in time. Real flooding does not always respect those lines.
- FEMA’s FloodSmart program reports that over a 20-year period, 99% of U.S. counties experienced a flood event.
- Over a ten-year span, nearly one-third of flood claims came from outside current high-risk areas.
- Some independent tools estimate property-level risk using different models and can disagree with FEMA zones. Treat a modeled score as a second opinion, not as the legal map.
Use the FEMA zone for insurance and lending, then ask a second question: how would water reach my property? Look at nearby creeks, storm drains, slopes, the coast and past flooding on your street.
County Flooding Alerts: Watch vs Warning
The National Weather Service uses a tiered alert system for flood events.
| Alert | What it means | What to do |
|---|---|---|
| Flood Watch | Conditions are favorable for flooding. It is possible, not certain | Get ready. Review your plan and monitor updates |
| Flood Advisory | Flooding is expected to be a nuisance but not serious enough for a warning | Be aware. Avoid flooded roads |
| Flood Warning | Flooding is happening or about to happen | Take action now |
| Flash Flood Warning | A sudden, dangerous flood is imminent or occurring | Move to higher ground immediately |
Vehicle safety: the National Weather Service says nearly half of flash flood deaths are vehicle-related. If water covers the road, turn around.
Alerts are issued for specific counties and areas, so check the National Weather Service office that covers your county.
Flood-Prone Areas: Why Some Places Flood Again and Again
Flooding tends to repeat where the same conditions repeat. Common causes include:
- Rivers and creeks that rise gradually after heavy or prolonged rain.
- Flash flooding in urban areas, canyons and washes where water runs off quickly.
- Coastal flooding from storm surge, high tides and heavy rain together.
- Poor drainage in low spots, underpasses and older neighborhoods.
- Dams and levees that reduce risk but do not remove it.
Check your own area: ask neighbors and long-time residents where water collects, contact your county’s floodplain administrator or emergency management office, and look at USGS flood information and NOAA flood forecast tools.
Flood Preparedness: Before, During and After
Before a flood
- Know your zone and your evacuation route.
- Keep important documents in a waterproof container and make digital copies.
- Move valuables and electronics above likely water levels.
- Review your insurance. Most standard homeowners policies do not cover flood damage [VERIFY AGAINST CURRENT POLICY LANGUAGE].
- Sign up for your county’s emergency alerts.
During a flood
- Move to higher ground. Do not wait for water to reach you.
- Never walk, swim or drive through floodwater.
- Follow local evacuation orders immediately.
- Stay away from downed power lines.
After a flood
- Wait for officials to say it is safe to return.
- Photograph damage before cleaning up.
- Contact your insurer promptly.
- Be cautious of contaminated water, mold and structural damage.
Flood Insurance Basics
Flood insurance is separate from standard homeowners coverage in most cases.
- NFIP policies are federally backed flood policies sold through participating insurers.
- Private flood insurance is also available in many areas.
- Required vs recommended: lenders generally require flood insurance on federally backed mortgages in high-risk zones. People outside those zones can still buy it, and many should consider it.
- Waiting periods usually apply, so buy before a storm is forecast.
- Rates depend on risk factors under FEMA’s Risk Rating 2.0, not only your zone letter.
When Flood Maps Change: LOMAs, LOMRs and Preliminary Maps
- Preliminary maps are proposed updates. They are not yet used for insurance rating.
- Effective maps are the current legal maps.
- Letter of Map Amendment (LOMA): can remove a property that was mapped into a high-risk zone by error.
- Letter of Map Revision (LOMR): officially changes mapped boundaries.
- LOMR-F: used when a structure is raised above the base flood elevation with fill.
- Elevation certificate: a surveyor’s document that records your building’s elevation. It is often needed for these requests and for insurance rating.
If you are buying a home, ask whether the map is under review.
Browse Flood Information by State
Each state page lists its counties with links to the official FEMA map, local floodplain viewers, emergency management contacts and recent flood alerts.
Browse Flood Information by State
Each state page lists its counties with links to the official FEMA map, local floodplain viewers, emergency management contacts and recent flood alerts.
Where Our Information Comes From
- FEMA Flood Map Service Center and National Flood Hazard Layer
- FloodSmart.gov (NFIP)
- NOAA and the National Weather Service
- USGS flood information and inundation mapping tools
- County and state floodplain management offices
Our method: we summarize and explain official data. We do not create regulatory flood zones, and we cannot determine your legal flood zone. Every county page shows a "last reviewed" date [ADD REAL DATA].
Why You Can Trust County Flooding
- Source-first. Key claims point to the official source so you can verify them.
- Clear about limits. We tell you when a question needs a floodplain administrator, an insurer or an engineer.
Frequently Asked Questions
How do I find my county's flood zone map?
Use the FEMA Map Service Center and enter your address to see your flood zone. Then check your county's own floodplain viewer, since some counties add local floodplain rules. You can also download a FIRMette, a printable official map section. County Flooding links to both for each county.
What flood zone am I in?
Search your address on FEMA's Flood Map Service Center. Your zone appears as a letter code such as A, AE, VE or X. Zones starting with A or V are high risk. X zones are moderate or minimal risk. Zone D means flood risk has not been determined.
What are the FEMA flood zones?
FEMA uses zones A, AE, AH, AO, AR and A99 for inland high-risk areas, and V and VE for coastal high-risk areas. Zone X marks moderate (shaded) or minimal (unshaded) risk. Zone D is undetermined. High-risk zones are called Special Flood Hazard Areas.
What does a 1% annual chance flood (100-year flood) mean?
It means a flood of that size has a 1% chance of happening in any given year. It does not mean one flood every 100 years. Over a 30-year mortgage, that adds up to at least a one-in-four chance, according to FEMA.
Is flood insurance required outside a high-risk flood zone?
Generally not. Lenders require it for federally backed mortgages in high-risk zones. But flooding happens outside those zones too. FloodSmart reports nearly a third of claims over ten years came from outside high-risk areas, so many owners outside them buy coverage anyway.
What is the difference between a flood watch and a flood warning?
A flood watch means conditions are favorable for flooding, so be prepared. A flood warning means flooding is happening or will happen soon, so act now. A flash flood warning is the most urgent: move to higher ground immediately.
How many U.S. counties have experienced flooding?
FloodSmart reports that 99% of U.S. counties experienced a flood event over a 20-year period. Flooding is not limited to coastal or river counties. Heavy rain, drainage problems and flash floods can affect almost any area.
How often do flood maps change?
There is no fixed schedule. FEMA and local communities update maps as new studies, development and terrain data become available. Maps move from preliminary to effective status. Ask your floodplain administrator whether a revision is underway.
Can I change my flood zone designation?
Sometimes. If your property was mapped into a high-risk zone in error, you can request a Letter of Map Amendment (LOMA). Other changes use a Letter of Map Revision (LOMR). You will usually need an elevation certificate and supporting survey data.
Is a county floodplain map the same as a FEMA flood zone map?
No. County floodplain maps come from local studies and may apply local building rules. FEMA flood zone maps determine federal flood insurance requirements. Both can show areas with a 1% annual chance of flooding, but they may not match exactly.