Levee Protection and Accreditation
Which cities sit behind levees, and whether FEMA accredits them, from the USACE National Levee Database.
Last updated: August 2026
How Many Cities Are Protected by Levees?
Levee Systems
1,019
Distinct systems
Cities
319
With levee coverage
States
49
Of 50 + DC
Protected Area
22,236
Square miles
319 of the cities on this site sit behind at least one levee system, spread across 49 states. Levees are concentrated where large rivers meet dense development, which is why a handful of states account for most of the total.
Counts levee systems in the USACE National Levee Database whose listed communities match a city covered by FludZone. Systems protecting only unincorporated county land are not counted, so this is a floor on national levee coverage rather than a complete census.
Are These Levees FEMA-Accredited?
Mostly not. 542 of 1,019 systems (53%) are not accredited by FEMA, against 375 (37%) that are. Accreditation is a mapping decision rather than a structural verdict: it means a community has given FEMA enough documentation to show the levee on its flood maps as reducing the base flood risk.
Accredited
375
Shown on FIRMs as reducing risk
Provisional (PAL)
60
Documentation pending
Not Accredited
542
Area mapped as if unprotected
Unknown
42
No rating recorded
A non-accredited levee is not necessarily a failing one. Accreditation turns on paperwork submitted to FEMA under 44 CFR 65.10, and many communities never complete it. What it does change is the flood map: without accreditation, FEMA generally maps the area behind the levee as though the levee were not there.
All States Levee Data
| State | Systems | Cities | Accredited | Not Accredited |
|---|---|---|---|---|
| California | 325 | 50 | 51 | 235 |
| Texas | 67 | 22 | 46 | 19 |
| Louisiana | 45 | 18 | 20 | 20 |
| Kansas | 43 | 18 | 16 | 15 |
| Arizona | 41 | 10 | 25 | 11 |
| Washington | 41 | 14 | 8 | 33 |
| North Dakota | 38 | 8 | 10 | 25 |
| New Mexico | 31 | 5 | 8 | 21 |
| Ohio | 28 | 6 | 18 | 8 |
| Illinois | 27 | 14 | 4 | 21 |
| Colorado | 24 | 8 | 15 | 8 |
| Iowa | 24 | 6 | 16 | 4 |
| Nebraska | 20 | 5 | 3 | 14 |
| New York | 19 | 10 | 13 | 6 |
| Utah | 18 | 4 | 14 | 4 |
| Pennsylvania | 17 | 9 | 6 | 8 |
| Minnesota | 16 | 7 | 10 | 4 |
| Indiana | 15 | 9 | 9 | 6 |
| South Dakota | 15 | 4 | 8 | 4 |
| Missouri | 14 | 5 | 5 | 4 |
| Arkansas | 13 | 5 | 5 | 5 |
| Virginia | 11 | 6 | 5 | 6 |
| Oregon | 9 | 3 | 5 | 4 |
| Connecticut | 8 | 6 | 4 | 4 |
| Massachusetts | 8 | 4 | 7 | 1 |
| Mississippi | 8 | 4 | 2 | 4 |
| Montana | 8 | 3 | 5 | 2 |
| Nevada | 8 | 5 | 5 | 3 |
| Oklahoma | 8 | 5 | 4 | 4 |
| Florida | 7 | 5 | 1 | 6 |
| Idaho | 7 | 3 | 3 | 4 |
| Michigan | 7 | 3 | 1 | 6 |
| Alaska | 6 | 2 | 4 | 2 |
| Kentucky | 6 | 5 | 5 | 1 |
| North Carolina | 5 | 5 | 1 | 3 |
| Delaware | 4 | 1 | 0 | 4 |
| Tennessee | 4 | 2 | 2 | 1 |
| Wisconsin | 4 | 2 | 2 | 2 |
| Rhode Island | 3 | 3 | 3 | 0 |
| South Carolina | 3 | 2 | 0 | 3 |
| West Virginia | 3 | 2 | 2 | 0 |
| Wyoming | 3 | 2 | 1 | 2 |
| Georgia | 2 | 2 | 0 | 2 |
| Maryland | 2 | 2 | 0 | 2 |
| Alabama | 1 | 1 | 0 | 0 |
| Maine | 1 | 1 | 1 | 0 |
| New Hampshire | 1 | 1 | 1 | 0 |
| New Jersey | 1 | 1 | 0 | 1 |
| Vermont | 1 | 1 | 1 | 0 |
Source: USACE National Levee Database. Data sourced August 2026. Sorted by system count. State counts sum to 1,020 rather than the national 1,019 because one levee system protects cities in more than one state and is counted once nationally but once per state here.
Which States Have the Most Levee Systems?
Levee systems protecting at least one city, by state.
What Does a Levee Mean for Your Property?
A levee reduces flood risk. It does not remove it. Every levee is designed to hold back a specific flood level, and a larger flood can overtop or breach it - the risk that remains is called residual risk, and it is why living behind a levee is not the same as living outside the floodplain.
What accreditation changes is how your property is mapped. Behind an accredited levee, FEMA gives credit for the reduced risk and the area is often mapped outside the high-risk Special Flood Hazard Area, so flood insurance may not be federally required. Behind a non-accredited levee, the area is generally mapped as if the levee were absent, which can mean a high-risk designation and a mandatory insurance requirement on a federally backed mortgage.
To see whether a specific address sits behind a levee, look it up directly - levee systems are drawn on the map alongside the flood zone. For the regulatory detail behind accreditation, Zone AR and Zone A99, see the levees and dams guide.
Frequently Asked Questions
How many US cities are protected by levees?
319 of the cities FludZone covers sit behind at least one levee system, across 49 states. Those cities are protected by 1,019 distinct levee systems covering roughly 22,236 square miles. This counts levee systems in the USACE National Levee Database whose listed communities match a city on this site, so it is a floor rather than a complete national census.
Are most levees FEMA-accredited?
No. Of the 1,019 levee systems in this data, 375 (37%) are accredited by FEMA, while 542 (53%) are not, and 60 carry Provisionally Accredited Levee (PAL) status. Accreditation is a mapping decision, not a verdict on whether a levee is well built - it means FEMA has enough documentation to show the levee on flood maps as reducing the base flood risk.
Does living behind a levee mean I do not need flood insurance?
No. A levee reduces flood risk; it does not remove it. Even an accredited levee is designed to a specific flood level and can be overtopped or fail in a larger event, which is what "residual risk" means. Properties behind an accredited levee are often mapped out of the high-risk Special Flood Hazard Area, so flood insurance may not be federally required - but the risk behind the levee is real, and coverage is generally cheaper in those areas precisely because the mapped risk is lower.
What does a non-accredited levee mean for my flood zone?
If FEMA has not accredited a levee, it generally will not give the area behind it credit for reduced flood risk when drawing flood maps. That area is often mapped as if the levee were not there, which can place it in a high-risk zone with a mandatory flood insurance requirement for federally backed mortgages. A non-accredited levee may still be structurally sound - accreditation is about documentation submitted to FEMA, not a field inspection.
Where does this levee data come from?
The USACE National Levee Database, the public inventory maintained by the US Army Corps of Engineers, sourced August 2026. Accreditation status reflects the FEMA accreditation rating recorded in that database at extraction time and can change as communities submit documentation or FEMA revises a map.
Explore Flood Zones by State
Check flood zone information for cities across the United States.
Check for Levee Protection at Your Address
Enter any US address to see its FEMA flood zone, and whether a levee system covers the area.
Disclaimer: This guide is for general informational purposes only and is not a substitute for professional advice. Levee accreditation status changes as communities submit documentation and FEMA revises flood maps. Consult your local floodplain administrator or a certified floodplain manager for the current status of a specific levee system.