High Hazard Dams With Overdue Inspections
High hazard dams — those where failure would probably cause loss of human life — typically require regular inspections to identify safety deficiencies before they become emergencies. Most states mandate inspections every 1-5 years for high hazard dams.
Currently, 9,647 high hazard dams in the National Inventory of Dams show a last inspection date more than 5 years ago. While some of these may reflect data reporting delays rather than missed inspections, the gap between the recorded inspection date and today raises questions about ongoing monitoring.
This data comes from the NID and may not reflect inspections conducted but not yet reported to federal databases. For the most current inspection status, contact your state dam safety program.
Overdue Inspections by State
| State | Overdue High Hazard Dams | Oldest Inspection |
|---|---|---|
| North Carolina | 1230 | 01/01/2001 |
| Texas | 1096 | 01/03/2024 |
| Missouri | 567 | 01/01/1991 |
| Georgia | 480 | 01/01/2005 |
| California | 460 | 01/06/2026 |
| South Carolina | 435 | 01/03/2024 |
| Colorado | 321 | 01/09/2024 |
| Pennsylvania | 313 | 01/04/2021 |
| New York | 305 | 01/02/2024 |
| Mississippi | 269 | 01/05/2023 |
| Kansas | 260 | 01/03/2020 |
| Washington | 254 | 01/04/2019 |
| Virginia | 245 | 01/06/2021 |
| Ohio | 228 | 01/21/2021 |
| West Virginia | 179 | 01/04/2016 |
| Tennessee | 177 | 01/04/2024 |
| Utah | 173 | 03/23/2023 |
| Massachusetts | 163 | 01/05/2024 |
| Indiana | 163 | 01/01/1962 |
| Oklahoma | 142 | 01/01/1980 |
| Kentucky | 139 | 01/29/2025 |
| New Mexico | 136 | 01/14/2021 |
| Connecticut | 134 | 01/05/2024 |
| Nevada | 132 | 01/31/2022 |
| Illinois | 124 | 02/02/2024 |
| Wisconsin | 112 | 02/22/2023 |
| New Jersey | 106 | 01/04/2024 |
| Nebraska | 105 | 03/28/2024 |
| Montana | 102 | 01/04/2021 |
| Arkansas | 97 | 01/01/2000 |
| Hawaii | 89 | 01/09/2025 |
| Arizona | 83 | 01/08/2024 |
| Michigan | 82 | 01/01/1901 |
| Oregon | 79 | 01/20/2022 |
| New Hampshire | 78 | 03/23/2021 |
| Wyoming | 73 | 04/05/2022 |
| Vermont | 65 | 01/01/1987 |
| Iowa | 59 | 03/15/2021 |
| Idaho | 56 | 03/15/2023 |
| Florida | 49 | 01/29/2025 |
| Maryland | 48 | 01/29/2024 |
| Maine | 42 | 04/01/2022 |
| Alabama | 40 | 01/04/2000 |
| South Dakota | 34 | 04/09/2023 |
| Delaware | 28 | 04/11/2024 |
| Minnesota | 23 | 02/23/2021 |
| Puerto Rico | 22 | 01/10/2020 |
| Alaska | 21 | 05/20/2019 |
| North Dakota | 12 | 05/21/2025 |
| Louisiana | 12 | 04/10/2021 |
| Rhode Island | 4 | 03/28/2017 |
| Guam | 1 | 05/07/2025 |
Largest Dams With Overdue Inspections
| Dam | State | Height (ft) | Last Inspection | Years Ago | Condition | EAP |
|---|---|---|---|---|---|---|
| Thompson Mtis | Idaho | 789 | 06/05/2019 | 7 | Fair | Yes |
| Oroville | California | 770 | 06/06/2023 | 3 | Fair | Yes |
| Hoover Dam | Nevada | 730 | 02/09/2023 | 3 | Not Available | Yes |
| Dworshak Dam | Idaho | 717 | 06/23/2022 | 4 | Not Available | Yes |
| New Melones Dam | California | 625 | 04/27/2022 | 4 | Not Available | Yes |
| Mossyrock | Washington | 606 | 08/20/2025 | 1 | Unsatisfactory | Yes |
| Shasta Dam | California | 602 | 02/11/2022 | 4 | Not Available | Yes |
| Yankee Doodle Tailings Dam | Montana | 570 | 02/12/2020 | 6 | Satisfactory | Yes |
| Hungry Horse Dam | Montana | 564 | 06/24/2021 | 5 | Not Available | Yes |
| Ross | Washington | 540 | 08/15/2022 | 4 | Satisfactory | Yes |
| Trinity Dam | California | 538 | 04/20/2022 | 4 | Not Available | Yes |
| Yellowtail Dam | Montana | 525 | 04/25/2023 | 3 | Not Available | Yes |
| North Block Tailings Impoundment Dam | Nevada | 520 | 05/13/2020 | 6 | Not Rated | Yes |
| Cougar Dam | Oregon | 519 | 05/17/2022 | 4 | Not Available | Yes |
| Flaming Gorge Dam | Utah | 502 | 06/29/2022 | 4 | Not Available | Yes |
| Fontana Dam | North Carolina | 480 | 02/15/2024 | 2 | Not Available | Yes |
| Morrow Point Dam | Colorado | 468 | 07/19/2023 | 3 | Not Available | Yes |
| Carters Main Dam | Georgia | 464 | 05/09/2023 | 3 | Not Available | Yes |
| Detroit Dam | Oregon | 463 | 04/13/2026 | 0 | Not Available | Yes |
| Anderson Ranch Dam | Idaho | 456 | 07/27/2021 | 5 | Not Available | Yes |
| Round Butte | Oregon | 440 | 06/08/2022 | 4 | Fair | Yes |
| New Waddell Dam | Arizona | 440 | 04/19/2022 | 4 | Not Available | Yes |
| Pine Flat Dam | California | 440 | 05/20/2021 | 5 | Not Available | Yes |
| Mud Mountain Dam | Washington | 425 | 05/15/2021 | 5 | Not Available | Yes |
| Pyramid | California | 422 | 05/06/2025 | 1 | Fair | Yes |
| Libby Dam | Montana | 422 | 07/16/2025 | 1 | Not Available | Yes |
| Owyhee Dam | Oregon | 417 | 07/14/2022 | 4 | Not Available | Yes |
| Swift No. 1 | Washington | 412 | 05/03/2022 | 4 | Fair | Yes |
| Harmar Refuse Bank | Pennsylvania | 410 | 04/02/2020 | 6 | Satisfactory | Yes |
| Hell Hole | California | 410 | 08/22/2023 | 3 | Fair | Yes |
| Little Blue Run | Pennsylvania | 400 | 03/26/2021 | 5 | Fair | Yes |
| Jordanelle Dam | Utah | 391 | 07/09/2020 | 6 | Not Available | Yes |
| Blue Mesa Dam | Colorado | 390 | 07/18/2023 | 3 | Not Available | Yes |
| Diablo | Washington | 389 | 08/16/2022 | 4 | Satisfactory | Yes |
| Green Peter Dam | Oregon | 378 | 06/11/2025 | 1 | Not Available | Yes |
| Boundary | Washington | 360 | 05/24/2022 | 4 | Fair | Yes |
| Abiquiu Dam | New Mexico | 354 | 04/25/2023 | 3 | Not Available | Yes |
| Arrowrock Dam | Idaho | 350 | 05/05/2021 | 5 | Not Available | Yes |
| Hills Creek Dam | Oregon | 341 | 07/12/2023 | 3 | Not Available | Yes |
| San Vicente | California | 338 | 07/23/2024 | 2 | Satisfactory | Yes |
| Bailey Mine Area No. 3 Slurry | Pennsylvania | 337 | 08/03/2020 | 6 | Satisfactory | Yes |
| Watauga Dam | Tennessee | 332 | 03/27/2025 | 1 | Not Available | Yes |
| Alder | Washington | 330 | 01/23/2023 | 3 | Satisfactory | Yes |
| Ridgway Dam | Colorado | 330 | 06/10/2020 | 6 | Not Available | Yes |
| Salt Springs | California | 328 | 08/20/2025 | 1 | Satisfactory | Yes |
| Crystal Dam | Colorado | 323 | 07/20/2023 | 3 | Not Available | Yes |
| Cerrillos Dam | Puerto Rico | 323 | 06/16/2021 | 5 | Satisfactory | Yes |
| Ruedi Dam | Colorado | 322 | 05/16/2022 | 4 | Not Available | Yes |
| Parker Dam | Arizona | 320 | 03/11/2022 | 4 | Not Available | Yes |
| Donnells | California | 317 | 07/25/2023 | 3 | Satisfactory | Yes |
| Courtright | California | 315 | 08/17/2023 | 3 | Satisfactory | Yes |
| Bailey Mine Slurry Impoundment | Pennsylvania | 315 | 08/03/2020 | 6 | Satisfactory | Yes |
| Merwin | Washington | 313 | 04/19/2022 | 4 | Fair | Yes |
| Dillon | Colorado | 310 | 07/27/2022 | 4 | Satisfactory | Yes |
| Cobre Main Tailings Dam | New Mexico | 310 | 07/01/2020 | 6 | Satisfactory | Yes |
| Olivenhain | California | 309 | 05/28/2025 | 1 | Satisfactory | Yes |
| Bartlett Dam | Arizona | 309 | 03/04/2020 | 6 | Not Available | Yes |
| Green Mountain Dam | Colorado | 309 | 01/09/2024 | 2 | Not Available | Yes |
| Hiwassee Dam | North Carolina | 307 | 04/09/2025 | 1 | Not Available | Yes |
| Horse Mesa Dam | Arizona | 305 | 04/05/2023 | 3 | Not Available | Yes |
| Monticello Dam | California | 304 | 03/10/2020 | 6 | Not Available | Yes |
| Gorge | Washington | 300 | 08/17/2022 | 4 | Satisfactory | Yes |
| Mathies Mine Refuse Area Pond #2 | Pennsylvania | 300 | 04/01/2021 | 5 | Fair | Yes |
| Lewis Smith | Alabama | 300 | 03/23/2022 | 4 | Satisfactory | Yes |
| Sly Creek | California | 299 | 08/22/2023 | 3 | Satisfactory | Yes |
| Granby Dam | Colorado | 298 | 08/06/2020 | 6 | Not Available | Yes |
| Jennings Randolph Dam | Maryland | 296 | 06/03/2024 | 2 | Not Available | Yes |
| Seminoe Dam | Wyoming | 295 | 06/28/2023 | 3 | Not Available | Yes |
| Blue Lake | Alaska | 294 | 08/01/2022 | 4 | Satisfactory | Yes |
| Upper Stillwater Dam | Utah | 292 | 08/04/2021 | 5 | Not Available | Yes |
| Amistad Dam | Texas | 287 | 01/31/2024 | 2 | Poor | Yes |
| Lower Baker | Washington | 285 | 07/11/2022 | 4 | Poor | Yes |
| South Holston Dam | Tennessee | 285 | 07/10/2024 | 2 | Not Available | Yes |
| Diamond Valley Lake | California | 284 | 02/04/2025 | 1 | Satisfactory | Yes |
| Lemon Dam | Colorado | 284 | 08/23/2022 | 4 | Not Available | Yes |
| Beardsley | California | 284 | 07/25/2023 | 3 | Fair | Yes |
| Alamo Dam | Arizona | 283 | 02/19/2025 | 1 | Not Available | Yes |
| Laurel Dam | Kentucky | 282 | 03/30/2022 | 4 | Not Available | Yes |
| Merrill Creek Main Dam | New Jersey | 280 | 06/12/2024 | 2 | Satisfactory | Yes |
| Harry L. Englebright Dam | California | 280 | 06/27/2024 | 2 | Not Available | Yes |
| Bradbury Dam | California | 279 | 02/16/2023 | 3 | Not Available | Yes |
| Lookout Point Dam | Oregon | 276 | 06/13/2024 | 2 | Not Available | Yes |
| Cushman No 2 | Washington | 275 | 05/19/2022 | 4 | Satisfactory | Yes |
| Ridges Basin Dam | Colorado | 273 | 06/28/2023 | 3 | Not Available | Yes |
| Soldier Creek Dam | Utah | 272 | 06/08/2021 | 5 | Not Available | Yes |
| Cushman No 1 | Washington | 272 | 05/19/2022 | 4 | Fair | Yes |
| Palisades Dam | Idaho | 270 | 05/11/2021 | 5 | Not Available | Yes |
| Alcova Dam | Wyoming | 265 | 06/09/2021 | 5 | Not Available | Yes |
| New Spicer Meadow | California | 265 | 08/09/2022 | 4 | Satisfactory | Yes |
| Homestake Project | Colorado | 265 | 08/17/2022 | 4 | Satisfactory | Yes |
| Culmback | Washington | 262 | 05/14/2021 | 5 | Satisfactory | Yes |
| Noxon Rapids | Montana | 260 | 07/26/2022 | 4 | Fair | Yes |
| East Canyon Dam | Utah | 260 | 06/01/2023 | 3 | Not Available | Yes |
| Table Rock Dam | Missouri | 260 | 05/24/2023 | 3 | Not Available | Yes |
| Wolf Creek Dam | Kentucky | 258 | 07/15/2025 | 1 | Not Available | Yes |
| Gathright Dam | Virginia | 257 | 08/18/2025 | 1 | Not Available | Yes |
| Mccloud | California | 255 | 08/02/2023 | 3 | Fair | Yes |
| Ririe Dam | Idaho | 253 | 05/04/2021 | 5 | Not Available | Yes |
| Sugar Pine | California | 251 | 05/22/2025 | 1 | Satisfactory | Yes |
| Cochiti Dam | New Mexico | 251 | 07/22/2022 | 4 | Not Available | Yes |