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, 7,777 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 | 1155 | 01/01/2001 |
| Texas | 938 | 01/03/2024 |
| Georgia | 468 | 01/01/2005 |
| Missouri | 452 | 01/01/1991 |
| South Carolina | 369 | 01/03/2024 |
| California | 337 | 01/06/2026 |
| Mississippi | 255 | 01/05/2023 |
| New York | 244 | 01/02/2024 |
| Pennsylvania | 243 | 01/04/2021 |
| Kansas | 242 | 01/03/2020 |
| Ohio | 216 | 01/21/2021 |
| Colorado | 200 | 01/09/2024 |
| Virginia | 188 | 01/06/2021 |
| Washington | 146 | 01/04/2019 |
| Tennessee | 145 | 01/04/2024 |
| Massachusetts | 135 | 01/05/2024 |
| West Virginia | 130 | 01/04/2016 |
| New Mexico | 129 | 01/14/2021 |
| Connecticut | 118 | 01/05/2024 |
| Kentucky | 117 | 01/29/2025 |
| Utah | 113 | 03/23/2023 |
| Nevada | 113 | 01/31/2022 |
| Oklahoma | 103 | 01/01/1980 |
| Indiana | 99 | 01/01/1962 |
| New Jersey | 90 | 01/04/2024 |
| Illinois | 90 | 02/02/2024 |
| Nebraska | 89 | 03/28/2024 |
| Hawaii | 77 | 01/09/2025 |
| Arizona | 77 | 01/08/2024 |
| Wisconsin | 65 | 02/22/2023 |
| Montana | 61 | 01/04/2021 |
| Arkansas | 55 | 01/01/2000 |
| New Hampshire | 48 | 03/23/2021 |
| Vermont | 45 | 01/01/1987 |
| Oregon | 45 | 01/20/2022 |
| Iowa | 43 | 03/15/2021 |
| Maryland | 42 | 01/29/2024 |
| Wyoming | 41 | 04/05/2022 |
| Michigan | 37 | 01/01/1901 |
| Idaho | 35 | 03/15/2023 |
| Florida | 32 | 01/29/2025 |
| Alabama | 32 | 01/04/2000 |
| Delaware | 28 | 04/11/2024 |
| Maine | 21 | 04/01/2022 |
| Puerto Rico | 18 | 01/10/2020 |
| South Dakota | 15 | 04/09/2023 |
| Minnesota | 15 | 02/23/2021 |
| Alaska | 7 | 05/20/2019 |
| North Dakota | 6 | 05/21/2025 |
| Louisiana | 4 | 04/10/2021 |
| Rhode Island | 3 | 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 |
| 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 |
| 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 |
| Carters Main Dam | Georgia | 464 | 05/09/2023 | 3 | Not Available | Yes |
| Detroit Dam | Oregon | 463 | 04/13/2026 | 0 | 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 |
| Swift No. 1 | Washington | 412 | 05/03/2022 | 4 | Fair | Yes |
| Harmar Refuse Bank | Pennsylvania | 410 | 04/02/2020 | 6 | Satisfactory | Yes |
| Little Blue Run | Pennsylvania | 400 | 03/26/2021 | 5 | Fair | Yes |
| Jordanelle Dam | Utah | 391 | 07/09/2020 | 6 | Not Available | 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 |
| 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 |
| 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 |
| Merwin | Washington | 313 | 04/19/2022 | 4 | Fair | 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 |
| Mathies Mine Refuse Area Pond #2 | Pennsylvania | 300 | 04/01/2021 | 5 | Fair | Yes |
| Lewis Smith | Alabama | 300 | 03/23/2022 | 4 | Satisfactory | Yes |
| Jennings Randolph Dam | Maryland | 296 | 06/03/2024 | 2 | Not Available | Yes |
| Seminoe Dam | Wyoming | 295 | 06/28/2023 | 3 | Not Available | Yes |
| Amistad Dam | Texas | 287 | 01/31/2024 | 2 | Poor | Yes |
| Diamond Valley Lake | California | 284 | 02/04/2025 | 1 | Satisfactory | 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 |
| Culmback | Washington | 262 | 05/14/2021 | 5 | Satisfactory | 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 |
| Ririe Dam | Idaho | 253 | 05/04/2021 | 5 | Not Available | Yes |
| Sugar Pine | California | 251 | 05/22/2025 | 1 | Satisfactory | Yes |
| Coolidge | Arizona | 250 | 02/24/2023 | 3 | Fair | Yes |
| Cedar Springs | California | 249 | 05/08/2025 | 1 | Fair | Yes |
| Mount Morris Dam | New York | 249 | 06/09/2025 | 1 | Not Available | Yes |
| Lost Creek Dam | Utah | 248 | 05/04/2022 | 4 | Not Available | Yes |
| Norfork Dam | Arkansas | 248 | 06/05/2024 | 2 | Not Available | Yes |
| Ball Mountain Dam | Vermont | 247 | 07/09/2024 | 2 | Not Available | Yes |
| Hughes Hollow Slurry Impoundment | Pennsylvania | 245 | 03/19/2021 | 5 | Satisfactory | Yes |
| Arthur R. Bowman Dam | Oregon | 245 | 06/22/2021 | 5 | Not Available | Yes |
| Pueblo Dam | Colorado | 245 | 04/10/2019 | 7 | Not Available | Yes |
| Oahe Dam - Fort Yates Flood Protection Project | South Dakota | 245 | 06/06/2023 | 3 | Not Available | Yes |
| Kortes Dam | Wyoming | 244 | 06/28/2023 | 3 | Not Available | Yes |
| Mcelroy Run Dam | West Virginia | 243 | 02/28/2025 | 1 | Satisfactory | Yes |
| Applegate Dam | Oregon | 242 | 05/14/2024 | 2 | Not Available | Yes |
| Deer Creek Dam | Utah | 240 | 07/08/2020 | 6 | Not Available | Yes |
| Blakely Mountain Dam | Arkansas | 240 | 04/25/2024 | 2 | Not Available | Yes |
| Mount St. Helens Sediment Retention Structure | Washington | 239 | 03/10/2022 | 4 | Not Available | Yes |
| El Capitan | California | 237 | 05/07/2025 | 1 | Poor | Yes |
| Smith Mountain Combination Pump Storage | Virginia | 237 | 04/13/2022 | 4 | Satisfactory | Yes |
| Conchas Dam | New Mexico | 235 | 05/30/2025 | 1 | Not Available | Yes |
| Tygart Dam | West Virginia | 234 | 04/26/2023 | 3 | Not Available | Yes |
| Chino Mines Tailings Dam No. 7 | New Mexico | 230 | 06/30/2020 | 6 | Satisfactory | Yes |
| Chief Joseph Dam | Washington | 230 | 06/21/2022 | 4 | Not Available | Yes |
| John Day Lock And Dam | Oregon | 230 | 01/20/2022 | 4 | Not Available | Yes |
| Pacificorp - Electric Lake | Utah | 229 | 06/20/2023 | 3 | Satisfactory | Yes |
| Trampas Canyon | California | 229 | 04/03/2025 | 1 | Satisfactory | Yes |
| Beaver Dam - Saddle Dike 3 | Arkansas | 229 | 06/09/2025 | 1 | Not Available | Yes |
| Sanford Dam | Texas | 228 | 03/03/2022 | 4 | Not Available | Yes |
| Little Goose Lock And Dam | Washington | 226 | 05/01/2023 | 3 | Not Available | Yes |
| New Lake Arrowhead | California | 225 | 05/22/2025 | 1 | Satisfactory | Yes |
| Salmon Falls | Idaho | 224 | 05/15/2020 | 6 | Fair | Yes |
| San Joaquin Reservoir | California | 224 | 05/07/2025 | 1 | Satisfactory | Yes |
| Mormon Flat Dam | Arizona | 224 | 02/05/2020 | 6 | Not Available | Yes |
| Canyon Lake Dam - Dike A | Texas | 224 | 02/02/2023 | 3 | Not Available | Yes |
| Canyon Lake Dam | Texas | 224 | 02/02/2023 | 3 | Not Available | Yes |