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, 5,847 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 | 1095 | 01/01/2001 |
| Texas | 665 | 01/03/2024 |
| Georgia | 452 | 01/01/2005 |
| Missouri | 324 | 01/01/1991 |
| South Carolina | 283 | 01/03/2024 |
| California | 245 | 01/06/2026 |
| Mississippi | 224 | 01/05/2023 |
| Kansas | 220 | 01/03/2020 |
| New York | 202 | 01/02/2024 |
| Pennsylvania | 188 | 01/04/2021 |
| Virginia | 158 | 01/06/2021 |
| Ohio | 118 | 01/21/2021 |
| Colorado | 106 | 01/09/2024 |
| Tennessee | 104 | 01/04/2024 |
| Massachusetts | 101 | 01/05/2024 |
| Nevada | 93 | 01/31/2022 |
| Connecticut | 89 | 01/05/2024 |
| New Mexico | 86 | 01/14/2021 |
| West Virginia | 85 | 01/04/2016 |
| Kentucky | 78 | 01/29/2025 |
| Washington | 76 | 01/04/2019 |
| Oklahoma | 76 | 01/01/1980 |
| New Jersey | 69 | 01/04/2024 |
| Hawaii | 66 | 01/09/2025 |
| Indiana | 64 | 01/01/1962 |
| Arizona | 63 | 01/08/2024 |
| Illinois | 61 | 02/02/2024 |
| Utah | 54 | 03/23/2023 |
| Nebraska | 44 | 03/28/2024 |
| Arkansas | 36 | 01/01/2000 |
| Wisconsin | 31 | 02/22/2023 |
| Montana | 30 | 01/04/2021 |
| New Hampshire | 29 | 03/23/2021 |
| Florida | 28 | 01/29/2025 |
| Alabama | 26 | 01/04/2000 |
| Maryland | 23 | 01/29/2024 |
| Oregon | 21 | 01/20/2022 |
| Idaho | 19 | 03/15/2023 |
| Delaware | 17 | 04/11/2024 |
| Puerto Rico | 16 | 01/10/2020 |
| Michigan | 14 | 01/01/1901 |
| Wyoming | 13 | 04/05/2022 |
| Maine | 12 | 04/01/2022 |
| Vermont | 11 | 01/01/1987 |
| Iowa | 11 | 03/15/2021 |
| Minnesota | 8 | 02/23/2021 |
| South Dakota | 6 | 04/09/2023 |
| Rhode Island | 2 | 03/28/2017 |
| Louisiana | 2 | 04/10/2021 |
| Alaska | 2 | 05/20/2019 |
| Guam | 1 | 05/07/2025 |
Largest Dams With Overdue Inspections
| Dam | State | Height (ft) | Last Inspection | Years Ago | Condition | EAP |
|---|---|---|---|---|---|---|
| Hoover Dam | Nevada | 730 | 02/09/2023 | 3 | 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| Bradbury Dam | California | 279 | 02/16/2023 | 3 | Not Available | Yes |
| Cushman No 2 | Washington | 275 | 05/19/2022 | 4 | Satisfactory | Yes |
| Cushman No 1 | Washington | 272 | 05/19/2022 | 4 | Fair | Yes |
| Palisades Dam | Idaho | 270 | 05/11/2021 | 5 | Not Available | Yes |
| Culmback | Washington | 262 | 05/14/2021 | 5 | Satisfactory | Yes |
| Ririe Dam | Idaho | 253 | 05/04/2021 | 5 | Not Available | Yes |
| Coolidge | Arizona | 250 | 02/24/2023 | 3 | Fair | Yes |
| Cedar Springs | California | 249 | 05/08/2025 | 1 | Fair | Yes |
| Lost Creek Dam | Utah | 248 | 05/04/2022 | 4 | Not Available | Yes |
| Hughes Hollow Slurry Impoundment | Pennsylvania | 245 | 03/19/2021 | 5 | Satisfactory | Yes |
| Pueblo Dam | Colorado | 245 | 04/10/2019 | 7 | 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 |
| 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 |
| Tygart Dam | West Virginia | 234 | 04/26/2023 | 3 | Not Available | Yes |
| John Day Lock And Dam | Oregon | 230 | 01/20/2022 | 4 | Not Available | Yes |
| Trampas Canyon | California | 229 | 04/03/2025 | 1 | Satisfactory | 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 |
| 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 |
| Cheesman | Colorado | 221 | 05/04/2022 | 4 | Satisfactory | Yes |
| La Grande | Washington | 217 | 01/23/2023 | 3 | Satisfactory | Yes |
| Toa Vaca Dam | Puerto Rico | 215 | 04/16/2019 | 7 | Satisfactory | Yes |
| King Branch Slurry Dam | Kentucky | 214 | 04/08/2021 | 5 | Not Available | Yes |
| Santa Rosa Dam | New Mexico | 214 | 04/07/2022 | 4 | Not Available | Yes |
| Greybull Valley (1st Enl.) | Wyoming | 207 | 05/14/2024 | 2 | Fair | Yes |
| Wanapum | Washington | 206 | 04/03/2023 | 3 | Fair | Yes |
| Brushy Creek Tailings | Missouri | 205 | 01/05/2022 | 4 | Satisfactory | Yes |
| Ralston | Colorado | 204 | 04/21/2022 | 4 | Satisfactory | Yes |
| Downsville Dam | New York | 204 | 05/09/2024 | 2 | Satisfactory | Yes |
| Lake Loveland | California | 203 | 02/05/2025 | 1 | Satisfactory | Yes |
| Camp Far West | California | 203 | 03/27/2023 | 3 | Fair | Yes |
| Trinidad Dam | Colorado | 203 | 03/31/2022 | 4 | Not Available | Yes |
| Cedar Bluff Dam | Kansas | 202 | 04/08/2022 | 4 | Not Available | Yes |
| Douglas Dam | Tennessee | 202 | 02/10/2025 | 1 | Not Available | Yes |
| Fletcher Tailings Dam | Missouri | 201 | 01/05/2009 | 17 | Unsatisfactory | Yes |
| Garzas Dam | Puerto Rico | 201 | 05/02/2019 | 7 | Unsatisfactory | Yes |
| Cornwall Tailings | Pennsylvania | 200 | 03/30/2021 | 5 | Fair | Yes |
| Barrick Goldstrike Tsf 3 Dam | Nevada | 200 | 05/13/2020 | 6 | Not Rated | Yes |
| Davis Dam | Arizona | 200 | 03/18/2022 | 4 | Not Available | Yes |
| Dale Hollow Dam | Tennessee | 200 | 03/27/2023 | 3 | Not Available | Yes |
| The Dalles Lock And Dam | Oregon | 200 | 04/12/2023 | 3 | Not Available | Yes |
| Stillhouse Hollow Dam - Dike | Texas | 200 | 05/13/2021 | 5 | Not Available | Yes |
| Stillhouse Hollow Dam | Texas | 200 | 05/13/2021 | 5 | Not Available | Yes |
| Tenkiller Ferry Dam - Dike | Oklahoma | 197 | 05/08/2019 | 7 | Not Available | Yes |
| Spring Creek Debris Dam | California | 196 | 03/09/2020 | 6 | Not Available | Yes |
| Whale Rock | California | 193 | 01/28/2025 | 1 | Satisfactory | Yes |
| Belton Dam | Texas | 192 | 04/15/2024 | 2 | Not Available | Yes |
| Betsie Branch Refuse Impoundment | Kentucky | 191 | 03/03/2021 | 5 | Not Available | Not Required |
| Cherry Creek Dam | Colorado | 189 | 03/24/2025 | 1 | Not Available | Yes |
| Dos Bocas Dam | Puerto Rico | 188 | 02/07/2020 | 6 | Satisfactory | Yes |
| Priest Rapids | Washington | 187 | 04/16/2025 | 1 | Fair | Yes |
| Isabella Dam | California | 185 | 01/15/2026 | 0 | Not Available | Yes |
| Barker Meadow | Colorado | 184 | 04/13/2022 | 4 | Satisfactory | Yes |
| Youghiogheny Dam | Pennsylvania | 184 | 05/05/2025 | 1 | Not Available | Yes |
| East Branch Dam | Pennsylvania | 184 | 04/29/2022 | 4 | Not Available | Yes |
| Black Canyon Diversion Dam | Idaho | 183 | 04/01/2021 | 5 | Not Available | Yes |